Improving Reliability of the Assessment of the Life Course of Schizophrenia

Abstract

Objective: Life course studies of schizophrenia that have used a 3-phase model (onset, course, and outcome) have had their use restricted owing to differences in definition and methodology. The purpose of this investigation was to describe life course data in mathematical terms and to compare the results with the findings from other life course studies. Method:The study population was comprised of 128 of 137 people who were first admitted for schizophrenia to 1 of the 2 mental hospitals in Alberta in 1963 and followed until 1997 or death. Patient evaluations were based on retrospective and contemporaneous information collected from the patients and hospital files, treatment records, and family members. Mathematically derived ratings were formulated for course, outcome, and onset (pre-admission years). The distribution of the resulting 8 life course types was compared with profiles drawn from other such studies reported in the literature. Results:The use of mathematical descriptions of onset, course, and outcome produced profiles that did not closely match the results of other investigations, largely owing to inconsistency across studies. Further, the present approach to outcome measurement produced results that were less favourable than those found in other studies. Conclusions:Studies on the life course of schizophrenia could be made more comparable by specifying mathematically expressed operational definitions of onset, course, and outcome. Nonetheless, the use of the term outcome can be questioned as it implies an assessment at a specific time rather than providing a summary statement of the quality of a life.Can J Psychiatry. 2010;55(11):729-735. Clinical Implications· Schizophrenia life course judgments are improved by mathematical specification of the parameters of onset, course, and outcome. · Current results suggest a pessimistic prognosis for people hospitalized for schizophrenia. · Investigations of onset, course, and outcome differ on many important parameters, making valid comparisons extremely difficult to realize. Limitations· Overall life course ratings were made by only 1 person, therefore we had no direct measure of the reliability of these ratings. · The assessment of schizophrenia has changed somewhat since the index cases were selected in 1963. · Although subjects were selected early, and records were consulted where possible, much of the life course information was collected retrospectively.

Long-term course and outcome in schizophrenia: a 34-year follow-up study in Alberta, Canada

“…Long-term studies are of particular importance in advancing our understanding of the course and outcome of schizophrenia, but there are design issues that must be considered (McGlashan et al 1988; Thompson et al 2010). The period when the study is commenced is likely to affect the diagnostic criteria used and the treatments to which subjects are exposed.…”