Schizophrenia Associated With Years of Life Lost

Schizophrenia was associated with 13 to 15 years of potential life lost.

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

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References

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