The incidence of first-episode schizophrenia-spectrum psychosis in adolescents and young adults in montreal: an estimate from an administrative claims database.
OBJECTIVE
There has been increasing interest in the psychiatric literature on research and service delivery focused on first-episode psychosis (FEP), and accurate information on the incidence of FEP is crucial for the development of services targeting patients in the early stages of illness. We sought to obtain a population-based estimate of the incidence of first-episode schizophrenia-spectrum psychosis (SSP) among adolescents and young adults in Montreal.


METHODS
Population-based administrative data from physician billings, hospitalizations, pharmacies, and public health clinics were used to estimate the incidence of first-episode SSP in Montreal. A 3-year period (2004-2006) was used to identify patients with SSP aged 14 to 25 years. We used a 4- to 6-year clearance period to remove patients with a history of any psychotic disorder or prescription for an antipsychotic.


RESULTS
We identified 456 patients with SSP, yielding a standardized annual incidence of 82.9 per 100 000 for males (95% CI 73.7 to 92.1), and 32.2 per 100 000 for females (95% CI 26.7 to 37.8). Using ecologic indicators of material and social deprivation, we found a higher-incidence proportion of SSP among people living in the most deprived areas, relative to people living in the least deprived areas.


CONCLUSIONS
Clinical samples obtained from psychiatric services are unlikely to capture all treatment-seeking patients, and epidemiologic surveys have resource-intensive constraints, making this approach challenging for rare forms of psychopathology; therefore, population-based administrative data may be a useful tool for studying the frequency of psychotic disorders.
Department of Epidemiology, McGill University, Montreal, Quebec.
Kelly K
KK
Anderson
Rebecca
R
Fuhrer
Michal
M
Abrahamowicz
Ashok K
AK
Malla
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003625:Data Collection / Q000379:methods; D003695:Delivery of Health Care / Q000706:statistics & numerical data; D017050:Episode of Care; D005260:Female; D006801:Humans; D015994:Incidence; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D008605:Mental Health Services / Q000706:statistics & numerical data; D011159:Population Surveillance; D011569:Psychiatric Status Rating Scales; D011610:Psychosocial Deprivation; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D011792:Quebec / Q000453:epidemiology; D012559:Schizophrenia / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents