Schizophrenia Associated With Years of Life Lost

A reduction in suicide risk and improved quality of care could have notable effects on years of potential life lost to schizophrenia.
A reduction in suicide risk and improved quality of care could have notable effects on years of potential life lost to schizophrenia.

A systematic review and meta-analysis has found that schizophrenia was associated with a weighted average of 14.5 years of potential life lost, and that this substantial amount seems not to have lessened over time.

Darsten Hjorthøj, PhD, from the Copenhagen University Hospital in Denmark, and colleagues searched MEDLINE, PsycINFO, Embase, Cinahl, and Web of Science for published studies on years of potential life lost and life expectancy in schizophrenia. They found 11 studies in 13 publications that included 247,603 patients in all inhabited continents except South America (Africa n=1, Asia n=1, Australia n=1, Europe n=7, and North America n=3).

They combined the data in meta-analyses as weighted averages and conducted subgroup analyses for sex, geographical region, timing of publication, and risk of bias (estimated with the Newcastle-Ottawa Scale).

The researchers found that schizophrenia was associated with a weighted average of 14.5 years of potential life lost (95% CI 11.2-17.8).

They also found that:

  • Loss of life was greater in men at 15.9 years (range 13.8-18.0 years) than in women at 13.6 years (range 11.4-15.8 years)
  • Loss of life was least in the study in Asia and greatest in the study in Africa
  • Life expectancy was lowest in Asia and Africa
  • The overall weighted average life expectancy was 64.7 years (95% CI 61.1-71.3)
  • The overall weighted average life expectancy was lower in men at 59.9 years (95% CI 55.5-64.3) than in women at 67.6 years (95% CI 63.1-72.1)

“In the studies we assessed, schizophrenia was associated with at least 13 to 15 years of potential life lost, with men losing more years to schizophrenia than women,” the investigators wrote. “We found no indication that this loss had lessened over time, which highlights the importance of developing and implementing interventions and initiatives to reduce the excess mortality.”

The researchers also noted that their findings are consistent with existing literature about premature death in schizophrenia, which has several explanations. Several studies have shown an increased prevalence of somatic disorders such as cardiovascular disease and diabetes in patients with schizophrenia compared with the general population.2-5 There could be several explanations for this, including the metabolic side effects from second-generation anti-psychotics,6-8 increased rates of smoking and use of illicit substances in schizophrenia,9-12 and increased rates of poor diets and sedentary lifestyles.13,14 Some research has also suggested a shared genetic disposition for metabolic syndrome or cardiovascular disease and schizophrenia.15,16 The risk of suicide is also increased by as much as 22-fold in people with schizophrenia compared with the general population, especially within 1 year of the first hospital admission.17

“Consequently, a reduction in suicide risk and improved quality of care could have notable effects on years of potential life lost to schizophrenia,” the researchers wrote.

Limitations

  • The meta-analysis was only based on 11 studies
  • All of the included studies used International Classification of Diseases (ICD) criteria to diagnose schizophrenia, so the researchers could not explore whether life expectancy differs according to diagnostic system
  • Most studies did not report standard errors (SEs) or CIs for years of potential life lost or life expectancy, so the researchers had to extrapolate the pooled SE. This could have led to over- or underestimation of true SEs
  • All participants in the studies had sought treatment, so the researchers could not examine differences in life lost based on whether treatment was sought or not


References

  1. 1. Hjorthøj C, Stürup AE, McGrath JJ, Nordentoft M. Years of life lost and life expectancy in schizophrenia: a systematic review and meta-analysis [published online February 21, 2017]. The Lancet. doi:10.1016/S2215-0366(17)30078-0
  2. Laursen TM, Munk-Olsen T, Vestergaard M, et al. Life expectancy and cardiovascular mortality in persons with schizophrenia. Curr Opin Psychiatry. 2012;25:83-88.
  3. Azad MC, Shoesmith WD, Al Mamun M, et al. Cardiovascular diseases among patients with schizophrenia. Asian J Psychiatr. 2016;19:28-36.
  4. Stubbs B, Vancampfort D, De Hert M, Mitchell AJ. The prevalence and predictors of type two diabetes mellitus in people with schizophrenia: a systematic review and comparative meta-analysis. Acta Psychiatr Scand. 2015;132:144-157.
  5. Suvisaari J, Keinänen J, Eskelinen S, Mantere O. Diabetes and schizophrenia. Curr Diab Rep. 2016;16:16.
  6. Rummel-Kluge C, Komossa K, Schwarz S, et al. Head-to-head comparisons of metabolic side effects of second generation antipsychotics in the treatment of schizophrenia: a systematic review and meta-analysis. Schizophr Res. 2010;123:225-233.
  7. Young SL, Taylor M, Lawrie SM. “First do no harm”: a systematic review of the prevalence and management of antipsychotic adverse effects. J Psychopharmacol. 2015;29:353-362.
  8. Leung JYT, Barr AM, Procyshyn RM, Honer WG, Pang CCY. Cardiovascular side-effects of antipsychotic drugs: the role of the autonomic nervous system. Pharmacol Ther. 2012;135:113-122.
  9. Poirier MF, Canceil O, Baylé F, et al. Prevalence of smoking in psychiatric patients. Prog Neuropsychopharmacol Biol Psychiatry. 2002;26: 529-537.
  10. Lasser K, Boyd JW, Woolhandler S, Himmelstein DU, McCormick D, Bor DH. Smoking and mental illness: a population-based prevalence study. JAMA 2000; 284:2606-2610.
  11. Toftdahl NG, Nordentoft M, Hjorthøj C. Prevalence of substance use disorders in psychiatric patients: a nationwide Danish population-based study. Soc Psychiatry Psychiatr Epidemiol 2016;51:129-140.
  12. Hjorthøj C, Østergaard MLD, Benros ME, et al. Association between alcohol and substance use disorders and all-cause and cause-specific mortality in schizophrenia, bipolar disorder, and unipolar depression: a nationwide, prospective,register-based study. Lancet Psychiatry. 2015;2:801-808.
  13. Stubbs B, Williams J, Gaughran F, Craig T. How sedentary are people with psychosis? A systematic review and meta-analysis. Schizophr Res. 2016;171:103-109.
  14. Dipasquale S, Pariante CM, Dazzan P, Aguglia E, McGuire P, Mondelli V. The dietary pattern of patients with schizophrenia: a systematic review. J Psychiatr Res. 2013;47:197-207.
  15. Malan-Müller S, Kilian S, van den Heuvel LL, et al. A systematic review of genetic variants associated with metabolic syndrome in patients with schizophrenia. Schizophr Res. 2016;170:1-17.
  16. Andreassen OA, Djurovic S, Thompson WK, et al. Improved detection of common variants associated with schizophrenia by leveraging pleiotropy with cardiovascular-disease risk factors. Am J Hum Genet. 2013;92:197-209.
  17. Nordentoft M, Wahlbeck K, Hällgren J, et al. Excess mortality, causes of death and life expectancy in 270,770 patients with recent onset of mental disorders in Denmark, Finland and Sweden. PLoS One. 2013;8:e55176.
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