On the estimation of the effect of weight change on a health outcome using observational data, by utilising the target trial emulation framework.

BACKGROUND/OBJECTIVES: When studying the effect of weight change between two time points on a health outcome using observational data, two main problems arise initially (i) 'when is time zero?' and (ii) 'which confounders should we account for?' From the baseline date or the 1st follow-up (when the weight change can be measured)? Different methods have been previously used in the literature that carry different sources of bias and hence produce different results. METHODS: We utilised the target trial emulation framework and considered weight change as a hypothetical intervention. First, we used a simplified example from a hypothetical randomised trial where no modelling is required. Then we simulated data from an observational study where modelling is needed. We demonstrate the problems of each of these methods and suggest a strategy. INTERVENTIONS: weight loss/gain vs maintenance. RESULTS: The recommended method defines time-zero at enrolment, but adjustment for confounders (or exclusion of individuals based on levels of confounders) should be performed both at enrolment and the 1st follow-up. CONCLUSIONS: The implementation of our suggested method [adjusting for (or excluding based on) confounders measured both at baseline and the 1st follow-up] can help researchers attenuate bias by avoiding some common pitfalls. Other methods that have been widely used in the past to estimate the effect of weight change on a health outcome are more biased. However, two issues remain (i) the exposure is not well-defined as there are different ways of changing weight (however we tried to reduce this problem by excluding individuals who develop a chronic disease); and (ii) immortal time bias, which may be small if the time to first follow up is short.

Obesity during the COVID-19 pandemic: both cause of high risk and potential effect of lockdown? A population-based electronic health record study.

OBJECTIVES: Obesity is a modifiable risk factor for coronavirus disease 2019 (COVID-19)-related mortality. We estimated excess mortality in obesity, both 'direct', through infection, and 'indirect', through changes in health care, and also due to potential increasing obesity during lockdown. STUDY DESIGN: The study design of this study is a retrospective cohort study and causal inference methods. METHODS: In population-based electronic health records for 1,958,638 individuals in England, we estimated 1-year mortality risk ('direct' and 'indirect' effects) for obese individuals, incorporating (i) pre-COVID-19 risk by age, sex and comorbidities, (ii) population infection rate and (iii) relative impact on mortality (relative risk [RR]: 1.2, 1.5, 2.0 and 3.0). Using causal inference models, we estimated impact of change in body mass index (BMI) and physical activity during 3-month lockdown on 1-year incidence for high-risk conditions (cardiovascular diseases, diabetes, chronic obstructive pulmonary disease and chronic kidney disease), accounting for confounders. RESULTS: For severely obese individuals (3.5% at baseline), at 10% population infection rate, we estimated direct impact of 240 and 479 excess deaths in England at RR 1.5 and 2.0, respectively, and indirect effect of 383-767 excess deaths, assuming 40% and 80% will be affected at RR = 1.2. Owing to BMI change during the lockdown, we estimated that 97,755 (5.4%: normal weight to overweight, 5.0%: overweight to obese and 1.3%: obese to severely obese) to 434,104 individuals (15%: normal weight to overweight, 15%: overweight to obese and 6%: obese to severely obese) would be at higher risk for COVID-19 over one year. CONCLUSIONS: Prevention of obesity and promotion of physical activity are at least as important as physical isolation of severely obese individuals during the pandemic.

A national initiative in data science for health: an evaluation of the UK Farr Institute.

