Sarah L. Hardoon

How much of the recent decline in the incidence of myocardial infarction in British men can be explained by changes in cardiovascular risk factors? Evidence from a prospective population-based study.

Background— The incidence of myocardial infarction (MI) in Britain has fallen markedly in recent years. Few studies have investigated the extent to which this decline can be explained by concurrent changes in major cardiovascular risk factors. Methods and Results— The British Regional Heart Study examined changes in cardiovascular risk factors and MI incidence over 25 years from 1978 in a cohort of 7735 men. During this time, the age-adjusted hazard of MI decreased by 3.8% (95% confidence interval 2.6% to 5.0%) per annum, which corresponds to a 62% decline over the 25 years. At the same time, after adjustment for age, cigarette smoking prevalence, mean systolic blood pressure, and mean non–high-density lipoprotein (HDL) cholesterol decreased, whereas mean HDL cholesterol, mean body mass index, and physical activity levels rose. No significant change occurred in alcohol consumption. The fall in cigarette smoking explained the greatest part of the decline in MI incidence (23%), followed by changes in blood pressure (13%), HDL cholesterol (12%), and non-HDL cholesterol (10%). In combination, 46% (approximate 95% confidence interval 23% to 164%) of the decline in MI could be explained by these risk factor changes. Physical activity and alcohol consumption had little influence, whereas the increase in body mass index would have produced a rise in MI risk. Conclusions— Modest favorable changes in the major cardiovascular risk factors appear to have contributed to considerable reductions in MI incidence. This highlights the potential value of population-wide measures to reduce exposure to these risk factors in the prevention of coronary heart disease.

Explaining variation in referral from primary to secondary care: Cohort study

Objectives To determine the extent to which referral for defined symptoms from primary care varies by age, sex, and social deprivation and whether any sociodemographic variations in referral differ according to the presence of national referral guidance and the potential of the symptoms to be life threatening. Design Cohort study using individual patient data from the health improvement network database in primary care. Setting United Kingdom. Participants 5492 patients with postmenopausal bleeding, 23 121 with hip pain, and 101 212 with dyspepsia from 326 general practices, 2001-7. Main outcome measures Multivariable associations between odds of immediate referral for postmenopausal bleeding and age and social deprivation; hazard rates of referral for hip pain or dyspepsia and age, sex, and social deprivation. Analyses for dyspepsia were stratified for people aged less than and more than 55 years because referral guidance differs by age. Results 61.4% (3374/5492) of patients with postmenopausal bleeding, 17.4% (4019/23 121) with hip pain, and 13.8% (13 944/101 212) with dyspepsia were referred. The likelihood of referral for postmenopausal bleeding declined with increasing age: the adjusted odds ratio for patients aged 85 or more compared with those aged 55-64 was 0.39 (95% confidence interval 0.31 to 0.49). Patients aged 85 or more with hip pain were also less likely to be referred than those aged 55-64 (0.68, 0.57 to 0.81). Women were less likely than men to be referred for hip pain (hazard ratio 0.90, 95% confidence interval 0.84 to 0.96). More deprived patients with hip pain or dyspepsia (if aged <55) were less likely to be referred. Adjusted hazard ratios for those in the most deprived Townsend fifth compared with the least deprived were 0.72 (95% confidence interval 0.62 to 0.82) and 0.76 (0.68 to 0.85), respectively. No socioeconomic gradient was evident in referral for postmenopausal bleeding. Conclusions Inequalities in referral associated with socioeconomic circumstances were more likely to occur in the absence of both explicit guidance and potentially life threatening conditions, whereas inequalities with age were evident for all conditions.

Cardiovascular risk prediction models for people with severe mental illness: results from the prediction and management of cardiovascular risk in people with severe mental illnesses (PRIMROSE) research program

IMPORTANCE People with severe mental illness (SMI), including schizophrenia and bipolar disorder, have excess rates of cardiovascular disease (CVD). Risk prediction models validated for the general population may not accurately estimate cardiovascular risk in this group. OBJECTIVE To develop and validate a risk model exclusive to predicting CVD events in people with SMI incorporating established cardiovascular risk factors and additional variables. DESIGN, SETTING, AND PARTICIPANTS We used anonymous/deidentified data collected between January 1, 1995, and December 31, 2010, from the Health Improvement Network (THIN) to conduct a primary care, prospective cohort and risk score development study in the United Kingdom. Participants included 38,824 people with a diagnosis of SMI (schizophrenia, bipolar disorder, or other nonorganic psychosis) aged 30 to 90 years. During a median follow-up of 5.6 years, 2324 CVD events (6.0%) occurred. MAIN OUTCOMES AND MEASURES Ten-year risk of the first cardiovascular event (myocardial infarction, angina pectoris, cerebrovascular accidents, or major coronary surgery). Predictors included age, sex, height, weight, systolic blood pressure, diabetes mellitus, smoking, body mass index (BMI), lipid profile, social deprivation, SMI diagnosis, prescriptions for antidepressants and antipsychotics, and reports of heavy alcohol use. RESULTS We developed 2 CVD risk prediction models for people with SMI: the PRIMROSE BMI model and the PRIMROSE lipid model. These models mutually excluded lipids and BMI. In terms of discrimination, from cross-validations for men, the PRIMROSE lipid model D statistic was 1.92 (95% CI, 1.80-2.03) and C statistic was 0.80 (95% CI, 0.76-0.83) compared with 1.74 (95% CI, 1.63-1.86) and 0.78 (95% CI, 0.75-0.82) for published Cox Framingham risk scores. The corresponding results in women were 1.87 (95% CI, 1.76-1.98) and 0.79 (95% CI, 0.76-0.82) for the PRIMROSE lipid model and 1.58 (95% CI, 1.48-1.68) and 0.77 (95% CI, 0.73-0.81) for the Cox Framingham model. Discrimination statistics for the PRIMROSE BMI model were comparable to those for the PRIMROSE lipid model. Calibration plots suggested that both PRIMROSE models were superior to the Cox Framingham models. CONCLUSIONS AND RELEVANCE The PRIMROSE BMI and lipid CVD risk prediction models performed better in SMI compared with models that include only established CVD risk factors. Further work on the clinical effectiveness and cost-effectiveness of the PRIMROSE models is needed to ascertain the best thresholds for offering CVD interventions.

