[A psychiatric morbidity study of the population attending the Basauri Health Center]. / Estudio de morbilidad psiquiátrica en la población atendida en el centro de salud de Basauri.

OBJECTIVE: To calculate the probable prevalence of mental illness in our clinics and to evaluate how it is detected by Primary Care (PC) doctors. DESIGN: Crossover study in two parts. SITE. Basauri Health Centre (Vizcaya). PARTICIPANTS: A sample made up of patients who attended the clinic without prior appointment during ten days in February and Marc, 1990. MAIN MEASUREMENTS AND RESULTS: In the first part, 10 PC doctors distributed the GHQ-28 questionnaire to 500 patients. In the second part, qualified staff administered the standardised psychiatric interview (SPI) to a sub-sample. 41.55% were possible psychiatric cases (GHQ-28 > 6). 17.94% were diagnosed by the doctors (SD) as psychiatric cases. Prevalences adjusted to the SPI were 19% and 21% for the GHQ-28 and SD respectively. CONCLUSIONS: The GHQ-28 obtained high sensitivity (0.82%) and low specificity (60%), which characterises it as a good screening test, but a bad diagnostic method. The doctors obtained low sensitivity (0.29) and high specificity (89.7%); thus underdiagnosing mental illness, but being more accurate in their diagnoses.