Predictors of burden and infectious illness in schizophrenia caregivers

The objective of the study was to test predictive models of schizophrenia caregiver burden and infectious illness episodes for caregivers who had regular contact with their mentally ill family members.

A nurse interviewer, blind to the patient's symptoms, caregiver burden, and psychosocial status, administered the Health Review to 70 caregivers. A second family interviewer, blind to caregiver health status and patient symptoms, assessed caregiver resources (eg, active coping and social support), vulnerabilities (eg, anger expression and passive coping) and burden. Concurrently, independent patient raters, blind to caregiver health and psychosocial status, assessed caregiver stressors. The Brief Psychiatric Rating Scale and the Modified Scale for the Assessment of Negative Symptoms were used to assess the severity of positive (eg, hallucinations and delusions) and negative (eg, anhedonia and asociality) symptoms, respectively.

Predictive models, including measures of stressors, resources, and vulnerability factors for caregiver burden and for presence of infectious illness, were each highly significant, accounting for 40% and 29% of the variance, respectively. However, the specific measures that predicted burden and infectious illness differed. Greater burden was predicted by more severe patient negative symptoms (stressor), greater anger control and blame self-coping (vulnerability), and decreased tangible social support (resource). Presence of infectious illness episodes was predicted by more severe patient positive symptoms (stressor) and less satisfaction with social support while controlling for the frequency of reporting on the Health Review. When scores from the Brief Psychiatric Rating Scale (stressors) were categorized into quartiles, it was found that the frequency of infectious illness in the highest quartile was four times that in the lowest quartile. Other results indicated that even though burden was not associated with infectious illness, it was associated with "continuing health problems," perceived stress, and depression.

These data indicate that although schizophrenia caregiver burden and infectious illness are predicted by measures of patient stressors, vulnerabilities, and resources, the specific measures predicting these outcomes differ. The results also call attention to the powerful influence of patient symptoms as a predictor of burden and the presence of infectious illness among caregivers.