OBJECTIVE: To evaluate the extent to which the inter-institutional, inter-disciplinary mobilisation of data and skills in the Farr Institute contributed to establishing the emerging field of data science for health in the UK. DESIGN AND OUTCOME MEASURES: We evaluated evidence of six domains characterising a new field of science:defining central scientific challenges,demonstrating how the central challenges might be solved,creating novel interactions among groups of scientists,training new types of experts,re-organising universities,demonstrating impacts in society.We carried out citation, network and time trend analyses of publications, and a narrative review of infrastructure, methods and tools. SETTING: Four UK centres in London, North England, Scotland and Wales (23 university partners), 2013-2018. RESULTS: 1. The Farr Institute helped define a central scientific challenge publishing a research corpus, demonstrating insights from electronic health record (EHR) and administrative data at each stage of the translational cycle in 593 papers with at least one Farr Institute author affiliation on PubMed. 2. The Farr Institute offered some demonstrations of how these scientific challenges might be solved: it established the first four ISO27001 certified trusted research environments in the UK, and approved more than 1000 research users, published on 102 unique EHR and administrative data sources, although there was no clear evidence of an increase in novel, sustained record linkages. The Farr Institute established open platforms for the EHR phenotyping algorithms and validations (>70 diseases, CALIBER). Sample sizes showed some evidence of increase but remained less than 10% of the UK population in primary care-hospital care linked studies. 3.The Farr Institute created novel interactions among researchers: the co-author publication network expanded from 944 unique co-authors (based on 67 publications in the first 30 months) to 3839 unique co-authors (545 papers in the final 30 months). 4. Training expanded substantially with 3 new masters courses, training >400 people at masters, short-course and leadership level and 48 PhD students. 5. Universities reorganised with 4/5 Centres established 27 new faculty (tenured) positions, 3 new university institutes. 6. Emerging evidence of impacts included: > 3200 citations for the 10 most cited papers and Farr research informed eight practice-changing clinical guidelines and policies relevant to the health of millions of UK citizens. CONCLUSION: The Farr Institute played a major role in establishing and growing the field of data science for health in the UK, with some initial evidence of benefits for health and healthcare. The Farr Institute has now expanded into Health Data Research (HDR) UK but key challenges remain including, how to network such activities internationally.

Long-term excess mortality associated with diabetes following acute myocardial infarction: a population-based cohort study.

BACKGROUND: The long-term excess risk of death associated with diabetes following acute myocardial infarction is unknown. We determined the excess risk of death associated with diabetes among patients with ST-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) after adjustment for comorbidity, risk factors and cardiovascular treatments. METHODS: Nationwide population-based cohort (STEMI n=281 259 and NSTEMI n=422 661) using data from the UK acute myocardial infarction registry, MINAP, between 1 January 2003 and 30 June 2013. Age, sex, calendar year and country-specific mortality rates for the populace of England and Wales (n=56.9 million) were matched to cases of STEMI and NSTEMI. Flexible parametric survival models were used to calculate excess mortality rate ratios (EMRR) after multivariable adjustment. This study is registered at ClinicalTrials.gov (NCT02591576). RESULTS: Over 1.94 million person-years follow-up including 120 568 (17.1%) patients with diabetes, there were 187 875 (26.7%) deaths. Overall, unadjusted (all cause) mortality was higher among patients with than without diabetes (35.8% vs 25.3%). After adjustment for age, sex and year of acute myocardial infarction, diabetes was associated with a 72% and 67% excess risk of death following STEMI (EMRR 1.72, 95% CI 1.66 to 1.79) and NSTEMI (1.67, 1.63 to 1.71). Diabetes remained significantly associated with substantial excess mortality despite cumulative adjustment for comorbidity (EMRR 1.52, 95% CI 1.46 to 1.58 vs 1.45, 1.42 to 1.49), risk factors (1.50, 1.44 to 1.57 vs 1.33, 1.30 to 1.36) and cardiovascular treatments (1.56, 1.49 to 1.63 vs 1.39, 1.36 to 1.43). CONCLUSIONS: At index acute myocardial infarction, diabetes was common and associated with significant long-term excess mortality, over and above the effects of comorbidities, risk factors and cardiovascular treatments.

Geographic variation in the treatment of non-ST-segment myocardial infarction in the English National Health Service: a cohort study.

OBJECTIVES: To investigate geographic variation in guideline-indicated treatments for non-ST-elevation myocardial infarction (NSTEMI) in the English National Health Service (NHS). DESIGN: Cohort study using registry data from the Myocardial Ischaemia National Audit Project. SETTING: All Clinical Commissioning Groups (CCGs) (n=211) in the English NHS. PARTICIPANTS: 357 228 patients with NSTEMI between 1 January 2003 and 30 June 2013. MAIN OUTCOME MEASURE: Proportion of eligible NSTEMI who received all eligible guideline-indicated treatments (optimal care) according to the date of guideline publication. RESULTS: The proportion of NSTEMI who received optimal care was low (48 257/357 228; 13.5%) and varied between CCGs (median 12.8%, IQR 0.7-18.1%). The greatest geographic variation was for aldosterone antagonists (16.7%, 0.0-40.0%) and least for use of an ECG (96.7%, 92.5-98.7%). The highest rates of care were for acute aspirin (median 92.8%, IQR 88.6-97.1%), and aspirin (90.1%, 85.1-93.3%) and statins (86.4%, 82.3-91.2%) at hospital discharge. The lowest rates were for smoking cessation advice (median 11.6%, IQR 8.7-16.6%), dietary advice (32.4%, 23.9-41.7%) and the prescription of P2Y12 inhibitors (39.7%, 32.4-46.9%). After adjustment for case mix, nearly all (99.6%) of the variation was due to between-hospital differences (median 64.7%, IQR 57.4-70.0%; between-hospital variance: 1.92, 95% CI 1.51 to 2.44; interclass correlation 0.996, 95% CI 0.976 to 0.999). CONCLUSIONS: Across the English NHS, the optimal use of guideline-indicated treatments for NSTEMI was low. Variation in the use of specific treatments for NSTEMI was mostly explained by between-hospital differences in care. Performance-based commissioning may increase the use of NSTEMI treatments and, therefore, reduce premature cardiovascular deaths. TRIAL REGISTRATION NUMBER: NCT02436187.

