Narinder Bansal

Body-mass index and all-cause mortality: Individual-participant-data meta-analysis of 239 prospective studies in four continents.

Summary Background Overweight and obesity are increasing worldwide. To help assess their relevance to mortality in different populations we conducted individual-participant data meta-analyses of prospective studies of body-mass index (BMI), limiting confounding and reverse causality by restricting analyses to never-smokers and excluding pre-existing disease and the first 5 years of follow-up. Methods Of 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America from 239 prospective studies (median follow-up 13·7 years, IQR 11·4–14·7), 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died. The primary analyses are of these deaths, and study, age, and sex adjusted hazard ratios (HRs), relative to BMI 22·5–<25·0 kg/m2. Findings All-cause mortality was minimal at 20·0–25·0 kg/m2 (HR 1·00, 95% CI 0·98–1·02 for BMI 20·0–<22·5 kg/m2; 1·00, 0·99–1·01 for BMI 22·5–<25·0 kg/m2), and increased significantly both just below this range (1·13, 1·09–1·17 for BMI 18·5–<20·0 kg/m2; 1·51, 1·43–1·59 for BMI 15·0–<18·5) and throughout the overweight range (1·07, 1·07–1·08 for BMI 25·0–<27·5 kg/m2; 1·20, 1·18–1·22 for BMI 27·5–<30·0 kg/m2). The HR for obesity grade 1 (BMI 30·0–<35·0 kg/m2) was 1·45, 95% CI 1·41–1·48; the HR for obesity grade 2 (35·0–<40·0 kg/m2) was 1·94, 1·87–2·01; and the HR for obesity grade 3 (40·0–<60·0 kg/m2) was 2·76, 2·60–2·92. For BMI over 25·0 kg/m2, mortality increased approximately log-linearly with BMI; the HR per 5 kg/m2 units higher BMI was 1·39 (1·34–1·43) in Europe, 1·29 (1·26–1·32) in North America, 1·39 (1·34–1·44) in east Asia, and 1·31 (1·27–1·35) in Australia and New Zealand. This HR per 5 kg/m2 units higher BMI (for BMI over 25 kg/m2) was greater in younger than older people (1·52, 95% CI 1·47–1·56, for BMI measured at 35–49 years vs 1·21, 1·17–1·25, for BMI measured at 70–89 years; pheterogeneity<0·0001), greater in men than women (1·51, 1·46–1·56, vs 1·30, 1·26–1·33; pheterogeneity<0·0001), but similar in studies with self-reported and measured BMI. Interpretation The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in four continents. This finding supports strategies to combat the entire spectrum of excess adiposity in many populations. Funding UK Medical Research Council, British Heart Foundation, National Institute for Health Research, US National Institutes of Health.

Association of Cardiometabolic Multimorbidity With Mortality.