Sociodemographic variations in the contribution of secondary drug prevention to stroke survival at middle and older ages: cohort study.

Objectives To determine the extent to which secondary drug prevention for patients with stroke in routine primary care varies by sex, age, and socioeconomic circumstances, and to quantify the effect of secondary drug prevention on one year mortality by sociodemographic group. Design Cohort study using individual patient data from the health improvement network primary care database. Setting England. Participants 12 830 patients aged 50 or more years from 113 general practices who had a stroke between 1995 and 2005 and who survived the first 30 days after the stroke. Main outcome measures Multivariable associations between odds of receiving secondary prevention after a stroke, and sex, age group, and socioeconomic circumstances; hazard ratios for all cause mortality from 31 days after the stroke and within the first year among patients receiving treatment and by social group; and probabilities of one year mortality for social factors of interest and treatment. Results Only 25.6% of men and 20.8% of women received secondary prevention. Receipt of secondary prevention did not vary by socioeconomic circumstances or by sex. Older patients were, however, substantially less likely to receive treatment. The adjusted odds ratio for 80-89 year olds compared with 50-59 year olds was 0.53 (95% confidence interval 0.41 to 0.69). This was because older people were less likely to receive lipid lowering drugs—for example, the adjusted odds ratio for 80-89 year olds compared with 50-59 year olds was 0.44 (95% confidence interval 0.33 to 0.59). Secondary prevention was associated with a 50% reduction in mortality risk (adjusted hazard ratio 0.50, 95% confidence interval 0.42 to 59). On average, mortality within the first year was 5.7% for patients receiving treatment compared with 11.1% for patients not receiving treatment. There was little evidence that the effect of treatment differed between the social groups examined. Conclusion Under-treatment among older people with stroke in routine primary care cannot be justified given the lack of evidence on variations in effectiveness of treatment by age.

Recording of Severe Mental Illness in United Kingdom Primary Care, 2000–2010

Background There is increasing emphasis on primary care services for individuals with severe mental illnesses (SMI), including schizophrenia, bipolar disorder, and other non-organic psychotic disorders. However we lack information on how many people receive these different diagnoses in primary care. Primary care databases offer an opportunity to explore the recording of new SMI diagnoses in representative general practices. Methods We used data from The UK Health Improvement Network (THIN) primary care database including longitudinal patient records for individuals aged over 16 years from 437 general practices. We determined the annual GP recorded rate of first diagnosis of SMI by age, gender, social deprivation and urbanicity between 2000 and 2010. Results We identified 10,520 individuals with a first record of schizophrenia, bipolar disorder or other non-organic psychosis among 4,164,794 patients. This corresponded to a rate of first diagnosis of 46.4 per 100,000 person years at risk (PYAR) (95% CI 45.4 to 47.4) in the 16–65 age group. The rate of first record of schizophrenia was 9.2 per 100,000 PYAR (95% CI 8.7 to 9.6) in this age group, bipolar disorder was 15.0 per 100,000 PYAR (95% CI 14.4 to 15.5) and other non-organic psychotic disorder was 22.3 per 100,000 PYAR (95% CI 21.6 to 23.0). Conclusions The rates of GP recorded SMI in primary care records were broadly comparable to incidence rates from previous epidemiological studies of SMI and show similar patterns by socio-demographic characteristics. However there were some differences by specific diagnoses. GPs may be recording rates that are higher than those used to commission services.

