Journal of Vascular and Interventional Radiology, May 1, 1999
The intent of this systematic overview was to describe the clinical role of metal stents in nonva... more The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use. Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English. Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief. Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.
The Cleft Palate-Craniofacial Journal, Mar 1, 1992
Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A stu... more Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
The Cleft Palate-Craniofacial Journal, Mar 1, 1992
Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A stu... more Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
Objective: The main objectives for this evidence-based analysis were to determine the safety and ... more Objective: The main objectives for this evidence-based analysis were to determine the safety and effectiveness of photochemical corneal collagen cross-linking with riboflavin (vitamin B(2)) and ultraviolet-A radiation, referred to as CXL, for the management of corneal thinning disease conditions. The comparative safety and effectiveness of corneal cross-linking with other minimally invasive treatments such as intrastromal corneal rings was also reviewed. The Medical Advisory Secretariat (MAS) evidence-based analysis was performed to support public financing decisions. SUBJECT OF THE EVIDENCE-BASED ANALYSIS: The primary treatment objective for corneal cross-linking is to increase the strength of the corneal stroma, thereby stabilizing the underlying disease process. At the present time, it is the only procedure that treats the underlying disease condition. The proposed advantages for corneal cross-linking are that the procedure is minimally invasive, safe and effective, and it can potentially delay or defer the need for a corneal transplant. In addition, corneal cross-linking does not adversely affect subsequent surgical approaches, if they are necessary, or interfere with corneal transplants. The evidence for these claims for corneal cross-linking in the management of corneal thinning disorders such as keratoconus will be the focus of this review. The specific research questions for the evidence review were as follows: TECHNICAL: How technically demanding is corneal cross-linking and what are the operative risks? Safety: What is known about the broader safety profile of corneal cross-linking?Effectiveness - Corneal Surface Topographic Affects:What are the corneal surface remodeling effects of corneal cross-linking?Do these changes interfere with subsequent interventions, particularly corneal transplant known as penetrating keratoplasty (PKP)?Effectiveness -Visual Acuity:What impacts does the remodeling have on visual acuity?Are these impacts predictable, stable, adjustable and durable?Effectiveness - Refractive Outcomes: What impact does remodeling have on refractive outcomes?Effectiveness - Visual Quality (Symptoms): What impact does corneal cross-linking have on vision quality such as contrast vision, and decreased visual symptoms (halos, fluctuating vision)?Effectiveness - Contact lens tolerance: To what extent does contact lens intolerance improve after corneal cross-linking?Vision-Related QOL: What is the impact of corneal cross-linking on functional visual rehabilitation and quality of life?PATIENT SATISFACTION: Are patients satisfied with their vision following the procedure?Disease Process:What impact does corneal cross-linking have on the underling corneal thinning disease process?Does corneal cross-linking delay or defer the need for a corneal transplant?What is the comparative safety and effectiveness of corneal cross-linking compared with other minimally invasive treatments for corneal ectasia such as intrastromal corneal rings? Clinical need: TARGET POPULATION AND CONDITION Corneal ectasia (thinning) disorders represent a range of disorders involving either primary disease conditions, such as keratoconus (KC) and pellucid marginal corneal degeneration, or secondary iatrogenic conditions, such as corneal thinning occurring after laser in situ keratomileusis (LASIK) refractive surgery. Corneal thinning is a disease that occurs when the normally round dome-shaped cornea progressively thins causing a cone-like bulge or forward protrusion in response to the normal pressure of the eye. The thinning occurs primarily in the stroma layers and is believed to be a breakdown in the collagen process. This bulging can lead to irregular astigmatism or shape of the cornea. Because the anterior part of the cornea is responsible for most of the focusing of the light on the retina, this can then result in loss of visual acuity. The reduced visual acuity can make even simple daily tasks, such as driving, watching television or reading, difficult to perform. Keratoconus is the most common form of corneal thinning disorder and involves a noninflammatory chronic disease process of progressive corneal thinning. Although the specific cause for the biomechanical alterations in the corneal stroma is unknown, there is a growing body of evidence suggesting that genetic factors may play an important role. Keratoconus is a rare disease (< 0.05% of the population) and is unique among chronic eye diseases because it has an early onset, with a median age of 25 years. Disease management for this condition follows a step-wise approach depending on disease severity. Contact lenses are the primary treatment of choice when there is irregular astigmatism associated with the disease. Patients are referred for corneal transplants as a last option when they can no longer tolerate contact lenses or when lenses no longer