Patterns of drinking behaviour and incidence of diseases amongst Scottish adults

1. Patterns of drinking behaviour and incidence of diseases amongst Scottish adults Presented by: Dami Olajide (d.olajide@abdn.ac.uk)

2. Background • Alcohol is linked to major diseases and a major risk factor for morbidity and mortality in the UK: • In Scotland, 2,882 (or 5% of total) deaths are attributable to alcohol & 1,492 deaths prevented in 2003 (Grant et al 2010). • Alcohol attributable deaths increased by 15% from 2001-2005, while hospital admissions increased by 7% (ScotPHO2008). • Important heterogeneities exists in alcohol consumption; • Protective effects of alcohol; • The majority of diseases/conditions are partly attributable to alcohol; • Associated burden of diseases vary by demographics (e.g. age and gender) & other characteristics; • Individuals tend to under-report their drinking behaviour by up to 50% (ScotPHO 2008).

3. Aim and objectives • Aim is to shed some light on the nature of heterogeneities in alcohol consumption and disease burden amongst Scottish adults: • Exploit data linkage to identify the underlying patterns of consumption, based on individuals’ self-reported drinking status and hospital admissions; and • Examine associated characteristics of the individual. • Major contribution is that (i) and (ii) are jointly undertaken in a single model.

4. Methods (1): Data • Linked data set: • Hospitalisation episodes from the Scottish Morbidity Records (SMR); • Respondent characteristics from the Scottish Health Survey (SHeS). • Incidence of an alcohol-related disease/condition: • Presence of specific ICD9 & ICD10 codes (N=4,984 or 24%) • Wholly or partially attributable to alcohol consumption (98% partially) • Disease categories: • abdominal/liver, cancers, heart (16%), nervous system/mental disorder, others-conditions; none.

5. Data (ctd.) • Alcohol consumption (units per week): • 12 polytomous responses reclassified into 6: • Never drinker; Ex-drinker; Occasional or < 7 (42%); Over 7 – 14; Over 14-28; Over 28. • Respondent characteristics: • Age categories (16+), marital status, education, occupational social class, deprivation, health board (Greater Glasgow). • Average age = 46 years; female majority (55%), No education qualification (36%).

6. Methods (2): Approach • Latent class analysis (LCA) approach • statistical method used to identify homogenous, mutually exclusive groups (classes) existing within a heterogeneous population. • Widely used in health care research to analyse behavioural patterns. • Latent class regression model • A single model for LCA for polytomous responses + regression (Linzer and Lewis 2011) • Item-response probabilities are obtained from LCA based on self-reported drinking status and related diseases/conditions • Characteristics associated with class membership are then obtained from regression. • Separate analysis for females and males.

7. Results (1): Latent class profiles

8. Profiles continued (notes only)

9. Results (2): Graphical displays Fig.2. Males Fig.1. Females

10. Characteristics of class membership

11. Preliminaryconclusions • Given their patterns of alcohol and related diseases/conditions: • Important gender differences at moderate level of risk (2/1) (age, education qualification, social class, health board). • Women with better education and social class are at a lower risk of alcohol-related diseases/conditions than men of similar characteristic. • No clear gender differences in characteristics at highest level of risk (3/1). • Some indication of under-reporting: objective measures of alcohol consumption may reduce under-reporting. • Diseases are largely partially related to alcohol. • Further work: policy implications of findings