Why do psychiatric patients have higher cancer mortality rates when cancer incidence is the same or lower?

Kisely, Steve, Forsyth, Simon and Lawrence, David (2015) Why do psychiatric patients have higher cancer mortality rates when cancer incidence is the same or lower?. Australian and New Zealand Journal of Psychiatry, 50 3: 254-263. doi:10.1177/0004867415577979


Author Kisely, Steve
Forsyth, Simon
Lawrence, David
Title Why do psychiatric patients have higher cancer mortality rates when cancer incidence is the same or lower?
Journal name Australian and New Zealand Journal of Psychiatry   Check publisher's open access policy
ISSN 0004-8674
1440-1614
Publication date 2015-03-31
Sub-type Article (original research)
DOI 10.1177/0004867415577979
Volume 50
Issue 3
Start page 254
End page 263
Total pages 10
Place of publication London, United Kingdom
Publisher Sage Publications
Collection year 2016
Language eng
Formatted abstract
Objective: Studies of overall cancer incidence and mortality in psychiatric patients have had mixed results. Some have reported lower than expected cancer incidence or mortality, while others have found no association or an increased risk depending on sample, psychiatric diagnosis, cancer site and methodology. Few studies have compared cancer incidence and mortality using the same population and methodology.

Method: A population-based record-linkage analysis to compare cancer incidence and mortality in psychiatric patients with that for the general Queensland population, using an historical cohort to calculate age- and sex-standardised rate ratios and hazard ratios. Mental health records were linked with cancer registrations and death records from 2002 to 2007.

Results:
There were 89,992 new cancer cases, of which 3349 occurred in people with mental illness. Cancer incidence was the same as the general population for most psychiatric disorders. Rates were actually lower for dementia (hazard ratio=0.77; 95% confidence interval=[0.67, 0.88]) and schizophrenia (hazard ratio=0.84; 95% confidence interval=[0.72, 0.98]). By contrast, mortality was increased in psychiatric patients (hazard ratio=2.27; 95% confidence interval=[2.15, 2.39]) with elevated hazard ratios for all the main psychiatric diagnoses.

Conclusions: Lifestyle, such as alcohol or tobacco use, would not explain our findings that people with mental illness are no more likely than the general population to develop cancer but more likely to die of it. Other factors may be the difficulty in differentiating medically explained and unexplained symptoms, greater case fatality or inequity in access to specialist procedures. The study highlights the need for improved cancer screening, detection and intervention in this population.
Keyword Medical record linkage
Cancer
Mental health
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Public Health Publications
School of Medicine Publications
 
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Created: Thu, 17 Dec 2015, 14:21:27 EST by Simon Forsyth on behalf of School of Public Health