provide adequate vision. Keratoconus is one of the leading indications for corneal transplants and has been so for the last 3 decades. Despite the high success rate of corneal transplants (up to 20 years) there are reasons to defer it as long as possible. Patients with keratoconus are generally young and a longer-term graft survival of at least 30 or 40 years may be necessary. The surgery itself involves lengthy time off work and postsurgery, while potential complications include long-term steroid use, secondary cataracts, and glaucoma. After a corneal transplant, keratoconus may recur resulting in a need for subsequent interventions. Residual refractive errors and astigmatism can remain challenges after transplantation, and high refractive surgery and regraft rates in KC patients have been reported. Visual rehabilitation or recovery of visual acuity after transplant may be slow and/or unsatisfactory to patients. Description of technology/therapy: Corneal cross-linking involves the use of riboflavin (vitamin B(2)) and ultraviolet-A (UVA) radiation. A UVA irradiation device known as the CXL® device (license number 77989) by ACCUTECH Medical Technologies Inc. has been licensed by Health Canada as a Class II device since September 19, 2008. An illumination device that emits homogeneous UVA, in combination with any generic form of riboflavin, is licensed by Health Canada for the indication to slow or stop the progression of corneal thinning caused by progressive keratectasia, iatrogenic keratectasia after laser-assisted in situ keratomileusis (LASIK) and pellucid marginal degeneration. The same device is named the UV-X® device by IROCMedical, with approvals in Argentina, the European Union and Australia. UVA devices all use light emitting diodes to generate UVA at a wavelength of 360-380 microns but vary in the number of diodes (5 to 25), focusing systems, working distance, beam diameter, beam uniformity and extent to which the operator can vary the parameters. In Ontario, CXL is currently offered at over 15 private eye clinics by refractive surgeons and ophthalmologists. The treatment is an outpatient procedure generally performed with topical anesthesia. The treatment consists of several well defined procedures. The epithelial cell layer is first removed, often using a blunt spatula in a 9.0 mm diameter under sterile conditions. This step is followed by the application of topical 0.1% riboflavin (vitamin B(2)) solution every 3 to 5 minutes for 25 minutes to ensure that the corneal stroma is fully penetrated. A solid-state UVA light source with a wavelength of 370 nm (maximum absorption of riboflavin) and an irradiance of 3 mW/cm(2) is used to irradiate the central cornea. Following treatment, a soft bandage lens is applied and prescriptions are given for oral pain medications, preservative-free tears, anti-inflammatory drops (preferably not nonsteroidal anti-inflammatory drugs, or NSAIDs) and antibiotic eye drops. Patients are recalled 1 week following the procedure to evaluate re-epithelialization and they are followed-up subsequently. Evidence-based analysis methods: A literature search was conducted on photochemical corneal collagen cross-linking with riboflavin (vitamin B(2)) and ultraviolet-A for the management of corneal thinning disorders using a search strategy with appropriate keywords and subject headings for CXL for literature published up until April 17, 2011. The literature search for this Health Technology Assessment (HTA) review was performed using the Cochrane Library, the Emergency Care Research Institute (ECRI) and the Centre for Reviews and Dissemination. The websites of several other health technology agencies were also reviewed, including the Canadian Agency for Drugs and Technologies in Health (CADTH) and the United Kingdom's National Institute for Clinical Excellence (NICE). The databases searched included OVID MEDLINE, MEDLINE IN-Process and other Non-Indexed Citations such as EMBASE. As the evidence review included an intervention for a rare condition, case series and case reports, particularly for complications and adverse events, were reviewed. A total of 316 citations were identified and all abstracts were reviewed by a single reviewer for eligibility. For those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. (ABSTRACT TRUNCATED)
ABSTRACT Computed tomography (CT) is a useful modality for the management of craniofacial anomali... more ABSTRACT Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
BACKGROUND CONTEXT Osteoporotic vertebral fractures (OVF) dramatically increase with age and are ... more BACKGROUND CONTEXT Osteoporotic vertebral fractures (OVF) dramatically increase with age and are serious life altering adverse events for seniors resulting in increased rates of institutionalization, morbidity and mortality. Given the expanding population of the elderly and increasing prevalence of OVFs, cost-effective treatment strategies need to be considered. Percutaneous vertebral augmentation (VA) procedures such as vertebroplasty (VP) or balloon kyphoplasty (BK) are increasingly employed to treat painful vertebral fractures not responding to conservative management (CM) of bedrest and analgesia. Both VA procedures have been shown to be effective treatments for OVFs in multiple systematic reviews of randomized controlled trials. In this systematic review, analytical strategies, designs and results were compared for health economic studies evaluating cost-effectiveness of VA procedures, VP or BK for OVFs. Furthermore, assessments of quality (risk of bias) were conducted for the systematic review and the individual studies with peer-reviewed checklists recommended for cost-effectiveness studies. PURPOSE