BackgroundPrompt bystander cardiopulmonary resuscitation (CPR) is the single most important facto... more BackgroundPrompt bystander cardiopulmonary resuscitation (CPR) is the single most important factor determining survival from OHCA, increasing the likelihood of survival up to 4-fold. Much is invested in training lay-people to be competent but many don’t attempt CPR when they encounter OHCA reducing potential for emergency services interventions to be successful.AimTo develop a behaviour-change text-messaging intervention to increase proportion of lay-people who will initiate CPR in the event of OHCA.MethodsWorking with lay-people and expert advisory group we developed a series of 35 text messages comprising 14 behaviour change techniques designed to increase intentions to perform CPR. We recruited 20 lay people to a before and after pilot study to evaluate the acceptability of the messages and explore participant responses to them. Intention to perform CPR was assessed in relation to 4 varied scenarios before and after the intervention.ResultsTwenty lay-people (6F, 14M; aged 20-84) participated in the study. Seventeen received the complete intervention over 4-6 weeks, two received 20+messages and one a single message before opting out. Fifteen participants provided follow-up data. Intentions to initiate CPR in CPR scenarios were greater after the intervention than before with all but one participant maintaining or increasing their original (high) intentions. Increases in psychological predictors of intention: attitudes (pre:57.5 post:63.0), perceived behavioural control(pre:50.0 post:58.0), self-efficacy (pre:74.5 post:81.0) and self-assessed competence (pre:19.5 post:20.5) were observed following the intervention. Qualitative data suggested the intervention was positively received and viewed as helpful in improving confidence by reinforcing and building on messages from training though additional options for delivery format and pace should be considered.ConclusionsA behaviour-change text-message intervention delivered after CPR training is acceptable, easily scalable and may help improve rates of lay CPR initiation. Full scale evaluation of effectiveness is planned.
BACKGROUND Mathematical optimization can be used to place automated external defibrillators (AEDs... more BACKGROUND Mathematical optimization can be used to place automated external defibrillators (AEDs) in locations that maximize coverage of out-of-hospital cardiac arrests (OHCAs). We sought to determine whether optimization can improve alignment between AED locations and OHCA counts across levels of socioeconomic deprivation. METHODS All suspected OHCAs and registered AEDs in Scotland between Jan. 2011 - Sept. 2017 were included and mapped to a corresponding socioeconomic deprivation level using the Scottish Index of Multiple Deprivation (SIMD). We used mathematical optimization to determine optimal locations for placing 10%, 25%, 50%, and 100% additional AEDs, as well as locations for relocating existing AEDs. For each AED placement policy, we examined the impact on AED distribution and OHCA "coverage" (suspected OHCA occurring within 100m of AED) with respect to SIMD quintiles. RESULTS We identified 49,432 suspected OHCAs and 1,532 AEDs. The distribution of existing AED locations across SIMD quintiles significantly differed from the distribution of suspected OHCAs (P<0.001). Optimization-guided AED placement increased coverage of suspected OHCAs compared to existing AED locations (all P<0.001). Optimization resulted in more AED placements and increased OHCA coverage in areas of greater socioeconomic deprivation, such that resulting distributions across SIMD quintiles matched the shape of the OHCA count distribution. Optimally relocating existing AEDs achieved similar OHCA coverage levels to that of doubling the number of total AEDs. CONCLUSIONS Mathematical optimization results in AED locations and suspected OHCA coverage that more closely resembles the suspected OHCA distribution and results in more equitable coverage across levels of socioeconomic deprivation.
Journal of the American College of Emergency Physicians Open, Apr 29, 2023
The current literature on sex differences in 30‐day survival following out‐of‐hospital cardiac ar... more The current literature on sex differences in 30‐day survival following out‐of‐hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta‐analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population‐based studies and through separate meta‐analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex‐specific 30‐day survival or survival until hospital discharge after OHCA. Two meta‐analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22–1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84–1.03). Both meta‐analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non‐selected populations.