IMPORTANCE The prevalence of cardiometabolic multimorbidity is increasing. OBJECTIVE To estimate reductions in life expectancy associated with cardiometabolic multimorbidity. DESIGN, SETTING, AND PARTICIPANTS Age- and sex-adjusted mortality rates and hazard ratios (HRs) were calculated using individual participant data from the Emerging Risk Factors Collaboration (689,300 participants; 91 cohorts; years of baseline surveys: 1960-2007; latest mortality follow-up: April 2013; 128,843 deaths). The HRs from the Emerging Risk Factors Collaboration were compared with those from the UK Biobank (499,808 participants; years of baseline surveys: 2006-2010; latest mortality follow-up: November 2013; 7995 deaths). Cumulative survival was estimated by applying calculated age-specific HRs for mortality to contemporary US age-specific death rates. EXPOSURES A history of 2 or more of the following: diabetes mellitus, stroke, myocardial infarction (MI). MAIN OUTCOMES AND MEASURES All-cause mortality and estimated reductions in life expectancy. RESULTS In participants in the Emerging Risk Factors Collaboration without a history of diabetes, stroke, or MI at baseline (reference group), the all-cause mortality rate adjusted to the age of 60 years was 6.8 per 1000 person-years. Mortality rates per 1000 person-years were 15.6 in participants with a history of diabetes, 16.1 in those with stroke, 16.8 in those with MI, 32.0 in those with both diabetes and MI, 32.5 in those with both diabetes and stroke, 32.8 in those with both stroke and MI, and 59.5 in those with diabetes, stroke, and MI. Compared with the reference group, the HRs for all-cause mortality were 1.9 (95% CI, 1.8-2.0) in participants with a history of diabetes, 2.1 (95% CI, 2.0-2.2) in those with stroke, 2.0 (95% CI, 1.9-2.2) in those with MI, 3.7 (95% CI, 3.3-4.1) in those with both diabetes and MI, 3.8 (95% CI, 3.5-4.2) in those with both diabetes and stroke, 3.5 (95% CI, 3.1-4.0) in those with both stroke and MI, and 6.9 (95% CI, 5.7-8.3) in those with diabetes, stroke, and MI. The HRs from the Emerging Risk Factors Collaboration were similar to those from the more recently recruited UK Biobank. The HRs were little changed after further adjustment for markers of established intermediate pathways (eg, levels of lipids and blood pressure) and lifestyle factors (eg, smoking, diet). At the age of 60 years, a history of any 2 of these conditions was associated with 12 years of reduced life expectancy and a history of all 3 of these conditions was associated with 15 years of reduced life expectancy. CONCLUSIONS AND RELEVANCE Mortality associated with a history of diabetes, stroke, or MI was similar for each condition. Because any combination of these conditions was associated with multiplicative mortality risk, life expectancy was substantially lower in people with multimorbidity.

Cohort Profile: Scottish Health and Ethnicity Linkage Study of 4.65 million people exploring ethnic variations in disease in Scotland

: imported for journal id 300 on Dec 03, 2001, no letter sent Sent to referee - Referee Sent: 16-Nov-00 Expected: 16-Dec-00 Arrived: 12-Dec-00 MsID: IJE/2000/000462 - Major Revision - Last reminder: Sent to referee - Referee Sent: 05-Mar-01 Expected: 05-Apr-01 Arrived: 26-Apr-01 MsID: IJE/2001/000086 - Reject - Last reminder: 06-Apr-01 Thank you - Referee Sent: Expected: Arrived: MsID: IJE/2001/000086 - - Last reminder: Acknowledgement - Correspond Sent: 04-Jul-01 Expected: Arrived: MsID: IJE/2001/000382 - - Last reminder: decision - Correspond Sent: 30-Jul-01 Expected: Arrived: MsID: IJE/2001/000382 - - Last reminder: (Bhopal, Raj S)

Myocardial infarction incidence and survival by ethnic group: Scottish Health and Ethnicity Linkage retrospective cohort study

Objective Inequalities in coronary heart disease mortality by country of birth are large and poorly understood. However, these data misclassify UK-born minority ethnic groups and provide little detail on whether excess risk is due to increased incidence, poorer survival or both. Design Retrospective cohort study. Setting General resident population of Scotland. Participants All those residing in Scotland during the 2001 Census were eligible for inclusion: 2 972 120 people were included in the analysis. The number still residing in Scotland at the end of the study in 2008 is not known. Primary and secondary outcome measures As specified in the analysis plan, the primary outcome measures were first occurrence of admission or death due to myocardial infarction and time to event. There were no secondary outcome measures. Results Acute myocardial infarction (AMI) incidence risk ratios (95% CIs) relative to white Scottish populations (100) were highest among Pakistani men (164.1 (142.2 to 189.2)) and women (153.7 (120.5, 196.1)) and lowest for men and women of Chinese (39.5 (27.1 to 57.6) and 59.1 (38.6 to 90.7)), other white British (77 (74.2 to 79.8) and 72.2 (69.0 to 75.5)) and other white (83.1 (75.9 to 91.0) and 79.9 (71.5 to 89.3)) ethnic groups. Adjustment for educational qualification did not eliminate these differences. Cardiac intervention uptake was similar across most ethnic groups. Compared to white Scottish, 28-day survival did not differ by ethnicity, except in Pakistanis where it was better, particularly in women (0.44 (0.25 to 0.78)), a difference not removed by adjustment for education, travel time to hospital or cardiac intervention uptake. Conclusions Pakistanis have the highest incidence of AMI in Scotland, a country renowned for internationally high cardiovascular disease rates. In contrast, survival is similar or better in minority ethnic groups. Clinical care and policy should focus on reducing incidence among Pakistanis through more aggressive prevention.