To provide an up-to-date systematic review of peer-reviewed studies evaluating cost-effectiveness of VA procedures, VP or KP for OVFs to support treatment and healthcare funding decisions. STUDY DESIGN This study is a systematic literature review and structured narrative synthesis. STUDY SAMPLE Peer reviewed health economic studies reporting cost-effectiveness for VA procedures, VP or BK for OVFs OUTCOME MEASURES: The following information extracted from the studies included: report country and year, study design, comparators, population, perspective, health valuations, costing sources and cost-effectiveness measures. For economic studies involving modeling, information was also extracted for model type, time horizon, key model drivers, and handling of uncertainty. Incremental cost-effectiveness ratio (ICER), the ratio of differences between comparator treatment groups in costs and health benefits, was considered the main cost-effectiveness measure. METHODS A systematic review was conducted of MEDLINE, EMBASE, CINAHL, ECONLIT, Cochrane Library and DARE databases up to the review date May 2021. Studies were reviewed for those reporting cost-effectiveness analyses on VA procedures including VP or BK for OVFs. Studies including only costs, abstracts, editorials, methodologies and reviews were not included. The selection of articles was reported in line with PRISMA guidance. A descriptive framework was developed to classify types of cost-effectiveness studies based on methodological differences and a structured narrative synthesis was used to summarize studies. Quality assessments were made with British Medical Journal checklist for individual cost-effectiveness studies and the CiCERO checklist for systematic reviews of cost-effectiveness studies. RESULTS In this systematic review, 520 references were identified through database searching and 501 were excluded as ineligible by titles and abstract based on prior eligibility criteria. From full-text reviews of 19 reports, ten were identified as eligible for the systematic review evaluating cost-effectiveness of VA procedures for OVFs. All references were published between 2008 and 2020. The ten cost-effectiveness studies, three for VP, three for BK and four for both VP and BK, all involved CM for OVFs as a treatment comparator. The studies involved different methods of economic analysis, modeling assumptions, cost and health valuations conducted in different healthcare setting over different time periods. A framework for the review outlines key features of cost-effectiveness study designs consisting of unmatched, matched, or randomized controls involving cost-effectiveness (CEA) or cost-utility (CUA)) analyses. Both VP and BK were cost-effective alternatives to CM for OVFs with earlier health gains and significantly shorter hospital stays. Cost-effectiveness estimates, ICERs, remained relatively stable and within willingness-to-pay thresholds under a range of sensitivity analyses. Comparisons between VP and BK were variable depending on modeling assumptions, but generally the procedures had similar health benefit gains with VP having lower acute procedural costs. CONCLUSIONS Both VP and BK, have been shown to be cost-effective alternatives to CM for osteoporotic vertebral fractures in diverse cost-effectiveness studies conducted in multiple healthcare settings. Trial-based CUA contributed the strongest evidence supporting cost-effectiveness determination for VP and BK for OVFs.
ObjectiveAlthough there is substantial clinical evidence on the safety and effectiveness of verte... more ObjectiveAlthough there is substantial clinical evidence on the safety and effectiveness of vertebral augmentation for osteoporotic vertebral fractures, cost-effectiveness is less well known. The objective of this study is to provide a systematic review of cost-effectiveness studies and policy-based willingness-to-pay (WTP) thresholds for different vertebral augmentation (VA) procedures, vertebroplasty (VP) and balloon kyphoplasty (BK), for osteoporotic vertebral fractures (OVFs).DesignA systematic review targeting cost-effectiveness studies of VA procedures for OVFs.Data sourcesSix bibliographic databases were searched from inception up to May 2021.Eligibility criteria for study selectionStudies were eligible if meeting all predefined criteria: (1) VP or BK intervention, (2) OVFs and (3) cost-effectiveness study. Articles not written in English, abstracts, editorials, reviews and those reporting only cost data were excluded.Data extraction and synthesisInformation was extracted on study characteristics, cost-effective estimates, summary decisions and payer WTP thresholds. Incremental cost-effective ratio (ICER) was the main outcome measure. Studies were summarised by a structured narrative synthesis organised by comparisons with conservative management (CM). Two independent reviewers assessed the quality (risk of bias) of the systematic review and cost-effectiveness studies by peer-reviewed checklists.ResultsWe identified 520 references through database searching and 501 were excluded as ineligible by titles and abstract. Ten reports were identified as eligible from 19 full-text reviews. ICER for VP versus CM evaluated as cost per quality-adjusted life-year (QALY) ranged from €22 685 (*US$33 395) in Netherlands to £−2240 (*US$−3273), a cost-saving in the UK. ICERs for BK versus CM ranged from £2706 (*US$3954) in UK to kr600 000 (*US$90 910) in Sweden. ICERs were within payer WTP thresholds for a QALY based on historical benchmarks.ConclusionsBoth VP and BK were judged cost-effective alternatives to CM for OVFs in economic studies and were within WTP thresholds in multiple healthcare settings.
