Recurrent risk of hospitalization among older people with problematic alcohol use: a multiple failure-time analysis with a discontinuous risk model

Background and aims Older people with problematic alcohol use vary in psychosocial functioning, age of onset for problem drinking and use of other drugs. The study measured the differential risks of all-cause, alcohol-, polydrug- and psychiatric-related repeated hospitalizations among older people with problematic alcohol use. Design A linked register-based cohort study with discontinuous multiple-failure (time-to-repeated-event) data. Hospitalization and mortality were considered as failure. Setting Sweden, March 2003-November 2017, using data from the Addiction Severity Index (ASI) register linked to National Inpatient Register and the Swedish cause of death register. Participants Participants aged 50 years and older (n = 1741; 28.2% women), with one or more alcohol problem days in the 30 days before an ASI assessment. Measurements Five mutually exclusive latent classes of problematic alcohol use, identified with 11 ASI items, were the independent variables: 'late onset with fewer consequences (LO:FC; reference group)'; 'early onset/prevalent multi-dimensional problems (EO:MD)'; 'late onset with co-occurring anxiety and depression (LO:AD)'; 'early onset with co-occurring psychiatric problems (EO:PP)'; and 'early onset with major alcohol problem (EO:AP)'. Covariates included socio-demographic characteristics, previous hospitalization and Elixhauser comorbidity index. Outcome measurements included recurrent hospitalization and/or mortality due to: (a) all-cause, (b) alcohol-related disorders and diseases (c) polydrug use and (d) other psychiatric disorders. Findings During the study period, more than 75% were hospitalized at least once or died. 57.3% were hospitalized with alcohol-related, 8.5% with polydrug use and 18.5% with psychiatric-related diagnoses. Compared with LO:FC, EO:PP had higher risk for all-cause [adjusted hazard ratio (aHR) = 1.27, 95% confidence interval (CI) = 1.02-1.59] and alcohol-related (aHR = 1.34, 95% CI = 1.02-1.75) hospitalizations. Adjusted risks for polydrug-related hospitalization were 2.55, 95% CI = 1.04-6.27 for EO:MD and 2.62, 95% CI = 1.07-6.40 for EO:PP. Adjusted risk for psychiatric-related hospitalization was higher for LO:AD (aHR = 1.78, 95% CI = 1.16-2.73 and EO:PP (aHR = 2.03, 95% CI = 1.22-3.38). Conclusions Older addiction service users in Sweden have varying risks of hospitalization due to alcohol use, polydrug use and psychiatric disorders. Older people with problematic alcohol use who have multiple needs and are assessed in social services may benefit from earlier interventions with an integrated focus on substance use and mental health.