Association between self-reported general and mental health and adverse outcomes: a retrospective cohort study of 19,625 Scottish adults.
OBJECTIVE
Self-reported general health and mental health are independent predictors of all-cause mortality. This study examines whether they are also independent predictors of incident cancer, coronary heart disease and psychiatric hospitalisation.


METHODS
We conducted a retrospective, population cohort study by linking the 19 625 Scottish adults who participated in the Scottish Health Surveys 1995-2003, to hospital admissions, cancer registration and death certificate records. We conducted Cox proportional hazard models adjusting for potential confounders including age, sex, socioeconomic status, alcohol, smoking status, body mass index, hypertension and diabetes.


RESULTS
Poor general health was reported by 1215 (6.2%) participants and was associated with cancer registrations (adjusted Hazard Ratio [HR] 1.30, 95% CI 1.10, 1.55), coronary heart disease events (adjusted HR 2.30, 95% CI 1.86, 2.84) and psychiatric hospitalisations (adjusted HR 2.42, 95% CI 1.65, 3.56). There was evidence of dose relationships and the associations remained significant after adjustment for mental health. 3172 (16%) participants had poor mental health (GHQ ≥ 4). After adjustment for general health, the associations between poor mental health and coronary heart disease events (adjusted HR 1.36, 95% CI 1.13, 1.63) and all-cause death (adjusted HR 1.38, 95% CI 1.23, 1.55) became non-significant, but mental health remained associated with psychiatric hospitalisations (fully adjusted HR 2.02, 95% CI 1.48, 2.75).


CONCLUSIONS
Self-reported general health is a significant predictor of a range of clinical outcomes independent of mental health. The association between mental health and non-psychiatric outcomes is mediated by general health but it is an independent predictor of psychiatric outcome. Individuals with poor general health or mental health warrant close attention.
Institute of Health & Wellbeing, Public Health, University of Glasgow, Glasgow, United Kingdom; Institute of Public Health & Social Sciences, Khyber Medical University, KPK, Peshawar, Pakistan.
Zia
Z
Ul-Haq
Institute of Health & Wellbeing, Public Health, University of Glasgow, Glasgow, United Kingdom.
Daniel F
DF
Mackay
Institute of Health & Wellbeing, Public Health, University of Glasgow, Glasgow, United Kingdom.
Jill P
JP
Pell
D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking; D015992:Body Mass Index; D015331:Cohort Studies; D003327:Coronary Disease / Q000453:epidemiology*; D006304:Health Status; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology*; D008603:Mental Health / Q000706:statistics & numerical data*; D009369:Neoplasms / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012606:Scotland / Q000453:epidemiology; D057566:Self Report; D012737:Sex Factors; D012907:Smoking; D012959:Socioeconomic Factors