Background: New anti-angiogenesis pharmacotherapies have dramatically altered treatment of age-re... more Background: New anti-angiogenesis pharmacotherapies have dramatically altered treatment of age-related macular degeneration (AMD), the leading cause of blindness in older adults. Monthly intraocular injections however, are extremely burdensome to ophthalmologists, patients, and their families. Repeated injections also increase risks of complications or adverse events. Although the pharmacokinetics of anti-vascular endothelial growth factor (A-VEGF) drugs are fairly well known, an individuals' AMD presentation and their pharmacodynamics or response to the drug has been shown to be extremely variable. Therefore treating everyone on the same fixed or standard regimen has potential for undertreating or overtreating patients, and drug costs are not trivial. Objectives: To review monitoring strategies and to evaluate the role of optical coherence tomography (OCT) in guiding management of A-VEGF-treated neovascular AMD (n-AMD) patients. Data sources: Systematic reviews of biographic databases for studies published between 2008 and February 2013 involving A-VEGF-treated n-AMD patients monitored in longitudinal follow-up. Review methods: Studies were grouped according to varying treatments, monitoring schedules, and re-treatment protocols reported for n-AMD patients treated with A-VEGF. Several outcomes were evaluated across strategies including visual acuity (VA), retinal anatomy, re-treatment criteria and frequencies of clinical follow-up, OCT imaging investigations, and intravitreal injections. Results were summarized qualitatively, as heterogeneity in study objectives and methods precluded formal meta-analysis. Results: A systematic review identified 18 randomized controlled trials (RCTs) and 20 observational studies involving A-VEGF treatment employing various monitoring and as-needed (PRN) re-treatment protocols. Several maintenance strategies were unsuccessful, resulting in lower VA gains and stabilization than monthly injections in A-VEGF-treated n-AMD. These included fixed quarterly treatment; fixed quarterly monitoring and PRN re-treatment; and monthly monitoring with either VA-guided re-treatment or quantitative-only VA/OCT- (central retinal thickness [CRT] > 100 μm) guided re-treatment. PRN re-treatment strategies with A-VEGF on the basis of monthly follow-up and rigorous reviews of OCT qualitative and quantitative measures of disease activity did decrease injection burden while maintaining visual gains. Gains in VA obtained with PRN re-treatment in usual clinical practice, however, were not as high as gains in clinical trials. Conclusions: To reduce treatment burden and provide a more individualized treatment strategy for n-AMD patients, OCT/VA-guided PRN treatment strategies have become the preferred and the dominant maintenance strategy. Success of these strategies, however, is dependent on close monitoring and adherence to tightly defined re-treatment criteria.
Background: Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and t... more Background: Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and their second or third leading cause of cancer death. Prostate-specific antigen (PSA) testing for PC has been in common practice for more than 20 years. Objectives: A systematic review of the scientific literature was conducted to determine the effectiveness of PSA-based population screening programs for PC to inform policy decisions in a publicly funded health care system. Data sources: A systematic review of bibliographic databases was performed for systematic reviews or randomized controlled trials (RCT) of PSA-based population screening programs for PC. Review methods: A broad search strategy was employed to identify studies reporting on key outcomes of PC mortality and all-cause mortality. Results: The search identified 5 systematic reviews and 6 RCTs. None of the systematic reviews found a statistically significant reduction in relative risk (RR) of PC mortality or overall mortality with PSA-based screening. PC mortality reductions were found to vary by country, by screening program, and by age of men at study entry. The European Randomized Study of Screening for Prostate Cancer found a statistically significant reduction in RR in PC mortality at 11-year follow-up (0.79; 95% CI, 0.67-0.92), although the absolute risk reduction was small (1.0/10,000 person-years). However, the primary treatment for PCs differed significantly between countries and between trial arms. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) found a statistically non-significant increase in RR for PC mortality with 13-year follow-up (1.09; 95% CI, 0.87-1.36). The degree of opportunistic screening in the control arm of the PLCO trial, however, was high. None of the RCTs found a reduction in all-cause mortality and all found a statistically significant increase in the detection of mainly low-risk, organ-confined PCs in the screening arm. Conclusions: There was no evidence of a PC mortality reduction in the American PLCO trial, which investigated a screening program in a setting where opportunistic screening was already common practice. Given that opportunistic PSA screening practices in Canada are similar, it is unlikely that the introduction of a formal PSA screening program would reduce PC mortality.
