The meaning of illness questionnaire: reliability and validity

The reliability and validity of a recently developed Meaning of Illness Questionnaire (MIQ) is described. Questionnaire content was based on the work of Lazarus and Folkman (1984b). Three hundred twenty chronically ill subjects completed the 33-item MIQ and two open-ended questions. Subjects also completed the 45-item Psychosocial Adjustment to Illness--Self-Report Scale (PAIS-SR) described by Derogatis and Lopez (1983). Test-retest reliability for 70 subjects was, on the whole, substantial (kappa = .45 to 1.00) as was the ability of nurse clinicians to reliably categorize the qualitative component of the questionnaire into one of 12 categories (kappa = .64). The factor structure of the questionnaire supported the theoretical assumptions underlying the instrument. Three of the factors of meaning given the illness, R2 = .46, and/or three items, R2 = .60, had more power than coping behavior in explaining a person's adjustment to chronic illness. The questionnaire has accumulated reliability and validity in measuring a variety of concurrent yet divergent meanings that may be given an illness for three chronically ill populations--those with mixed cancer, rheumatological, and gastroenterological disorders.