Measures of socioeconomic position are not consistently associated with ethnic differences in cardiovascular disease in Scotland: methods from the Scottish Health and Ethnicity Linkage Study (SHELS)

BACKGROUND Ethnic health inequalities are substantial. One explanation relates to socioeconomic differences between groups. However, socioeconomic variables need to be comparable across ethnic groups as measures of socioeconomic position (SEP) and indicators of health outcomes. METHODS We linked self-reported SEP and ethnicity data on 4.65 million individuals from the 2001 Scottish Census to hospital admission and mortality data for cardiovascular disease (CVD). We examined the direction, strength and linearity of association between eight individual, household and area socioeconomic measures and CVD in 10 ethnic groups and the impact of SEP adjustment. RESULTS There was wide socioeconomic variation between groups. All eight measures showed consistent, positive associations with CVD in White populations, as did educational qualification in non-White ethnic groups. For other SEP measures, associations tended to be consistent with those of White groups though there were one or two exceptions in each non-White group. Multiple SEP adjustment had little effect on relative risk of CVD for most groups. Where it did, the effect varied in direction and magnitude (for example increasing adjusted risk by 23% in Indian men but attenuating it by 11% among Pakistani women). CONCLUSIONS Across groups, SEP measures were inconsistently associated with CVD hospitalization or death, with effect size and direction of effect after adjustment varying across ethnic groups. We recommend that researchers systematically explore the effect of their choice of SEP indicators, using standard multivariate methods where appropriate, to demonstrate their cross-ethnic group validity as potential confounding variables for the specific groups and outcomes of interest.

Ethnic variations in chest pain and angina in men and women: Scottish Ethnicity and Health Linkage Study of 4.65 million people.

Background: European research on ethnic variations in cardiovascular disease has mostly examined mortality endpoints using country of birth as a proxy for ethnicity. We report on chest pain and angina by ethnic group. Design and methods: Retrospective cohort linking the Census 2001 for Scotland (providing 14 ethnic group categories) and hospital discharge/community and hospital deaths data. Directly age-standardized rates and rate ratios were calculated. Risk ratios were adjusted for age and then highest educational qualification of the individual using Poisson regression. Ratios were multiplied by 100 and 95% confidence intervals (CI) were calculated. The reference was the White Scottish population (100). In the results below, the 95% CI excludes 100. Results: There was raised chest pain mortality/hospital discharge risk in Indian men (rate ratio 141.2), Other South Asian women (rate ratio 140.9), and Pakistanis (rate ratio 216.2 in men, 243.0 in women). Rate ratios were lowest in other White British (rate ratio 76.1 in men, 73.7 in women) and Chinese (rate ratio 67.6 in men, 76.7 in women). Adjustment for age and education attenuated, but did not abolish, differences in other White British (risk ratio from 73.5 to 83.5) and Pakistani (risk ratio from 209.0 to 198.2) male populations and increased them in most others, e.g. other South Asian men (from risk ratio of 128.9 to 140.1). Pakistani populations had the highest risk of angina (rate ratio 189.3 in men, 159.7 in women). Other White British (rate ratio 81.4 for men, 78.0 for women), Other White (rate ratio 89.6 men, 85.2 women), and Chinese (rate ratio 60.5 men, 67.4 women) had the lowest risk. Adjustment for education did not greatly alter these patterns. Conclusions: There were important ethnic variations. The results call for replication elsewhere in Europe and targeted prevention programmes and vigilant diagnosis and management by clinicians.