Prolonged dual antiplatelet therapy in stable coronary disease: comparative observational study of benefits and harms in unselected versus trial populations.

OBJECTIVE:  To estimate the potential magnitude in unselected patients of the benefits and harms of prolonged dual antiplatelet therapy after acute myocardial infarction seen in selected patients with high risk characteristics in trials. DESIGN:  Observational population based cohort study. SETTING:  PEGASUS-TIMI-54 trial population and CALIBER (ClinicAl research using LInked Bespoke studies and Electronic health Records). PARTICIPANTS:  7238 patients who survived a year or more after acute myocardial infarction. INTERVENTIONS:  Prolonged dual antiplatelet therapy after acute myocardial infarction. MAIN OUTCOME MEASURES:  Recurrent acute myocardial infarction, stroke, or fatal cardiovascular disease. Fatal, severe, or intracranial bleeding. RESULTS:  1676/7238 (23.1%) patients met trial inclusion and exclusion criteria ("target" population). Compared with the placebo arm in the trial population, in the target population the median age was 12 years higher, there were more women (48.6% v 24.3%), and there was a substantially higher cumulative three year risk of both the primary (benefit) trial endpoint of recurrent acute myocardial infarction, stroke, or fatal cardiovascular disease (18.8% (95% confidence interval 16.3% to 21.8%) v 9.04%) and the primary (harm) endpoint of fatal, severe, or intracranial bleeding (3.0% (2.0% to 4.4%) v 1.26% (TIMI major bleeding)). Application of intention to treat relative risks from the trial (ticagrelor 60 mg daily arm) to CALIBER's target population showed an estimated 101 (95% confidence interval 87 to 117) ischaemic events prevented per 10 000 treated per year and an estimated 75 (50 to 110) excess fatal, severe, or intracranial bleeds caused per 10 000 patients treated per year. Generalisation from CALIBER's target subgroup to all 7238 real world patients who were stable at least one year after acute myocardial infarction showed similar three year risks of ischaemic events (17.2%, 16.0% to 18.5%), with an estimated 92 (86 to 99) events prevented per 10 000 patients treated per year, and similar three year risks of bleeding events (2.3%, 1.8% to 2.9%), with an estimated 58 (45 to 73) events caused per 10 000 patients treated per year. CONCLUSIONS:  This novel use of primary-secondary care linked electronic health records allows characterisation of "healthy trial participant" effects and confirms the potential absolute benefits and harms of dual antiplatelet therapy in representative patients a year or more after acute myocardial infarction.

Discussion of "Combining Health Data Uses to Ignite Health System Learning".

This article is part of a For-Discussion-Section of Methods of Information in Medicine about the paper "Combining Health Data Uses to Ignite Health System Learning" written by John D. Ainsworth and Iain E. Buchan [1]. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the paper of Ainsworth and Buchan. In subsequent issues the discussion can continue through letters to the editor. With these comments on the paper "Combining Health Data Uses to Ignite Health System Learning", written by John D. Ainsworth and Iain E. Buchan [1], the journal seeks to stimulate a broad discussion on new ways for combining data sources for the reuse of health data in order to identify new opportunities for health system learning. An international group of experts has been invited by the editor of Methods to comment on this paper. Each of the invited commentaries forms one section of this paper.

Mortality and missed opportunities along the pathway of care for ST-elevation myocardial infarction: a national cohort study.