Journal of Vascular and Interventional Radiology, May 1, 1999
The intent of this systematic overview was to describe the clinical role of metal stents in nonva... more The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use. Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English. Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief. Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.
The Cleft Palate-Craniofacial Journal, Mar 1, 1992
Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A stu... more Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
The Cleft Palate-Craniofacial Journal, Mar 1, 1992
Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A stu... more Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
Objective: The main objectives for this evidence-based analysis were to determine the safety and ... more Objective: The main objectives for this evidence-based analysis were to determine the safety and effectiveness of photochemical corneal collagen cross-linking with riboflavin (vitamin B(2)) and ultraviolet-A radiation, referred to as CXL, for the management of corneal thinning disease conditions. The comparative safety and effectiveness of corneal cross-linking with other minimally invasive treatments such as intrastromal corneal rings was also reviewed. The Medical Advisory Secretariat (MAS) evidence-based analysis was performed to support public financing decisions. SUBJECT OF THE EVIDENCE-BASED ANALYSIS: The primary treatment objective for corneal cross-linking is to increase the strength of the corneal stroma, thereby stabilizing the underlying disease process. At the present time, it is the only procedure that treats the underlying disease condition. The proposed advantages for corneal cross-linking are that the procedure is minimally invasive, safe and effective, and it can potentially delay or defer the need for a corneal transplant. In addition, corneal cross-linking does not adversely affect subsequent surgical approaches, if they are necessary, or interfere with corneal transplants. The evidence for these claims for corneal cross-linking in the management of corneal thinning disorders such as keratoconus will be the focus of this review. The specific research questions for the evidence review were as follows: TECHNICAL: How technically demanding is corneal cross-linking and what are the operative risks? Safety: What is known about the broader safety profile of corneal cross-linking?Effectiveness - Corneal Surface Topographic Affects:What are the corneal surface remodeling effects of corneal cross-linking?Do these changes interfere with subsequent interventions, particularly corneal transplant known as penetrating keratoplasty (PKP)?Effectiveness -Visual Acuity:What impacts does the remodeling have on visual acuity?Are these impacts predictable, stable, adjustable and durable?Effectiveness - Refractive Outcomes: What impact does remodeling have on refractive outcomes?Effectiveness - Visual Quality (Symptoms): What impact does corneal cross-linking have on vision quality such as contrast vision, and decreased visual symptoms (halos, fluctuating vision)?Effectiveness - Contact lens tolerance: To what extent does contact lens intolerance improve after corneal cross-linking?Vision-Related QOL: What is the impact of corneal cross-linking on functional visual rehabilitation and quality of life?PATIENT SATISFACTION: Are patients satisfied with their vision following the procedure?Disease Process:What impact does corneal cross-linking have on the underling corneal thinning disease process?Does corneal cross-linking delay or defer the need for a corneal transplant?What is the comparative safety and effectiveness of corneal cross-linking compared with other minimally invasive treatments for corneal ectasia such as intrastromal corneal rings? Clinical need: TARGET POPULATION AND CONDITION Corneal ectasia (thinning) disorders represent a range of disorders involving either primary disease conditions, such as keratoconus (KC) and pellucid marginal corneal degeneration, or secondary iatrogenic conditions, such as corneal thinning occurring after laser in situ keratomileusis (LASIK) refractive surgery. Corneal thinning is a disease that occurs when the normally round dome-shaped cornea progressively thins causing a cone-like bulge or forward protrusion in response to the normal pressure of the eye. The thinning occurs primarily in the stroma layers and is believed to be a breakdown in the collagen process. This bulging can lead to irregular astigmatism or shape of the cornea. Because the anterior part of the cornea is responsible for most of the focusing of the light on the retina, this can then result in loss of visual acuity. The reduced visual acuity can make even simple daily tasks, such as driving, watching television or reading, difficult to perform. Keratoconus is the most common form of corneal thinning disorder and involves a noninflammatory chronic disease process of progressive corneal thinning. Although the specific cause for the biomechanical alterations in the corneal stroma is