Social Deprivation and Psychiatric Admission Rates Among Different Diagnostic Groups

BACKGROUND: In the search for population-based indicators of need for mental health services, psychiatric admission rates have been correlated with sociodemographic variables. We explored such correlations for different diagnostic groups. METHOD: Admissions data for the 19 districts in the North West Region were derived from the Korner Episode System for 1992/93 and divided into eight broad diagnostic groups using ICD-9 codes. Admission rates per 1000 were correlated with measures of deprivation derived from the 1991 census data and with standardised mortality ratios. For the two largest diagnostic groups, correlations with age-standardised admission rates were also calculated. RESULTS: For schizophrenia/delusional disorder, eight of the 10 sociodemographic measures were significantly correlated with admission rates (Pearson's r 0.52 - 0.79). On all measures these correlations were greater than those seen for total mental illness. Significant positive correlations of a lower order were seen for organic brain syndromes and mania. Admission rates for depression, personality disorder and substance misuse were not significantly correlated with any of the sociodemographic measures. Admission rates for neurotic illness were negatively correlated with all deprivation measures, with the negative correlation statistically significant at the 5% level for ethnic composition and overcrowding. Standardising admission rates for age and repeating the analysis after removal of influential data points did not greatly alter these findings. CONCLUSIONS: The association between psychiatric admission rates and measures of deprivation varies considerably with diagnosis. Measures of social deprivation may indicate need for services for patients with psychotic disorders; admission rates for non-psychotic illnesses may reflect the availability of beds rather than need.