Increasingly shorter life spans for bipolar and schizophrenia

Well having moaned about the lack of evidence that people with mental illness are dying unnecessarily early I then found several articles about just that topic so here’s what I found.

http://archpsyc.ama-assn.org/cgi/content/full/64/10/1123 A Systematic Review of Mortality in Schizophrenia. Is the Differential Mortality Gap Worsening Over Time? Sukanta Saha, MSc, MCN; David Chant, PhD; John McGrath, MD, PhD, FRANZCP Arch Gen Psychiatry. 2007;64(10):1123-1131

and also this article

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3172324/pdf/bmj.d5422.pdf?tool=pmcentrez Mortality after hospital discharge for people with schizophrenia or bipolar disorder: retrospective study of linked English hospital episode statistics, 1999-2006.

 Which are both quoted in this article. http://psychcentral.com/lib/2012/premature-death-rates-rising-in-schizophrenia-bipolar-patients/ Premature Death Rates Rising in Schizophrenia, Bipolar Patients By Jane Collingwood

They all basically state the same thing though for convenience I am going to quote the second one which also has the added bonus of using UK figures however there are one or two things in the others that I will refer to later. So from their results;

Age and sex standardised mortality ratios for death in year after hospital discharge between 1999 and 2006 by principal psychiatric diagnosis and specific cause of death

Basically that means that these when the rate of expected numbers of deaths due to a cause is equal to that in the normal population the value will be 1. Smaller than one and there are fewer deaths (for instance say the value is 0.5 then the ratio is 1 over two so there are twice as many deaths in the normal population as there were in this sample of patients) due to that cause, Larger there are more (equally if the value is 2 then there are twice as many deaths in the patient population than in the normal population)

Bipolar disorder (ICD-10, code F31)

Year of discharge	Circulatory disease*	Cancer†	Respiratory disease‡	Accidents§	Suicide and undetermined intent
1999	1.6	0.4	3.0	6.8	13.5
2000	1.4	0.7	2.5	5.2	21.2
2001	1.6	0.5	3.7	4.7	24.8
2002	1.8	0.8	5.7	4.9	20.2
2003	1.8	0.9	5.0	4.0	27.7
2004	1.8	0.5	4.9	4.8	32.1
2005	2.1	0.6	4.6	5.0	29.5
2006	2.5	0.6	5.8	6.6	19.8

Schizophrenia (ICD-10, codes F20-29)

Year of discharge	Circulatory disease	Cancer†	Respiratory disease	Accidents	Suicide and undetermined intent
1999	1.6	0.8	3.1	6.5	19.5
2000	2.0	1.0	3.5	7.5	19.6
2001	1.6	0.9	4.0	5.8	21.8
2002	1.9	1.0	4.4	4.2	17.8
2003	2.5	1.1	5.3	5.3	23.3
2004	2.2	1.1	5.6	6.8	24.7
2005	2.4	1.1	6.0	8.3	24.0
2006	2.5	1.3	4.7	6.3	20.9

As you can see for suicide and undetermined intent the figures are large which you would kind of expect although would not wish for. Equally the number of deaths due to accidents is high which correlates to these people taking more risks than the average person, which again could be expected but not wished for. However the figures that do surprise people are those deaths due to treatable illnesses such as respiratory or circulatory and are seemingly put down to lack of good treatment ie medical intervention, or a consequence of the drug treatments these patients undergo to control their mental health problems. I am not entirely sure how they are coming to these conclusions and unfortunately the papers themselves do not give much explanation.

You might wonder why the rates of cancer are lower than the national population however this might just be because this is a small sample size compared the whole population however it is interesting to ask whether any of the findings are significant statistically as this would point to there being a distinct difference between people having a mental illness and them dying of a particular cause. The paper does not state any test of significance for cause of death, which is probably due to the numbers being so small in this sample set. However I think it can be safely assumed that death by suicide or undetermined intent is significantly different from the population.

So is the mortality gap widening over time?

So from their results section they state (confidence intervals in brackets)

...standardised mortality ratios for people with schizophrenia increased from 1.6 (1.5 to 1.8) in people discharged in 1999 to 2.2 (2.0 to 2.4) in people discharged in 2006. The Poisson test for trend confirmed that the trend in risk of mortality was significant (P<0.001). For people with bipolar disorder, standardised mortality ratios increased from 1.3 (1.1 to 1.6) in people discharged in 1999 to 1.9 (1.6 to 2.2) in people discharged in 2006 (table 3⇓). The Poisson test of trend had results of borderline significance (P=0.06).

So for patient who have been hospitalised it appears the mortality gap did widen during this study period, however what proportion of the total number of sufferers that is and whether this will continue is unclear.

What is also unclear is why this it happened?

There are suggestions

·         that the new medications may be partly to blame

·         that there may be neglect from the medical profession

·         personal neglect of diet and fitness

·         bad habits such as alcohol, drugs, smoking may be of concern

but due to the confounding factors separating any of these from each other is not possible with the data collected so far.