unknown, there is a growing body of evidence suggesting that genetic factors may play an important role. Keratoconus is a rare disease (< 0.05% of the population) and is unique among chronic eye diseases because it has an early onset, with a median age of 25 years. Disease management for this condition follows a step-wise approach depending on disease severity. Contact lenses are the primary treatment of choice when there is irregular astigmatism associated with the disease. Patients are referred for corneal transplants as a last option when they can no longer tolerate contact lenses or when lenses no longer provide adequate vision. Keratoconus is one of the leading indications for corneal transplants and has been so for the last 3 decades. Despite the high success rate of corneal transplants (up to 20 years) there are reasons to defer it as long as possible. Patients with keratoconus are generally young and a longer-term graft survival of at least 30 or 40 years may be necessary. The surgery itself involves lengthy time off work and postsurgery, while potential complications include long-term steroid use, secondary cataracts, and glaucoma. After a corneal transplant, keratoconus may recur resulting in a need for subsequent interventions. Residual refractive errors and astigmatism can remain challenges after transplantation, and high refractive surgery and regraft rates in KC patients have been reported. Visual rehabilitation or recovery of visual acuity after transplant may be slow and/or unsatisfactory to patients. Description of technology/therapy: Corneal cross-linking involves the use of riboflavin (vitamin B(2)) and ultraviolet-A (UVA) radiation. A UVA irradiation device known as the CXL® device (license number 77989) by ACCUTECH Medical Technologies Inc. has been licensed by Health Canada as a Class II device since September 19, 2008. An illumination device that emits homogeneous UVA, in combination with any generic form of riboflavin, is licensed by Health Canada for the indication to slow or stop the progression of corneal thinning caused by progressive keratectasia, iatrogenic keratectasia after laser-assisted in situ keratomileusis (LASIK) and pellucid marginal degeneration. The same device is named the UV-X® device by IROCMedical, with approvals in Argentina, the European Union and Australia. UVA devices all use light emitting diodes to generate UVA at a wavelength of 360-380 microns but vary in the number of diodes (5 to 25), focusing systems, working distance, beam diameter, beam uniformity and extent to which the operator can vary the parameters. In Ontario, CXL is currently offered at over 15 private eye clinics by refractive surgeons and ophthalmologists. The treatment is an outpatient procedure generally performed with topical anesthesia. The treatment consists of several well defined procedures. The epithelial cell layer is first removed, often using a blunt spatula in a 9.0 mm diameter under sterile conditions. This step is followed by the application of topical 0.1% riboflavin (vitamin B(2)) solution every 3 to 5 minutes for 25 minutes to ensure that the corneal stroma is fully penetrated. A solid-state UVA light source with a wavelength of 370 nm (maximum absorption of riboflavin) and an irradiance of 3 mW/cm(2) is used to irradiate the central cornea. Following treatment, a soft bandage lens is applied and prescriptions are given for oral pain medications, preservative-free tears, anti-inflammatory drops (preferably not nonsteroidal anti-inflammatory drugs, or NSAIDs) and antibiotic eye drops. Patients are recalled 1 week following the procedure to evaluate re-epithelialization and they are followed-up subsequently. Evidence-based analysis methods: A literature search was conducted on photochemical corneal collagen cross-linking with riboflavin (vitamin B(2)) and ultraviolet-A for the management of corneal thinning disorders using a search strategy with appropriate keywords and subject headings for CXL for literature published up until April 17, 2011. The literature search for this Health Technology Assessment (HTA) review was performed using the Cochrane Library, the Emergency Care Research Institute (ECRI) and the Centre for Reviews and Dissemination. The websites of several other health technology agencies were also reviewed, including the Canadian Agency for Drugs and Technologies in Health (CADTH) and the United Kingdom's National Institute for Clinical Excellence (NICE). The databases searched included OVID MEDLINE, MEDLINE IN-Process and other Non-Indexed Citations such as EMBASE. As the evidence review included an intervention for a rare condition, case series and case reports, particularly for complications and adverse events, were reviewed. A total of 316 citations were identified and all abstracts were reviewed by a single reviewer for eligibility. For those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. (ABSTRACT TRUNCATED)
ABSTRACT Computed tomography (CT) is a useful modality for the management of craniofacial anomali... more ABSTRACT Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.