AIMS: To examine the association between cumulative missed opportunities for care (CMOC) and mortality in patients with ST-elevation myocardial infarction (STEMI). METHODS: A cohort study of 112,286 STEMI patients discharged from hospital alive between January 2007 and December 2010, using data from the Myocardial Ischaemia National Audit Project (MINAP). A CMOC score was calculated for each patient and included: pre-hospital ECG, acute use of aspirin, timely reperfusion, prescription at hospital discharge of aspirin, thienopyridine inhibitor, ACE-inhibitor (or equivalent), HMG-CoA reductase inhibitor and ß-blocker, and referral for cardiac rehabilitation. Mixed-effects logistic regression models evaluated the effect of CMOC on risk-adjusted 30-day and 1-year mortality (RAMR). RESULTS: 44.5% of patients were ineligible for ≥1 care component. Of patients eligible for all nine components, 50.6% missed ≥1 opportunity. Pre-hospital ECG and timely reperfusion were most frequently missed, predicting further missed care at discharge (pre-hospital ECG incident rate ratio [95% CI]: 1.64 [1.58-1.70]; timely reperfusion 9.94 [9.51-10.40]). Patients ineligible for care had higher RAMR than those eligible for care (30-days: 1.7% vs. 1.1%; 1-year: 8.6% vs. 5.2%), whilst those with no missed care had lower mortality than patients with ≥4 CMOC (30-days: 0.5% vs. 5.4%, adjusted OR (aOR) per CMOC group 1.22, 95% CI: 1.05-1.42; 1-year: 3.2% vs. 22.8%, aOR 1.23, 1.13-1.34). CONCLUSIONS: Opportunities for care in STEMI are commonly missed and significantly associated with early and later mortality. Thus, outcomes after STEMI may be improved by greater attention to missed opportunities to eligible care.

International comparisons of the management of patients with non-ST segment elevation acute myocardial infarction in the United Kingdom, Sweden, and the United States: The MINAP/NICOR, SWEDEHEART/RIKS-HIA, and ACTION Registry-GWTG/NCDR registries.

OBJECTIVES: To compare management of patients with acute non-ST segment elevation myocardial infarction (NSTEMI) in three developed countries with national ongoing registries. BACKGROUND: Results from clinical trials suggest significant variation in care across the world. However, international comparisons in "real world" registries are limited. METHODS: We compared the use of in-hospital procedures and discharge medications for patients admitted with NSTEMI from 2007 to 2010 using the unselective MINAP/NICOR [England and Wales (UK); n=137,009], the unselective SWEDEHEART/RIKS-HIA (Sweden; n=45,069), and the selective ACTION Registry-GWTG/NCDR [United States (US); n=147,438] clinical registries. RESULTS: Patients enrolled among the three registries were generally similar except those in the US who were younger but had higher rates of smoking, diabetes, hypertension, prior heart failure, and prior MI than in Sweden or in UK. Angiography and percutaneous coronary intervention (PCI) were performed more often in the US (76% and 44%) and Sweden (65% and 42%) relative to the UK (32% and 22%). Discharge betablockers were also prescribed more often in the US (89%) and Sweden (89%) than in the UK (76%). In contrast, discharge statins, angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB), and dual antiplatelet agents (among those not receiving PCI) were higher in the UK (92%, 79%, and 71%) than in the US (85%, 65%, 41%) and Sweden (81%, 69%, and 49%). CONCLUSIONS: The care for patients with NSTEMI differed substantially among the three countries. These differences in care among countries provide an opportunity for future comparative effectiveness research as well as identify opportunities for global quality improvement.

Effect of ß blockers on mortality after myocardial infarction in adults with COPD: population based cohort study of UK electronic healthcare records.

