Are we overestimating the beneficial effects of moderate alcohol consumption in later life? The sick quitter and sick non-starter hypotheses Linda Ng Fat PhD Student UCL Population Health Supervisors: Dr Nicola Shelton, Dr Noriko Cable, James Kneale, Professor Sir Michael Marmot

The J/U-Curve among middle age cohorts in observational studies 2 Corrao, G, et al, Addiction, (10): p Alcohol consumption against risk of coronary heart disease

J-Curve for Total mortality; ex-drinkers separated Klatsky, A. L. and N. Udaltsova (2007). Annals of Epidemiology 17(5): S63-S67 3

Is the relationship causal? Meets Bradford Hill Criteria of Consistency of findings and biological plausibility - Alcohol may increase high-density lipoprotein (HDL) cholesterol Some evidence to suggest this is the case from RCT & change in biomarkers. But limited due to –Small sample size & duration –No RCT for incidence of CVD Thus majority of studies have relied on observational data 4

Examples of reporting in the media Source: BBC News 5

A health message that is confusing? 26% of people drink alcohol because they believe it to have health benefits (Mintel 2004). In US a third cited possible health benefits as a motivation, whilst only 10% identified breast cancer as a risk (Mukamal et al 2008) Implications of the J-shape 6

Further criticisms outside the sick-quitter bias 1.Moderate drinkers have a better social position and adopt healthier lifestyles than non-drinkers. 2.Validity of the ‘lifetime abstainer group’ 3.Poor health may be a reason why some people never ever start drinking 7

Odds of being a non-drinker vs. drinker aged 18 to 34 years Health survey for England 2006 & 08 Odds Ratio (and 95% C.I) 8 Adjusted for age, ethnicity, region, income, education, marital status, parental status, LLSI, anxiety, physical activity and smoking N G F AT, L., & S HELTON, N. Addiction, (9): p

Odds of being a non-drinker vs. drinker aged 18 to 34 years Health survey for England 2006 & 08 Highest Qualification Income Odds Ratio (and 95% C.I) 9 Adjusted for age, ethnicity, region, income, education, marital status, parental status, LLSI, anxiety, physical activity and smoking N G F AT, L., & S HELTON, N. Addiction, (9): p

The Sick Non-starter hypothesis Non-drinkers have higher rates of self-reported poor health in young adulthood (Power, C 1998) even after adjusting for a range of social and demographic factors (Ng Fat, L & Shelton, N 2012) Poor health a reason why some never ever take up drinking? Hypotheses A. Poor health precedes non-drinking early in the life course B. Continuous poor health is associated with continuous non- drinking 10

Data sets Medical data 16 years Non-drinker 23 years Non-drinker 33 years Non-drinker 42 years Medical data 11 years Non-drinker 26 years Non-drinker 30 years Non-drinker 34 years The National Child Development Study 1958 (NCDS) The British Cohort Study 1970 (BCS) A A B B 11

Data sets Medical data 16 years Non-drinker 23 years Non-drinker 33 years Non-drinker 42 years Medical data 11 years Non-drinker 26 years Non-drinker 30 years Non-drinker 34 years The National Child Development Study 1958 (NCDS) The British Cohort Study 1970 (BCS) A A B B 12

NCDS 1958 Medical conditions at 16 years (p<0.05) Drinking frequency at 23 years 13

BCS 1970 Self-report conditions suffered since 16 years reported at 26 years (p<0.05) Drinking frequency at 26 years 14

Logistic Regression Outcome: 1.Lifetime abstainer: Non-drinker in each sweep (NCDS 1958 and BCS 1970) 2.Self-identified lifetime abstainers: Current status measure from those who reported “never having had an alcoholic drink” (BCS 1970) Exposure: Change in limiting longstanding illness since 23 (NCDS 1958) Change in longstanding illness since 26 (BCS 1970) Controls: Sex, malaise inventory score (mental health), highest qualification, marital status, parental status 15

Odds ratios Adjusted for sex, highest qualification, marital status, parental status and malaise score Lifetime abstainers 33 years No LLSILLSI 23 years No LLSI LLSI Life time abstainers Self-identified LA 30 years No LLILLI NO LLILLI 26 years No LLI LLI ***2.07*2.11* NCDS 1958 BCS **4.50** N G F AT, L., et al (2013) Journal of Epidemiology and Community Health, doi: /jech

Odds ratios Adjusted for sex, highest qualification, marital status, parental status and malaise score Lifetime abstainers 42 years No LLSILLSI 23 & 33 years No LLSI12.13** LLSI3.16***7.02*** Life time abstainersSelf-Identified LA 34 years No LLILLI NO LLILLI 26 &30 years No LLI LLI ***2.02**2.80*** NCDS 1958 BCS N G F AT, L., et al (2013) Journal of Epidemiology and Community Health, doi: /jech

Conclusions and Implications Poor health from an early age and persistent poor health is associated with persistent non-drinking (lifetime abstention) from early adulthood Non-drinkers in later life may suffer from double bias from sick-quitters and sick non-starters, therefore may be an inadequate reference group against drinkers 18

Strengths Limitations Small sample size of lifetime abstainers Missing lost to attrition (MNAR) Participants may drink in between waves Consistent findings from two large representative cohorts and between two measures of non-drinkers (lifetime abstainer and self-identified LA) Consistent findings between two measures of health (LLI and LLSI) 19

Acknowledgements: Dr Nicola Shelton, Dr Noriko Cable, Dr James Kneale, Professor Sir Michael N G F AT, L., C ABLE, N., M ARMOT, M. & S HELTON, N. (2013) Persistent long-standing illness and non-drinking over time, implications for the use of lifetime abstainers as a control group, Journal of Epidemiology and Community Health, doi: /jech N G F AT, L., & S HELTON, N Associations between self-reported illness and non-drinking in young adults. Addiction, (9): p Impact