BACKGROUND CONTEXT Osteoporotic vertebral fractures (OVF) dramatically increase with age and are ... more BACKGROUND CONTEXT Osteoporotic vertebral fractures (OVF) dramatically increase with age and are serious life altering adverse events for seniors resulting in increased rates of institutionalization, morbidity and mortality. Given the expanding population of the elderly and increasing prevalence of OVFs, cost-effective treatment strategies need to be considered. Percutaneous vertebral augmentation (VA) procedures such as vertebroplasty (VP) or balloon kyphoplasty (BK) are increasingly employed to treat painful vertebral fractures not responding to conservative management (CM) of bedrest and analgesia. Both VA procedures have been shown to be effective treatments for OVFs in multiple systematic reviews of randomized controlled trials. In this systematic review, analytical strategies, designs and results were compared for health economic studies evaluating cost-effectiveness of VA procedures, VP or BK for OVFs. Furthermore, assessments of quality (risk of bias) were conducted for the systematic review and the individual studies with peer-reviewed checklists recommended for cost-effectiveness studies. PURPOSE To provide an up-to-date systematic review of peer-reviewed studies evaluating cost-effectiveness of VA procedures, VP or KP for OVFs to support treatment and healthcare funding decisions. STUDY DESIGN This study is a systematic literature review and structured narrative synthesis. STUDY SAMPLE Peer reviewed health economic studies reporting cost-effectiveness for VA procedures, VP or BK for OVFs OUTCOME MEASURES: The following information extracted from the studies included: report country and year, study design, comparators, population, perspective, health valuations, costing sources and cost-effectiveness measures. For economic studies involving modeling, information was also extracted for model type, time horizon, key model drivers, and handling of uncertainty. Incremental cost-effectiveness ratio (ICER), the ratio of differences between comparator treatment groups in costs and health benefits, was considered the main cost-effectiveness measure. METHODS A systematic review was conducted of MEDLINE, EMBASE, CINAHL, ECONLIT, Cochrane Library and DARE databases up to the review date May 2021. Studies were reviewed for those reporting cost-effectiveness analyses on VA procedures including VP or BK for OVFs. Studies including only costs, abstracts, editorials, methodologies and reviews were not included. The selection of articles was reported in line with PRISMA guidance. A descriptive framework was developed to classify types of cost-effectiveness studies based on methodological differences and a structured narrative synthesis was used to summarize studies. Quality assessments were made with British Medical Journal checklist for individual cost-effectiveness studies and the CiCERO checklist for systematic reviews of cost-effectiveness studies. RESULTS In this systematic review, 520 references were identified through database searching and 501 were excluded as ineligible by titles and abstract based on prior eligibility criteria. From full-text reviews of 19 reports, ten were identified as eligible for the systematic review evaluating cost-effectiveness of VA procedures for OVFs. All references were published between 2008 and 2020. The ten cost-effectiveness studies, three for VP, three for BK and four for both VP and BK, all involved CM for OVFs as a treatment comparator. The studies involved different methods of economic analysis, modeling assumptions, cost and health valuations conducted in different healthcare setting over different time periods. A framework for the review outlines key features of cost-effectiveness study designs consisting of unmatched, matched, or randomized controls involving cost-effectiveness (CEA) or cost-utility (CUA)) analyses. Both VP and BK were cost-effective alternatives to CM for OVFs with earlier health gains and significantly shorter hospital stays. Cost-effectiveness estimates, ICERs, remained relatively stable and within willingness-to-pay thresholds under a range of sensitivity analyses. Comparisons between VP and BK were variable depending on modeling assumptions, but generally the procedures had similar health benefit gains with VP having lower acute procedural costs. CONCLUSIONS Both VP and BK, have been shown to be cost-effective alternatives to CM for osteoporotic vertebral fractures in diverse cost-effectiveness studies conducted in multiple healthcare settings. Trial-based CUA contributed the strongest evidence supporting cost-effectiveness determination for VP and BK for OVFs.
ObjectiveAlthough there is substantial clinical evidence on the safety and effectiveness of verte... more ObjectiveAlthough there is substantial clinical evidence on the safety and effectiveness of vertebral augmentation for osteoporotic vertebral fractures, cost-effectiveness is less well known. The objective of this study is to provide a systematic review of cost-effectiveness studies and policy-based willingness-to-pay (WTP) thresholds for different vertebral augmentation (VA) procedures, vertebroplasty (VP) and balloon kyphoplasty (BK), for osteoporotic vertebral fractures (OVFs).DesignA systematic review targeting cost-effectiveness studies of VA procedures for OVFs.Data sourcesSix bibliographic databases were searched from inception up to May 2021.Eligibility criteria for study selectionStudies were eligible if meeting all predefined criteria: (1) VP or BK intervention, (2) OVFs and (3) cost-effectiveness study. Articles not written in English, abstracts, editorials, reviews and those reporting only cost data were excluded.Data extraction and synthesisInformation was extracted on study characteristics, cost-effective estimates, summary decisions and payer WTP thresholds. Incremental cost-effective ratio (ICER) was the main outcome measure. Studies were summarised by a structured narrative synthesis organised by comparisons with conservative management (CM). Two independent reviewers assessed the quality (risk of bias) of the systematic review and cost-effectiveness studies by peer-reviewed checklists.ResultsWe identified 520 references through database searching and 501 were excluded as ineligible by titles and abstract. Ten reports were identified as eligible from 19 full-text reviews. ICER for VP versus CM evaluated as cost per quality-adjusted life-year (QALY) ranged from €22 685 (*US$33 395) in Netherlands to £−2240 (*US$−3273), a cost-saving in the UK. ICERs for BK versus CM ranged from £2706 (*US$3954) in UK to kr600 000 (*US$90 910) in Sweden. ICERs were within payer WTP thresholds for a QALY based on historical benchmarks.ConclusionsBoth VP and BK were judged cost-effective alternatives to CM for OVFs in economic studies and were within WTP thresholds in multiple healthcare settings.
