Suicide among patients with amyotrophic lateral sclerosis
 

Suicide among patients with amyotrophic lateral sclerosis
Fang Fang1, Unnur Valdimarsdóttir1,2, Carl Johan Fürst3, Christina Hultman1,4, Katja Fall1, Pär Sparén1 and Weimin Ye1
1Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, 2Centre of Public Health Sciences, University of Iceland, Reykjavík, Iceland, 3Stockholms Sjukhem Palliative Care Unit, Stockholm and 4Department of Neuroscience, Psychiatry, Ulleraker, Uppsala University, Uppsala, Sweden


Correspondence to: Fang Fang, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, PO Box 281, 171 77 Stockholm, Sweden E-mail: fang.fang@ki.se

Studies on the suicide risk among patients with amyotrophic lateral sclerosis (ALS) in countries without legalized euthanasia or assisted suicide are important additions to data on the wish to die of these patients. We conducted a population-based cohort study in Sweden between 1965 and 2004, which comprised of 6642 patients with incident ALS identified from the Swedish Inpatient Register. We calculated the standardized mortality ratios (SMRs) of suicide among the patients using the suicide rates of the general Swedish population as a reference. In total, 21 patients committed suicide during follow-up, compared to the predicted 3.6 suicides. Thus, we noted an almost 6-fold increased risk for suicide among ALS patients [SMR 5.8, 95% confidence interval (CI) 3.6–8.8]. Patients who committed suicide were, on average, around 7 years younger at the time of their first period of hospitalization than patients who did not commit suicide. The highest relative risk for suicide was observed within the first year after the patient's first period of hospitalization (SMR 11.2, 95% CI 5.8–19.6). After that, the relative risks decreased with time after hospitalization (P-value for trend = 0.006), but remained elevated 3 years later. The relative risks of suicide among ALS patients did not show a clear trend over time in contrast to the decreasing trend of relative risks for suicide among patients with cancer during the same period. Patients with ALS are at excess risk of suicide in Sweden and the relative risk is higher during the earlier stage of the disease.


Key Words: amyotrophic lateral sclerosis; suicide; cohort study; relative risk


Abbreviations: ALS, amyotrophic lateral sclerosis; SMR, standardized mortality ratio; CI, confidence interval; ICD, International Classification of Diseases

Received January 30, 2008. Revised May 26, 2008. Accepted June 30, 2008.

http://brain.oxfordjournals.org/cgi/...short/awn161v1