Modeling the geographic distribution of serious mental illness in New Zealand.
OBJECTIVE
This study aims to estimate, apply, and validate a model of the risk of serious mental illness (SMI) in local service areas throughout New Zealand.


METHODS
The study employs a secondary analysis of data from the Te Rau Hinengaro Mental Health Survey of 12,992 adults aged 16 years and over from the household population. It uses small area estimation (SAE) methods involving: (1) estimation of a logistic model of risk of SMI; (2) use of the foregoing model for computing estimates, using census data, for District Board areas; (3) validation of estimates against an alternative indicator of SMI prevalence.


RESULTS
The model uses age, ethnicity, marital status, employment, and income to predict 92.2 % of respondents' SMI statuses, with a specificity of 95.9 %, sensitivity of 16.9 %, and an AUC of 0.73. The resulting estimates for the District Board areas ranged between 4.1 and 5.7 %, with confidence intervals from ±0.3 to ±1.1 %. The estimates demonstrated a correlation of 0.51 (p = 0.028) with rates of psychiatric hospitalization.


CONCLUSIONS
The use of SAE methods demonstrated the capacity for deriving local prevalence rates of SMI, which can be validated against an available indicator.
School of Social Work, Salem State University, 352 Lafayette Street, Salem, MA 01970, USA. chudson@salemstate.edu
Christopher G
CG
Hudson
Max W
MW
Abbott
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002391:Catchment Area, Health; D003156:Community Mental Health Services / Q000458:organization & administration*; D005260:Female; D006306:Health Surveys; D006801:Humans; D007406:Interview, Psychological; D016015:Logistic Models; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology* / Q000208:ethnology / Q000523:psychology; D008875:Middle Aged; D015233:Models, Statistical; D020380:Needs Assessment; D009520:New Zealand / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017062:Small-Area Analysis; D012959:Socioeconomic Factors; D055815:Young Adult