BackgroundTelephone-assisted CPR (t-CPR), where ambulance-service call-handlers provide instructi... more BackgroundTelephone-assisted CPR (t-CPR), where ambulance-service call-handlers provide instructions to callers on how to perform CPR, increases rates of CPR and survival. However, up to 1/3 of bystanders do not deliver CPR even when provided instructions. If the proportion of people who initiate CPR could be increased, lives would be saved. As a part of a larger project aimed at increasing rates of CPR, we conducted a qualitative study to identify call-handlers’ perceptions of the main barriers to CPR and what they think helps people to initiate CPR.MethodsSemi-structured qualitative interviews were conducted with 30 call-handlers from seven UK ambulance services, purposively selected to ensure diversity in terms of age, gender, years of experience, geographical location, population served (size/rurality), dispatch software used (MPDS and Pathways), published outcomes for ROSC and Care Quality Commission Rating.ResultsThirty call-handlers (19F, 10M, 1 non-binary; aged 22-59) participated. Participants had between 6mths and 25yrs experience and rated their confidence in providing CPR instructions between 3 and 10/10 (mean: 9). The barriers to CPR identified most commonly were the physical challenges of getting people flat on ground; the extreme emotional state of the caller and agonal breathing leading callers to believe that CPR was not required. Call-handlers described various techniques (some suggested by protocol and some not) used to encourage people to initiate/continue CPR. Data relating to the impact of pandemic-related pressures on call-handlers’ experiences of the role also emerged.ConclusionsProviding t-CPR instructions is a challenging but rewarding and valued aspect of call-handlers role. By synthesising the collective experience of a representative sample of call-handlers we have identified techniques used to overcome barriers to CPR initiation, many of which are consistent with behavioural theory. Additional opportunities to use behavioural techniques have been identified and will be developed in partnership with call-handlers.
Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main fu... more Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council Background Cardiopulmonary resuscitation (CPR) is the single most important factor determining survival from out of hospital cardiac arrest (OHCA). Even when trained, most lay-people don’t attempt CPR when they encounter OHCA. Working closely with intended users and CPR experts we developed a theory-based text-messaging intervention designed to increase rates of CPR. This pilot study was conducted to evaluate the acceptability of the messages, explore participant responses to them and to trial measures for a full evaluation. Design A before-and-after study plus qualitative interviews Methods Twenty lay-people from across Scotland agreed to take part and to receive the intervention (35 text-messages over approx. 6 weeks) At baseline and after participants had received intervention (approx. 6 weeks later) we measured how likely people were to perfo...
AIM of the review To examine global variation in the incidence and outcomes of emergency medical ... more AIM of the review To examine global variation in the incidence and outcomes of emergency medical services (EMS) witnessed out-of-hospital cardiac arrest (OHCA). Data sources We systematically reviewed four electronic databases for studies between 1990 and 5th April 2021 reporting EMS-witnessed OHCA populations. Studies were included if they reported sufficient data to calculate the primary outcome of survival to hospital discharge or 30-day survival. Random-effects models were used to pool incidence and survival outcomes, and meta-regression was used to examine sources of heterogeneity. Study quality was appraised using the Joanna Briggs Institute critical appraisal tools. RESULTS The search returned 1178 non-duplicate titles of which 66 articles comprising 133,981 EMS-witnessed patients treated by EMS across 33 countries were included. All but one study was observational and only 12 studies (18%) were deemed to be at low risk of bias. The pooled incidence of EMS-treated cases was 4.1 per 100,000 person-years (95% CI: 3.5, 4.7), varying almost 4-fold across continents. The pooled proportion of survivors to hospital discharge or 30-days was 20% overall (95% CI: 18%, 22%; I2 = 98%), 43% (95% CI: 37%, 49%; I2 = 94%) for initial shockable rhythms and 6% (95% CI: 5%, 8%; I2 = 79%) for initial non-shockable rhythms. In the meta-regression analysis, only region and aetiology were significantly associated with survival. When compared to studies from North America, pooled survival was significantly higher in studies from Europe (14% vs. 26%; p=0.04) and Australasia (14% vs. 31%, p<0.001). CONCLUSION We identified significant global variation in the incidence and survival outcome of EMS-witnessed OHCA. Further research is needed to understand the factors contributing to these variations.