Ethnic variations in the incidence and mortality of stroke in the Scottish Health and Ethnicity Linkage Study of 4.65 million people

Background: Ethnic variations in stroke require more European studies, especially as differences are reportedly large. Methods: We created a retrospective cohort study of 4.65 million people in Scotland linking ethnicity from the census and stroke incidence and mortality from NHS databases. Rate ratios using direct age standardization and risk ratios were calculated, the latter to model the influence of educational qualification in a Poisson regression model. Results: Age-adjusted rate ratios varied little, compared to the White Scottish group (reference value 100) and the 95% CIs usually included 100, e.g. higher in Pakistani men (120.5, 95% CI 95.2–145.8) and in African men (137.9, 95% CI 91.5–184.4) but not in Pakistani or African women. Stroke rates were low in the Other White British (78.3, 95% CI 75.4−81.2 in men and 84.9, 95% CI 82.0−87.8 in women), Other White (89.8, 95% CI 81.5−98.1 in men and 88.8, 95% CI 80.9−96.7 in women) and Chinese men (70.3, 95% CI 45.7−94.8). Adjusting for highest educational qualification attenuated some and augmented other risk ratios, e.g. in Other White British men, the risk ratio changed from 71.4 to 80.2 (95% CI 74.2−86.6) and in African men from 124.2 to 138.8 (95% CI 107.7−178.8). Conclusions: Ethnic variations deserve further study, including in White European origin subgroups and the Chinese. Extremely high rates in South Asian and African origin were not corroborated in Scotland. Linkage methods are practical in Europe.

Does the ‘Scottish effect’ apply to all ethnic groups? All-cancer, lung, colorectal, breast and prostate cancer in the Scottish Health and Ethnicity Linkage Cohort Study

Background and objectives Although ethnic group variations in cancer exist, no multiethnic, population-based, longitudinal studies are available in Europe. Our objectives were to examine ethnic variation in all-cancer, and lung, colorectal, breast and prostate cancers. Design, setting, population, measures and analysis This retrospective cohort study of 4.65 million people linked the 2001 Scottish Census (providing ethnic group) to cancer databases. With the White Scottish population as reference (value 100), directly age standardised rates and ratios (DASR and DASRR), and risk ratios, by sex and ethnic group with 95% CI were calculated for first cancers. In the results below, 95% CI around the DASRR excludes 100. Eight indicators of socio-economic position were assessed as potential confounders across all groups. Results For all cancers the White Scottish population (100) had the highest DASRRs, Indians the lowest (men 45.9 and women 41.2) and White British (men 87.6 and women 87.3) and other groups were intermediate (eg, Chinese men 57.6). For lung cancer the DASRRs for Pakistani men (45.0), and women (53.5), were low and for any mixed background men high (174.5). For colorectal cancer the DASRRs were lowest in Pakistanis (men 32.9 and women 68.9), White British (men 82.4 and women 83.7), other White (men 77.2 and women 74.9) and Chinese men (42.6). Breast cancer in women was low in Pakistanis (62.2), Chinese (63.0) and White Irish (84.0). Prostate cancer was lowest in Pakistanis (38.7), Indian (62.6) and White Irish (85.4). No socio-economic indicator was a valid confounding variable across ethnic groups. Conclusions The ‘Scottish effect’ does not apply across ethnic groups for cancer. The findings have implications for clinical care, prevention and screening, for example, responding appropriately to the known low uptake among South Asian populations of bowel screening might benefit from modelling of cost-effectiveness of screening, given comparatively low cancer rates.

Major ethnic group differences in breast cancer screening uptake in Scotland are not extinguished by adjustment for indices of geographical residence, area deprivation, long-term illness and education

Background:Breast cancer screening data generally show lower uptake in minority ethnic groups. We investigated whether such variations occur in Scotland.Methods:Using non-disclosive computerised linkage we combined Scottish breast screening and Census 2001 data. Non-attendance at first breast-screening invitation (2002–2008) was compared between 11 ethnic groups using age-adjusted risk ratios (RR) with 95% confidence intervals (CI), multiplied by 100, using Poisson regression.Results:Compared with the White Scottish (RR=100), non-attendance was similar for Other White British (99.5, 95% CI 96.1–103.2) and Chinese (112.8, 95% CI 96.3–132.2) and higher for Pakistani (181.7, 95% CI 164.9–200.2), African (162.2, 95% CI 130.8–201.1), Other South Asian (151.7, 95% CI 118.9–193.7) and Indian (141.7, 95% CI 121.1–165.7) groups. Adjustment for rural vs urban residence, long-term illness, area deprivation and education, associated with risk of non-attendance, increased the RR for non-attendance except for Pakistani women where it was modestly attenuated (RR=164.9, 149.4–182.1).Conclusion:Our data show important inequality in breast cancer screening uptake, not attenuated by potential confounding factors. Ethnic inequalities in breast screening attendance are of concern especially given evidence that the traditionally lower breast cancer rates in South Asian groups are converging towards the risks in the White UK population. Notwithstanding the forthcoming review of breast cancer screening, these data call for urgent action.

