Objective: Examining the relationship between psychological status and survival in amyotrophic lateral sclerosis. Our hypothesis is that psychological distress is associated with greater mortality and shorter survival time than psychological well-being.
Design: Cross-sectional, longitudinal. The baseline evaluations used were disease severity and 10 psychometric tests. A psychological status score was derived from these tests. Survival status was monitored for 3.5 years. Interviewers were blinded to other interviews and data analysis.
Setting: Patient's residence.
Patients: The criteria for eligibility were diagnosis of amyotrophic lateral sclerosis by a neurologist, dementia or alcoholism absent, communication in English, and any severity or length of disease. It was a volunteer sample consisting of 144 patients from amyotrophic lateral sclerosis clinics or community-based amyotrophic lateral sclerosis support groups. In this sample 66% were men, 94% were white, mean age at diagnosis was 55 years, 79% were married, 60% had some college education, and 61% died during the study.
End points: mortality during study, survival time from intake to last follow-up.
Results: Comparison between high and low psychological score groups: 32% of high and 82% of low died; survival curves were significantly different. Controlling for confounding factors (length of illness, disease severity, age), patients with psychological distress had a greater risk of mortality (relative risk, 6.76; 95% confidence limits, 1.69 to 27.12) and greater likelihood of dying in any given time period (relative risk, 2.24; 95% confidence limits, 1.08 to 4.64) than those with psychological well-being.
Conclusion: Adjusting for confounding factors, psychological status is strongly related to outcome in amyotrophic lateral sclerosis. Further studies on psychological status should be done to confirm its prognostic value.