OBJECTIVES: To investigate whether the use and timing of prescription of ß blockers in patients with chronic obstructive pulmonary disease (COPD) having a first myocardial infarction was associated with survival and to identify factors related to their use. DESIGN: Population based cohort study in England. SETTING: UK national registry of myocardial infarction (Myocardial Ischaemia National Audit Project (MINAP)) linked to the General Practice Research Database (GPRD), 2003-11. PARTICIPANTS: Patients with COPD with a first myocardial infarction in 1 January 2003 to 31 December 2008 as recorded in MINAP, who had no previous evidence of myocardial infarction in their GPRD or MINAP record. Data were provided by the Cardiovascular Disease Research using Linked Bespoke studies and Electronic Health Records (CALIBER) group at University College London. MAIN OUTCOME MEASURE: Cox proportional hazards ratio for mortality after myocardial infarction in patients with COPD in those prescribed ß blockers or not, corrected for covariates including age, sex, smoking status, drugs, comorbidities, type of myocardial infarction, and severity of infarct. RESULTS: Among 1063 patients with COPD, treatment with ß blockers started during the hospital admission for myocardial infarction was associated with substantial survival benefits (fully adjusted hazard ratio 0.50, 95% confidence interval 0.36 to 0.69; P<0.001; median follow-up time 2.9 years). Patients already taking a ß blocker before their myocardial infarction also had a survival benefit (0.59, 0.44 to 0.79; P<0.001). Similar results were obtained with propensity scores as an alternative method to adjust for differences between those prescribed and not prescribed ß blockers. With follow-up started from date of discharge from hospital, the effect size was slightly attenuated but there was a similar protective effect of treatment with ß blockers started during hospital admission for myocardial infarction (0.64, 0.44 to 0.94; P=0.02). CONCLUSIONS: The use of ß blockers started either at the time of hospital admission for myocardial infarction or before a myocardial infarction is associated with improved survival after myocardial infarction in patients with COPD. REGISTRATION: NCT01335672.

Incidence and prognosis of angina pectoris in South Asians and Whites: 18 years of follow-up over seven phases in the Whitehall-II prospective cohort study.

BACKGROUND: Whether the higher coronary mortality in South Asians compared with White populations is due to a higher incidence of disease is not known. This study assessed cumulative incidence of chest pain in South Asians and Whites, and prognosis of chest pain. METHODS: Over seven phases of 18-year follow-up of the Whitehall-II study (9,775 civil servants: 9,195 White, 580 South Asian), chest pain was assessed using the Rose questionnaire. Coronary death/non-fatal myocardial infarction was examined comparing those with chest pain to those with no chest pain at baseline. RESULTS: South Asians had higher cumulative frequencies of typical angina by Phase 7 (17.0 versus 11.3%, P < 0.001) and exertional chest pain (15.4 versus 8.5%, P < 0.001) compared with Whites. Typical angina and exertional chest pain at baseline were associated with a worse prognosis compared with those with no chest pain in both groups (typical angina, South Asians: HR, 4.67 and 95% CI, 2.12-0.30; Whites: HR, 3.56 95% CI, 2.59-4.88). Baseline non-exertional chest pain did not confer a worse prognosis. Across all types of pain, prognosis was worse in South Asians. CONCLUSION: South Asians had higher cumulative incidence of angina than Whites. In both, typical angina and exertional chest pain were associated with worse prognosis compared with those with no chest pain.

The effectiveness and cost-effectiveness of biomarkers for the prioritisation of patients awaiting coronary revascularisation: a systematic review and decision model.

OBJECTIVE: To determine the effectiveness and cost-effectiveness of a range of strategies based on conventional clinical information and novel circulating biomarkers for prioritising patients with stable angina awaiting coronary artery bypass grafting (CABG). DATA SOURCES: MEDLINE and EMBASE were searched from 1966 until 30 November 2008. REVIEW METHODS: We carried out systematic reviews and meta-analyses of literature-based estimates of the prognostic effects of circulating biomarkers in stable coronary disease. We assessed five routinely measured biomarkers and the eight emerging (i.e. not currently routinely measured) biomarkers recommended by the European Society of Cardiology Angina guidelines. The cost-effectiveness of prioritising patients on the waiting list for CABG using circulating biomarkers was compared against a range of alternative formal approaches to prioritisation as well as no formal prioritisation. A decision-analytic model was developed to synthesise data on a range of effectiveness, resource use and value parameters necessary to determine cost-effectiveness. A total of seven strategies was evaluated in the final model. RESULTS: We included 390 reports of biomarker effects in our review. The quality of individual study reports was variable, with evidence of small study (publication) bias and incomplete adjustment for simple clinical information such as age, sex, smoking, diabetes and obesity. The risk of cardiovascular events while on the waiting list for CABG was 3 per 10,000 patients per day within the first 90 days (184 events in 9935 patients with a mean of 59 days at risk). Risk factors associated with an increased risk, and included in the basic risk equation, were age, diabetes, heart failure, previous myocardial infarction and involvement of the left main coronary artery or three-vessel disease. The optimal strategy in terms of cost-effectiveness considerations was a prioritisation strategy employing biomarker information. Evaluating shorter maximum waiting times did not alter the conclusion that a prioritisation strategy with a risk score using estimated glomerular filtration rate (eGFR) was cost-effective. These results were robust to most alternative scenarios investigating other sources of uncertainty. However, the cost-effectiveness of the strategy using a risk score with both eGFR and C-reactive protein (CRP) was potentially sensitive to the cost of the CRP test itself (assumed to be 6 pounds in the base-case scenario). CONCLUSIONS: Formally employing more information in the prioritisation of patients awaiting CABG appears to be a cost-effective approach and may result in improved health outcomes. The most robust results relate to a strategy employing a risk score using conventional clinical information together with a single biomarker (eGFR). The additional prognostic information conferred by collecting the more costly novel circulating biomarker CRP, singly or in combination with other biomarkers, in terms of waiting list prioritisation is unlikely to be cost-effective.

