People with severe mental illness are less likely to attend cancer screening compared to those who do not have such conditions, UK researchers said.
People with severe mental illness are nearly 2.5 times more likely than those without severe mental illness to die prematurely (under the age of 75) from cancer in England, said the authors of a new study, published in the British Journal of Cancer.
They highlighted that several possible explanations for lower cancer survival in those with severe mental illness had been suggested, which included delayed help-seeking, difficulties in communication, and poorer adherence to treatment, and postulated that "lower participation in screening may be a contributing factor".
Dr Robert Kerrison, co-lead of the cancer care group at the University of Surrey, and lead author, said: "People with severe mental illness are two and a half times more likely to die prematurely from cancer than their peers. Their cancer is often diagnosed at an advanced stage, which limits the treatment options available to them. Increasing early diagnosis, through screening, could help save lives from cancer, and reduce inequalities in cancer outcomes."
Association With Specific Severe Mental Illnesses Unclear
The authors pointed out that research by Public Health England (PHE) supported their hypothesis, and reported that people with severe mental illness were "considerably less likely to participate in all three cancer screening programmes".
Compared with people who did not have severe mental illness, people with severe mental illness were 18% less likely to participate in breast screening, 20% less likely to participate in cervical screening, and 31% less likely to participate in bowel screening, they alluded.
However, the authors stressed that PHE's analysis "did not differentiate" between severe mental health conditions - such as schizophrenia and bipolar disorder - and did not explore variation among those with severe mental illness by sociodemographic characteristics.
"As such, it is not known whether specific severe mental illnesses are associated with lower participation in individual cancer screening programmes, nor whether inequalities are exacerbated by known correlates of screening participation, such as age, sex and deprivation, some of which (e.g. Black or minority ethnic group, deprivation, smoking) are also associated with higher prevalence of severe mental illness," they cautioned.
They asserted that greater understanding would enable "better targeting" of public health interventions and support for those with severe mental illness, and may help to "reduce the health inequalities" experienced by them.
Screening Participation Lowest for Those With Schizophrenia
For the study, the researchers from the University of Surrey and the Office for Health Improvement and Disparities (OHID) at the Department of Health and Social Care (DHSC) set out to verify whether inequalities in cancer screening participation persisted after controlling for additional factors that were known to be associated with screening participation. They also wanted to test for possible associations between specific severe mental illnesses, such as schizophrenia and bipolar disorder, and breast, bowel, or cervical screening participation, and to identify subgroups of individuals with severe mental illness who were least likely to participate in screening.
They analysed data from the Clinical Practice Research Datalink (CPRD) for possible associations between severe mental illness and participation in bowel screening (1.71 million eligible between March 2017 to September 2020), breast screening (1.34 million eligible between March 2016 to September 2020), and cervical screening (2.5 million eligible between March 2016 to September 2020).
The analysis, which included CPRD data on over one million people, showed that:
- Inequalities were widest for bowel cancer screening - 42.11% of people with a severe mental illness attended bowel cancer screening, compared with 58.89% of people without - followed by breast cancer screening – 48.33% vs 60.44% - and cervical cancer screening – 64.15% vs 69.72%
- Participation was lowest in those with schizophrenia in all three programmes (33.50%, 42.02%, and 54.88% for bowel, breast, and cervical screening, respectively), followed by other psychoses (41.97%, 45.57%, 61.98%), then bipolar disorder (49.94%, 54.35%, 69.69%)
- Participation was lowest among people with severe mental illness who lived in the most deprived quintile of areas (bowel, breast, cervical: 36.17%, 40.23%, 61.47%, respectively), or were of Black ethnicity (34.68%, 38.68%, 64.80%). Adults of an ethnic minority group with severe mental illness had lower participation than their White counterparts
Deeper Delving DesirableDr Ian Walker, Cancer Research UK’s executive director of policy and information, stressed that the research not only "exposes concerning barriers" to participating in cancer screening faced by people with severe mental illness, but also "crucially, shows where these disparities persist" across ethnic minority groups and in more deprived areas.
"We now need to learn more about why participation rates are lower for these individuals, so that medical professionals can tailor support and make it easier for people with severe mental conditions to attend." Dr Kerrison stressed.
Given that in England, participation in cancer screening was low among people with severe mental illness, the authors asserted that "support should be targeted" to ethnically diverse and socioeconomically deprived areas, where severe mental health illness prevalence was greatest.
The authors said that the results of the study highlighted:
- The need for qualitative research to better understand why people with severe mental illness were less likely to participate in all three cancer screening programmes, and to support the development and co-production of interventions to address the individual-level and organisational barriers to screening experienced by these groups
- Implications for policy in supporting the ambition of the NHS Long Term Plan to increase access to annual physical health checks for adults with severe mental illness
- The need for specific action to support people with schizophrenia, as well as the need for extra support for people with severe mental illness living in socioeconomically deprived and/or ethnically diverse areas
- A need for routine data linkage to allow analysis to be carried out as standard, rather than having to rely on sample data, such as CPRD
"We need to delve further into this area of research to properly understand why these gaps exist," urged Dr Walker. "It’s vital that we work with individuals and communities to build targeted interventions that ensure everyone benefits equally from programmes that diagnose cancer early and, ultimately, save lives."
The study was commissioned and funded by NHS England, through a service level agreement with the Office for Health Improvement and Disparities (OHID). RSK is supported by a Cancer Research UK Population Research Fellowship. The authors declared no conflicts of interest.