Hospitalization in a cohort seeking treatment for illicit drug use in Finland.

Illicit drug use is associated with various health problems that result in inpatient hospital admissions. The primary objective of this study was to examine all-cause and cause-specific hospitalizations by gender. The cohort comprised 4817 drug users (3365 males and 1452 females) who sought treatment in Helsinki between 1997 and 2008. Data on hospitalizations that occurred among these clients were extracted from the National Hospital Discharge Register. Crude hospitalization rates (CHRs) and standardized hospitalization ratios (SHRs) with 95% confidence intervals (CIs) were calculated, and Kaplan-Meier analysis with Log-Rank test was used to compare survival in terms of time to hospitalization between males and females. At the end of the follow-up period, 84.5% of females and 73.3% of male clients were hospitalized at least once. Female clients had higher CHR (607.6/1000 person-years, 95%CI: 594.1-621.4) than males (511.0/1000, 95% CI: 502.9-519.3), and had significantly poorer survival than males (Log-Rank test, P<0.001). However, male clients stayed longer on admission than females (mean length of stay 70.2days versus 60.7days respectively, P<0.001). Compared to the national rates, excess hospitalizations were noted in both males (SHR=6.3, 95% CI: 6.2-6.4) and female clients (SHR=4.3, 95% CI: 4.2-4.4). Based upon primary discharge diagnosis, the leading causes of hospitalizations included psychosis (n=622), schizophrenia (n=604), depression (n=497), cardiovascular diseases (n=223), hepatitis C (n=116), HIV (n=81), and other types of hepatitis (n=45). Female clients were more likely than males to be admitted for hepatitis C infection (P<0.001) and depression (P<0.001). Male clients were more likely than females to be diagnosed with other types of hepatitis infections (P=0.032) and psychosis (P=0.035). Excess hospitalizations signify excessive utilization of health resources. Effective drug abuse treatment, gender-sensitive approaches, and regular health checks can help to reduce morbidity. Appropriate measures are needed to address psychiatric problems in this population.