Job strain and symptoms of angina pectoris among British and Finnish middle-aged employees.

BACKGROUND: High job strain has been linked with cardiovascular outcomes. This study aimed to examine whether job strain is associated with angina pectoris symptoms among British and Finnish non-manual employees. METHODS: Postal questionnaire survey data among 40-60-year-old employees of the British Whitehall II Study (n = 4551, 27% women) and the Finnish Helsinki Health Study (n = 7605, 83% women) cohort were analysed. Angina pectoris symptoms were the outcome in logistic regression analysis. Karasek's job strain was examined. Models were adjusted first for age, second for occupational class and finally for smoking, heavy drinking, physical inactivity, unhealthy food habits and obesity. RESULTS: Angina pectoris symptoms were reported by 5% of women and 3% of men in Britain, and by 6% of women and 4% of men in Finland. High job strain was associated with angina pectoris symptoms among men in Britain (OR 2.08; CI 95% 1.07 to 4.02) and women in Finland (OR 1.90; CI 95% 1.36 to 2.63) independent of age, occupational class, and behavioural risk factors. However, similar associations between job strain and angina pectoris symptoms were not observed among men in Finland or women in Britain. CONCLUSION: The results yielded partial support for the association between job strain and angina pectoris symptoms across national contexts.

Biological and behavioural explanations of social inequalities in coronary heart disease: the Whitehall II study.

AIMS/HYPOTHESIS: We determined the degree to which metabolic syndrome components, inflammation and health behaviours account for the social gradient in CHD. METHODS: A total of 5312 men, initially aged 39 to 63 years, were followed for 13.1 years for incident coronary death or non-fatal myocardial infarction according to socioeconomic position (employment grade). The contribution of explanatory factors to socioeconomic differences in CHD was assessed by the reduction in hazard ratios computed using Cox models. The effects of measurement error were taken into account. RESULTS: Coronary events were more common in lower employment grades than in higher, with a hazard ratio (relative index of inequality) of 2.2 (95% CI 1.3-3.7), after adjustment for age and ethnic group. Behavioural risk factors (mainly smoking and diet) explained a third of the socioeconomic gradient in CHD incidence. Components of the metabolic syndrome and inflammatory markers predicted CHD incidence and also explained a third of the gradient. Combined, these two groups of predictors, i.e. behavioural and biological, accounted for over half of the socioeconomic gradient in incident CHD. Adding body height as a marker of the effects of early life increased this figure to about 60%. CONCLUSIONS/INTERPRETATION: A major question has been how someone's socioeconomic position can lead to increased risk of CHD. Socioeconomic differences in components of the metabolic syndrome (and inflammatory markers) provide part of the answer. This was, to an important degree, independent of the contribution of health behaviours to the socioeconomic differentials in CHD.

Increased sickness absence in diabetic employees: what is the role of co-morbid conditions?