BackgroundPrompt bystander cardiopulmonary resuscitation (CPR) is the single most important facto... more BackgroundPrompt bystander cardiopulmonary resuscitation (CPR) is the single most important factor determining survival from OHCA, increasing the likelihood of survival up to 4-fold. Much is invested in training lay-people to be competent but many don’t attempt CPR when they encounter OHCA reducing potential for emergency services interventions to be successful.AimTo develop a behaviour-change text-messaging intervention to increase proportion of lay-people who will initiate CPR in the event of OHCA.MethodsWorking with lay-people and expert advisory group we developed a series of 35 text messages comprising 14 behaviour change techniques designed to increase intentions to perform CPR. We recruited 20 lay people to a before and after pilot study to evaluate the acceptability of the messages and explore participant responses to them. Intention to perform CPR was assessed in relation to 4 varied scenarios before and after the intervention.ResultsTwenty lay-people (6F, 14M; aged 20-84) participated in the study. Seventeen received the complete intervention over 4-6 weeks, two received 20+messages and one a single message before opting out. Fifteen participants provided follow-up data. Intentions to initiate CPR in CPR scenarios were greater after the intervention than before with all but one participant maintaining or increasing their original (high) intentions. Increases in psychological predictors of intention: attitudes (pre:57.5 post:63.0), perceived behavioural control(pre:50.0 post:58.0), self-efficacy (pre:74.5 post:81.0) and self-assessed competence (pre:19.5 post:20.5) were observed following the intervention. Qualitative data suggested the intervention was positively received and viewed as helpful in improving confidence by reinforcing and building on messages from training though additional options for delivery format and pace should be considered.ConclusionsA behaviour-change text-message intervention delivered after CPR training is acceptable, easily scalable and may help improve rates of lay CPR initiation. Full scale evaluation of effectiveness is planned.
BACKGROUND Mathematical optimization can be used to place automated external defibrillators (AEDs... more BACKGROUND Mathematical optimization can be used to place automated external defibrillators (AEDs) in locations that maximize coverage of out-of-hospital cardiac arrests (OHCAs). We sought to determine whether optimization can improve alignment between AED locations and OHCA counts across levels of socioeconomic deprivation. METHODS All suspected OHCAs and registered AEDs in Scotland between Jan. 2011 - Sept. 2017 were included and mapped to a corresponding socioeconomic deprivation level using the Scottish Index of Multiple Deprivation (SIMD). We used mathematical optimization to determine optimal locations for placing 10%, 25%, 50%, and 100% additional AEDs, as well as locations for relocating existing AEDs. For each AED placement policy, we examined the impact on AED distribution and OHCA "coverage" (suspected OHCA occurring within 100m of AED) with respect to SIMD quintiles. RESULTS We identified 49,432 suspected OHCAs and 1,532 AEDs. The distribution of existing AED locations across SIMD quintiles significantly differed from the distribution of suspected OHCAs (P<0.001). Optimization-guided AED placement increased coverage of suspected OHCAs compared to existing AED locations (all P<0.001). Optimization resulted in more AED placements and increased OHCA coverage in areas of greater socioeconomic deprivation, such that resulting distributions across SIMD quintiles matched the shape of the OHCA count distribution. Optimally relocating existing AEDs achieved similar OHCA coverage levels to that of doubling the number of total AEDs. CONCLUSIONS Mathematical optimization results in AED locations and suspected OHCA coverage that more closely resembles the suspected OHCA distribution and results in more equitable coverage across levels of socioeconomic deprivation.
Journal of the American College of Emergency Physicians Open, Apr 29, 2023
The current literature on sex differences in 30‐day survival following out‐of‐hospital cardiac ar... more The current literature on sex differences in 30‐day survival following out‐of‐hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta‐analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population‐based studies and through separate meta‐analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex‐specific 30‐day survival or survival until hospital discharge after OHCA. Two meta‐analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22–1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84–1.03). Both meta‐analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non‐selected populations.