Background: New anti-angiogenesis pharmacotherapies have dramatically altered treatment of age-re... more Background: New anti-angiogenesis pharmacotherapies have dramatically altered treatment of age-related macular degeneration (AMD), the leading cause of blindness in older adults. Monthly intraocular injections however, are extremely burdensome to ophthalmologists, patients, and their families. Repeated injections also increase risks of complications or adverse events. Although the pharmacokinetics of anti-vascular endothelial growth factor (A-VEGF) drugs are fairly well known, an individuals' AMD presentation and their pharmacodynamics or response to the drug has been shown to be extremely variable. Therefore treating everyone on the same fixed or standard regimen has potential for undertreating or overtreating patients, and drug costs are not trivial. Objectives: To review monitoring strategies and to evaluate the role of optical coherence tomography (OCT) in guiding management of A-VEGF-treated neovascular AMD (n-AMD) patients. Data sources: Systematic reviews of biographic databases for studies published between 2008 and February 2013 involving A-VEGF-treated n-AMD patients monitored in longitudinal follow-up. Review methods: Studies were grouped according to varying treatments, monitoring schedules, and re-treatment protocols reported for n-AMD patients treated with A-VEGF. Several outcomes were evaluated across strategies including visual acuity (VA), retinal anatomy, re-treatment criteria and frequencies of clinical follow-up, OCT imaging investigations, and intravitreal injections. Results were summarized qualitatively, as heterogeneity in study objectives and methods precluded formal meta-analysis. Results: A systematic review identified 18 randomized controlled trials (RCTs) and 20 observational studies involving A-VEGF treatment employing various monitoring and as-needed (PRN) re-treatment protocols. Several maintenance strategies were unsuccessful, resulting in lower VA gains and stabilization than monthly injections in A-VEGF-treated n-AMD. These included fixed quarterly treatment; fixed quarterly monitoring and PRN re-treatment; and monthly monitoring with either VA-guided re-treatment or quantitative-only VA/OCT- (central retinal thickness [CRT] > 100 μm) guided re-treatment. PRN re-treatment strategies with A-VEGF on the basis of monthly follow-up and rigorous reviews of OCT qualitative and quantitative measures of disease activity did decrease injection burden while maintaining visual gains. Gains in VA obtained with PRN re-treatment in usual clinical practice, however, were not as high as gains in clinical trials. Conclusions: To reduce treatment burden and provide a more individualized treatment strategy for n-AMD patients, OCT/VA-guided PRN treatment strategies have become the preferred and the dominant maintenance strategy. Success of these strategies, however, is dependent on close monitoring and adherence to tightly defined re-treatment criteria.
Background: Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and t... more Background: Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer in men and their second or third leading cause of cancer death. Prostate-specific antigen (PSA) testing for PC has been in common practice for more than 20 years. Objectives: A systematic review of the scientific literature was conducted to determine the effectiveness of PSA-based population screening programs for PC to inform policy decisions in a publicly funded health care system. Data sources: A systematic review of bibliographic databases was performed for systematic reviews or randomized controlled trials (RCT) of PSA-based population screening programs for PC. Review methods: A broad search strategy was employed to identify studies reporting on key outcomes of PC mortality and all-cause mortality. Results: The search identified 5 systematic reviews and 6 RCTs. None of the systematic reviews found a statistically significant reduction in relative risk (RR) of PC mortality or overall mortality with PSA-based screening. PC mortality reductions were found to vary by country, by screening program, and by age of men at study entry. The European Randomized Study of Screening for Prostate Cancer found a statistically significant reduction in RR in PC mortality at 11-year follow-up (0.79; 95% CI, 0.67-0.92), although the absolute risk reduction was small (1.0/10,000 person-years). However, the primary treatment for PCs differed significantly between countries and between trial arms. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) found a statistically non-significant increase in RR for PC mortality with 13-year follow-up (1.09; 95% CI, 0.87-1.36). The degree of opportunistic screening in the control arm of the PLCO trial, however, was high. None of the RCTs found a reduction in all-cause mortality and all found a statistically significant increase in the detection of mainly low-risk, organ-confined PCs in the screening arm. Conclusions: There was no evidence of a PC mortality reduction in the American PLCO trial, which investigated a screening program in a setting where opportunistic screening was already common practice. Given that opportunistic PSA screening practices in Canada are similar, it is unlikely that the introduction of a formal PSA screening program would reduce PC mortality.
Uploads
Papers by Gaylene Pron