AIMS: Diabetes is thought to be associated with increased risk of sickness absence in working populations. We examined the contribution of co-morbidity to this association. METHODS: Records of physician-certified sickness absence episodes (> 3 days) over a 1-year period were obtained from employers' records after a survey of chronic diseases and risk factors in 638 diabetic and 32 510 non-diabetic public sector employees in Finland (the Public Sector Study). RESULTS: Diabetic employees had a 2.15-fold (95% confidence interval 1.92-2.40) age- and sex-adjusted excess risk of sickness absence compared with their colleagues with no chronic disease. In absolute terms, diabetes was related to 59 extra absence episodes per 100 person years. Of this excess risk, 55% was attributable to co-occurring non-cardiovascular diseases, such as depression, prolapsed intervertebral disc and bronchitis. The contribution of cardiovascular complications to the excess sickness absence was small (7%). CONCLUSIONS: In this occupational cohort, the excess risk of sickness absence in diabetic employees was largely accounted for by non-cardiovascular co-morbidity. Intervening multiple chronic conditions may be important in programmes to reduce sickness absence in diabetic employees.

Cost effectiveness of clinically appropriate decisions on alternative treatments for angina pectoris: prospective observational study.

OBJECTIVE: To assess whether revascularisation that is considered to be clinically appropriate is also cost effective. DESIGN: Prospective observational study comparing cost effectiveness of coronary artery bypass grafting, percutaneous coronary intervention, or medical management within groups of patients rated as appropriate for revascularisation. SETTING: Three tertiary care centres in London. PARTICIPANTS: Consecutive, unselected patients rated as clinically appropriate (using a nine member Delphi panel) to receive coronary artery bypass grafting only (n=815); percutaneous coronary intervention only (n=385); or both revascularisation procedures (n=520). MAIN OUTCOME MEASURE: Cost per quality adjusted life year gained over six year follow-up, calculated with a National Health Service cost perspective and discounted at 3.5%/year. RESULTS: Coronary artery bypass grafting cost 22,000 pounds sterling (33,000 euros; $43,000) per quality adjusted life year gained compared with percutaneous coronary intervention among patients appropriate for coronary artery bypass grafting only (59% probability of being cost effective at a cost effectiveness threshold of 30,000 pounds sterling per quality adjusted life year) and 19,000 pounds sterling per quality adjusted life year gained compared with medical management among those appropriate for both types of revascularisation (probability of being cost effective 63%). In none of the three appropriateness groups was percutaneous coronary intervention cost effective at a threshold of 30,000 pounds sterling per quality adjusted life year. Among patients rated appropriate for percutaneous coronary intervention only, the cost per quality adjusted life year gained for percutaneous coronary intervention compared with medical management was 47,000, pounds sterling exceeding usual cost effectiveness thresholds; in these patients, medical management was most likely to be cost effective (probability 54%). CONCLUSIONS: Among patients judged clinically appropriate for coronary revascularisation, coronary artery bypass grafting seemed cost effective but percutaneous coronary intervention did not. Cost effectiveness analysis based on observational data suggests that the clinical benefit of percutaneous coronary intervention may not be sufficient to justify its cost.

How effective are rapid access chest pain clinics? Prognosis of incident angina and non-cardiac chest pain in 8762 consecutive patients.

OBJECTIVE: To determine whether rapid access chest pain clinics are clinically effective by comparison of coronary event rates in patients diagnosed with angina with rates in patients diagnosed with non-cardiac chest pain and the general population. DESIGN: Multicentre cohort study of consecutive patients with chest pain attending the rapid access chest pain clinics (RACPCs) of six hospitals in England. PARTICIPANTS: 8762 patients diagnosed with either non-cardiac chest pain (n = 6396) or incident angina without prior myocardial infarction (n = 2366) at first cardiological assessment, followed up for a median of 2.57 (interquartile range 1.96-4.15) years. MAIN OUTCOME MEASURES: Primary end point--death due to coronary heart disease (International Classification of Diseases (ICD)10 I20-I25) or acute coronary syndrome (non-fatal myocardial infarction (ICD10 I21-I23), hospital admission with unstable angina (I24.0, I24.8, I24.9)). Secondary end points--all-cause mortality (ICD I20), cardiovascular death (ICD10 I00-I99), or non-fatal myocardial infarction or non-fatal stroke (I60-I69). RESULTS: The cumulative probability of the primary end point in patients diagnosed with angina was 16.52% (95% confidence interval (CI) 14.88% to 18.32%) after 3 years compared with 2.73% (95% CI 2.29% to 3.25%) in patients with non-cardiac chest pain. Coronary standardised mortality ratios for men and women with angina aged <65 years were 3.52 (95% CI 1.98 to 5.07) and 4.39 (95% CI 1.14 to 7.64). Of the 599 patients who had the primary end point, 194 (32.4%) had been diagnosed with non-cardiac chest pain. These patients were younger, less likely to have typical symptoms, more likely to be south Asian and more likely to have a normal resting electrocardiogram than patients with angina who had the primary end point. CONCLUSION: RACPCs are successful in identifying patients with incident angina who are at high coronary risk, but there is a need to reduce misdiagnosis and improve outcomes in patients diagnosed with non-cardiac chest pain who accounted for nearly one third of cardiac events during follow-up.