BackgroundTelephone-assisted CPR (t-CPR), where ambulance-service call-handlers provide instructi... more BackgroundTelephone-assisted CPR (t-CPR), where ambulance-service call-handlers provide instructions to callers on how to perform CPR, increases rates of CPR and survival. However, up to 1/3 of bystanders do not deliver CPR even when provided instructions. If the proportion of people who initiate CPR could be increased, lives would be saved. As a part of a larger project aimed at increasing rates of CPR, we conducted a qualitative study to identify call-handlers’ perceptions of the main barriers to CPR and what they think helps people to initiate CPR.MethodsSemi-structured qualitative interviews were conducted with 30 call-handlers from seven UK ambulance services, purposively selected to ensure diversity in terms of age, gender, years of experience, geographical location, population served (size/rurality), dispatch software used (MPDS and Pathways), published outcomes for ROSC and Care Quality Commission Rating.ResultsThirty call-handlers (19F, 10M, 1 non-binary; aged 22-59) participated. Participants had between 6mths and 25yrs experience and rated their confidence in providing CPR instructions between 3 and 10/10 (mean: 9). The barriers to CPR identified most commonly were the physical challenges of getting people flat on ground; the extreme emotional state of the caller and agonal breathing leading callers to believe that CPR was not required. Call-handlers described various techniques (some suggested by protocol and some not) used to encourage people to initiate/continue CPR. Data relating to the impact of pandemic-related pressures on call-handlers’ experiences of the role also emerged.ConclusionsProviding t-CPR instructions is a challenging but rewarding and valued aspect of call-handlers role. By synthesising the collective experience of a representative sample of call-handlers we have identified techniques used to overcome barriers to CPR initiation, many of which are consistent with behavioural theory. Additional opportunities to use behavioural techniques have been identified and will be developed in partnership with call-handlers.
Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main fu... more Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council Background Cardiopulmonary resuscitation (CPR) is the single most important factor determining survival from out of hospital cardiac arrest (OHCA). Even when trained, most lay-people don’t attempt CPR when they encounter OHCA. Working closely with intended users and CPR experts we developed a theory-based text-messaging intervention designed to increase rates of CPR. This pilot study was conducted to evaluate the acceptability of the messages, explore participant responses to them and to trial measures for a full evaluation. Design A before-and-after study plus qualitative interviews Methods Twenty lay-people from across Scotland agreed to take part and to receive the intervention (35 text-messages over approx. 6 weeks) At baseline and after participants had received intervention (approx. 6 weeks later) we measured how likely people were to perfo...
AIM of the review To examine global variation in the incidence and outcomes of emergency medical ... more AIM of the review To examine global variation in the incidence and outcomes of emergency medical services (EMS) witnessed out-of-hospital cardiac arrest (OHCA). Data sources We systematically reviewed four electronic databases for studies between 1990 and 5th April 2021 reporting EMS-witnessed OHCA populations. Studies were included if they reported sufficient data to calculate the primary outcome of survival to hospital discharge or 30-day survival. Random-effects models were used to pool incidence and survival outcomes, and meta-regression was used to examine sources of heterogeneity. Study quality was appraised using the Joanna Briggs Institute critical appraisal tools. RESULTS The search returned 1178 non-duplicate titles of which 66 articles comprising 133,981 EMS-witnessed patients treated by EMS across 33 countries were included. All but one study was observational and only 12 studies (18%) were deemed to be at low risk of bias. The pooled incidence of EMS-treated cases was 4.1 per 100,000 person-years (95% CI: 3.5, 4.7), varying almost 4-fold across continents. The pooled proportion of survivors to hospital discharge or 30-days was 20% overall (95% CI: 18%, 22%; I2 = 98%), 43% (95% CI: 37%, 49%; I2 = 94%) for initial shockable rhythms and 6% (95% CI: 5%, 8%; I2 = 79%) for initial non-shockable rhythms. In the meta-regression analysis, only region and aetiology were significantly associated with survival. When compared to studies from North America, pooled survival was significantly higher in studies from Europe (14% vs. 26%; p=0.04) and Australasia (14% vs. 31%, p<0.001). CONCLUSION We identified significant global variation in the incidence and survival outcome of EMS-witnessed OHCA. Further research is needed to understand the factors contributing to these variations.
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Papers by Gareth Clegg