Rising adiposity curbing decline in the incidence of myocardial infarction: 20-year follow-up of British men and women in the Whitehall II cohort

Aims To estimate the contribution of risk factor trends to 20-year declines in myocardial infarction (MI) incidence in British men and women. Methods and results From 1985 to 2004, 6379 men and 3074 women in the Whitehall II cohort were followed for incident MI and risk factor trends. Over 20 years, the age–sex-adjusted hazard of MI fell by 74% (95% confidence interval 48–87%), corresponding to an average annual decline of 6.5% (3.2–9.7%). Thirty-four per cent (20–76%) of the decline in MI hazard could be statistically explained by declining non-HDL cholesterol levels, followed by increased HDL cholesterol (17%, 10–32%), reduced systolic blood pressure (13%, 7–24%), and reduced cigarette smoking prevalence (6%, 2–14%). Increased fruit and vegetable consumption made a non-significant contribution of 7% (−1–20%). In combination, these five risk factors explained 56% (34–112%). Rising body mass index (BMI) was counterproductive, reducing the scale of the decline by 11% (5–23%) in isolation. The MI decline and the impact of the risk factors appeared similar for men and women. Conclusion In men and women, over half of the decline in MI risk could be accounted for by favourable risk factor time trends. The adverse role of BMI emphasizes the importance of addressing the rising population BMI.

Trends in longer-term survival following an acute myocardial infarction and prescribing of evidenced-based medications in primary care in the UK from 1991: a longitudinal population-based study

Background Both the incidence of myocardial infarction (MI) and short-term case fatality have declined in the UK. However, little is known about trends in longer-term survival following an MI. The aim of the study was to investigate trends in longer-term survival, alongside trends in medication prescribing in primary care. Methods Data came from 218 general practices contributing to the Health Improvement Network, a UK-wide primary care database. 3-year survival and medication use were determined for 6586 men and 3766 women who had an MI between 1991 and 2002 and had already survived 3 months. Results Adjusting for age and gender, the 3-year post-MI case-fatality rate among 3-month survivors fell by 28% (95% CI 13 to 40), from 83 deaths per 1000 person-years for MI occurring in 1991–2 to 61 deaths per 1000 person-years for MI in 2001–2. Relative declines in the case-fatality rate of 37% (20 to 50) and 14% (−11 to 34) were observed for men and women, respectively (p=0.06 for interaction). Prescribing in the 3 months following the MI of lipid-regulating drugs increased from 3% of patients in 1991 to 79% in 2002, prescribing of beta-blockers increased from 26% to 68%, prescribing of ACE inhibitors increased from 11% to 71% and prescribing of anti-platelet medication increased from 46% to 86%. Conclusion There has been a moderate improvement in longer-term survival following an MI, distinct from improvements in short-term survival, although men may have benefited more than women. Increased medication prescribing in primary care may be a contributing factor.

Is the Recent Rise in Type 2 Diabetes Incidence From 1984 to 2007 Explained by the Trend in Increasing BMI?: Evidence from a prospective study of British men

OBJECTIVE To estimate the extent to which increasing BMI may explain the rise in type 2 diabetes incidence in British men from 1984 to 2007. RESEARCH DESIGN AND METHODS A representative cohort ratio of 6,460 British men was followed-up for type 2 diabetes incidence between 1984 (aged 45–65 years) and 2007 (aged 67–89 years). BMI was ascertained at regular intervals before and during the follow-up. RESULTS Between 1984–1992 and 1999–2007, the age-adjusted hazard of type 2 diabetes more than doubled (hazard ratio 2.33 [95% CI 1.75–3.10]). Mean BMI rose by 1.42 kg/m2 (95% CI 1.10–1.74) between 1984 and 1999; this could explain 26% (95% CI 17–38) of the type 2 diabetes increase. CONCLUSIONS An appreciable portion of the rise in type 2 diabetes can be attributed to BMI changes. A substantial portion remains unexplained, possibly associated with other determinants such as physical activity. This merits further research.

Is the recent rise in type 2 diabetes mellitus incidence from 1984 to 2007 explained by the trend in increasing body mass index? Evidence from a prospective study of British men.

OBJECTIVE To estimate the extent to which increasing BMI may explain the rise in type 2 diabetes incidence in British men from 1984 to 2007. RESEARCH DESIGN AND METHODS A representative cohort ratio of 6,460 British men was followed-up for type 2 diabetes incidence between 1984 (aged 45–65 years) and 2007 (aged 67–89 years). BMI was ascertained at regular intervals before and during the follow-up. RESULTS Between 1984–1992 and 1999–2007, the age-adjusted hazard of type 2 diabetes more than doubled (hazard ratio 2.33 [95% CI 1.75–3.10]). Mean BMI rose by 1.42 kg/m2 (95% CI 1.10–1.74) between 1984 and 1999; this could explain 26% (95% CI 17–38) of the type 2 diabetes increase. CONCLUSIONS An appreciable portion of the rise in type 2 diabetes can be attributed to BMI changes. A substantial portion remains unexplained, possibly associated with other determinants such as physical activity. This merits further research.

Evidence of an accelerating increase in prevalence of diagnosed Type 2 diabetes in British men, 1978-2005

Background  The prevalence of Type 2 diabetes is increasing worldwide; predictions suggest that the disease will reach epidemic proportions this century. This study aims to estimate the extent of the increase in prevalence of diagnosed Type 2 diabetes in British men between 1978 and 2005.