Rapid-access chest pain clinics and the traditional cardiology out-patient clinic.

BACKGROUND: The National Service Framework for coronary heart disease recommends rapid-access chest pain clinics (RACPCs) for cardiological assessment of new-onset chest pain within 2 weeks of referral. AIM: To measure the extent to which an RACPC successfully substituted for an out-patient cardiology clinic (OPCC) at a general hospital, in assessing new-onset chest pain referrals. METHODS: Prospective measurement of attendance and waiting times for consecutive patients at the RACPC and OPCC, and multivariate analysis of factors associated with referral for angiography. RESULTS: From September 2002 to August 2004, 1382 patients with chest pain attended the RACPC, and 228 patients, the OPCC. All RACPC patients were seen within 24 h of referral, except those referred on Friday afternoons, or the day before national holidays. The mean +/- SD waiting time for OPCC appointments was 97 +/- 43 days. Of 208 OPCC patients, 30 (14%) fulfilled the RACPC referral criterion of recent onset chest pain (<4 weeks duration) vs. 926/1382 (67%) RACPC patients. Thus the RACPC substituted for the OPCC in 926/956 (97%) new chest pain referrals. Patients from the OPCC were 3.82 (95%CI 1.85-7.90) more likely to be referred for a coronary angiogram. compared to those attending the RACPC. DISCUSSION: The RACPC has provided efficient and effective substitution for the OPCC in the assessment of new chest pain referrals according to pre-defined referral criteria. Broadening the referral criterion of the RACPC to patients with chest pain of >4 weeks duration would result in more referrals.

Is retirement good or bad for mental and physical health functioning? Whitehall II longitudinal study of civil servants.

BACKGROUND: To determine whether retirement at age 60 is associated with improvement or deterioration in mental and physical health, when analysed by occupational grade and gender. METHODS: Longitudinal study of civil servants aged 54 to 59 years at baseline, comparing changes in SF-36 health functioning in retired (n=392) and working (n=618) participants at follow up. Data were collected from self completed questionnaires. RESULTS: Mental health functioning deteriorated among those who continued to work, but improved among the retired. However, improvements in mental health were restricted to those in higher employment grades. Physical functioning declined in both working and retired civil servants. CONCLUSION: The study found that retirement at age 60 had no effects on physical health functioning and, if anything, was associated with an improvement in mental health, particularly among high socioeconomic status groups.

Population need for coronary revascularisation: are national targets for England credible?

OBJECTIVE: To estimate the need for coronary revascularisation, by using an incidence of indications approach, among 45-84 year olds with stable angina, unstable angina, and acute myocardial infarction. DESIGN: Modelling exercise. Six key steps along the pathway of care from initial diagnosis in primary or secondary care to revascularisation were defined and the frequency of indications estimated using routine data from hospital admissions and data from studies in the general population, and primary and secondary care. SETTING AND PATIENTS: Mid-1998 population of England. INTERVENTION: Coronary revascularisation. MAIN OUTCOME MEASURE: Ability to benefit (need), defined by randomised trials, expert panel ratings from the ACRE (appropriateness of coronary revascularisation) study, or by informal consensus. RESULTS: The need for coronary revascularisation was estimated to be 92 000 procedures, equivalent to a rate of 1861 per million population. Overall, the model of need exceeded current provision by 3.3:1, although among people aged 75 years and over the ratio was 7.7:1. A plausible upper estimate of need--obtained by assuming that 90% of patients with stable angina were referred from primary care and that angiography would be performed in 65% of patients with acute myocardial infarction and 75% of patients with unstable angina--was 2626 per million population. CONCLUSIONS: The national target of 1500 revascularisation procedures per million population is credibly related to population need, although upper estimates of need are considerably higher. Better understanding is required of the benefits of referring patients with specific indications from primary care. The greatest relative increase in provision is required for those aged 75 and older, among whom trial evidence of benefit is scant.