Disparate patterns of hospitalisation reflect unmet needs and persistent ethnic inequalities in mental health care: the Scottish health and ethnicity linkage study

Objectives The presence and extent of mental health inequalities in Scotland is unclear. We investigated ethnic variations in psychiatric hospitalisations and compulsory treatment in relation to socioeconomic indicators. Design In a retrospective cohort study design, using data linkage methods, we examined ethnic variations in psychiatric [any psychiatric, mood (affective), and psychotic disorders) hospitalisations and use of the Mental Health (Care and Treatment) (Scotland) Act 2003 (Emergency Detentions (ED), Short-Term Detentions (STD) and Compulsory Treatment Orders (CTO)] using age (and sex for compulsory treatment), car ownership, and housing tenure adjusted risk ratios (RR). 95% CIs for the data below exclude the reference White Scottish group value (100). Results Compared to the White Scottish population, Other White British men and women had lower hospitalisation from any psychiatric disorder (RR = 77.8, 95% CI: 71.0–85.2 and 85.8, 95% CI: 79.3–92.9), mood disorder (91.2, 95% CI: 86.9–95.8 and 83.6, 95% CI: 75.1–93.1), psychotic disorder (67.1, 95% CI: 59.9–75.2 and 78.5, 95% CI: 67.6–91.1), CTO (84.6, 95% CI: 72.4–98.9) and STD (88.2, 95% CI: 78.6–99.0). Any Mixed Background women had higher hospitalisation from any psychiatric disorder (137.2, 95% CI: 110.9–169.6) and men and women had a higher risk of psychotic disorder (200.6, 95% CI: 105.7–380.7 and 175.5, 95% CI: 102.3–301.2), CTO (263.0, 95% CI: 105.4–656.3), ED (245.6, 95% CI: 141.6–426.1) and STD (311.7, 95% CI: 190.2–510.7). Indian women had lower risk of any psychiatric disorder (43.2, 95% CI: 28.0–66.7). Pakistani men had lower risk of any psychiatric disorder (78.7, 95% CI: 69.3–89.3), and higher risk of mood disorders (117.5, 95% CI: 100.2–137.9). Pakistani women had similar risk of any psychiatric and mood disorder however, a twofold excess risk of psychotic disorder (227.3, 95% CI: 195.8–263.8). Risk of STD was higher in South Asians (136.9, 95% CI: 109.0–171.9). Chinese men and women had the lowest risk of hospitalisation for any psychiatric disorder (35.3, 95% CI: 23.2–53.7 and 44.5, 95% CI: 30.3–65.5) and mood disorder (51.5, 95% CI: 31.0–85.4 and 47.5, 95% CI: 23.2–97.4) but not psychotic disorders and higher risk for CTO (181.4, 95% CI: 121.0–271.0). African women had higher risk of any psychiatric disorder (139.4, 95% CI: 119.0–163.2). African men and women had the highest risk for psychotic disorders (230.8, 95% CI: 177.8–299.5 and 240.7, 95% CI: 163.8–353.9) and were also overrepresented in STD (214.3, 95% CI: 122.4–375.0) and CTO (486.6, 95% CI: 231.9–1021.1). Differences in hospitalisations were not fully attenuated when adjusted for car ownership and housing tenure and the effect of these adjustments varied by ethnic group. Conclusion Our data show disparate patterns of psychiatric hospitalisations by ethnic group in Scotland providing new observations concerning the mental health care experience of Chinese, Mixed background and White subgroups not fully explained by socioeconomic indicators. For South Asian and Chinese groups in particular, our data indicate under and late utilisation of mental health services. These data call for monitoring and review of services.