Using additive and relative hazards to quantify colorectal survival inequalities for patients with a severe psychiatric illness

Colorectal cancer mortality in persons with severe mental illness: a scoping review with meta-analyses of observational studies

BACKGROUND AND PURPOSE

Persons with severe mental illnesses (SMIs) have reduced participation in colorectal cancer (CRC) screening programs, higher odds of advanced stage at diagnosis, and are less likely to receive adequate treatment than the general population. It remains unclear to what extent these factors impact CRC outcomes for persons with SMI. The aim of this scoping review was to describe and quantify CRC mortality for persons with SMI compared with the general population.

PATIENTS/MATERIALS AND METHODS

We followed the JBI Manual for Evidence Synthesis and PRISMA guidelines in a systematic search of four databases from inception until April 29th, 2024. We included studies that provided CRC mortality estimates for adults with preexisting clinical diagnosis of SMI. We synthesized the results descriptively and pooled the data to estimate the magnitude of the associations.

RESULTS

Twenty-four original studies were identified with a total of 16.4 million persons. Most studies reported increased CRC mortality for persons with SMI compared with persons without SMI. The meta-analysis demonstrated a 25% increased CRC mortality for persons with SMI (e.g. pooled hazard ratio 1.25; 95% confidence interval 1.13 to 1.39; n = 13,178,161).

INTERPRETATION

The evidence points consistently to an increased CRC mortality for persons with SMI compared with persons without SMI. Furthermore, this evidence supports the idea that persons with SMI are a heterogenous population, and as such, any future initiatives to improve CRC outcomes for persons with SMI would warrant a tailored approach to potentiate individual resources, to mitigate stigma and structural discrimination.

Access to symptom screening and severe symptom risk among cancer patients with major mental illness

INTRODUCTION

Cancer symptom screening has the potential to improve cancer outcomes, including reducing symptom burden among patients with major mental illness (MMI). We determined rates of symptom screening with the Edmonton Symptom Assessment System (ESAS-r) and risk of severe symptoms in cancer patients with MMI.

METHODS

This retrospective cohort study used linked administrative health databases of adults diagnosed with cancer between 2007 and 2020. An MMI was measured in the 5 years prior to cancer diagnosis and categorized as inpatient, outpatient, or no MMI. Outcomes were defined as time to first ESAS-r screening and time to first moderate-to-severe symptom score. Cause-specific and Fine and Gray competing events models were used for both outcomes, controlling for age, sex, rural residence, year of diagnosis and cancer site.

RESULTS

Of 389,870 cancer patients, 4049 (1.0%) had an inpatient MMI and 9775 (2.5%) had an outpatient MMI. Individuals with inpatient MMI were least likely to complete an ESAS-r (67.5%) compared to those with outpatient MMI (72.3%) and without MMI (74.8%). Compared to those without MMI, individuals with an inpatient or outpatient MMI had a lower incidence of symptom screening records after accounting for the competing risk of death (subdistribution Hazard Ratio 0.77 (95% CI 0.74-0.80) and 0.88 (95% CI 0.86-0.90) respectively). Individuals with inpatient and outpatient MMI status consistently had a significantly higher risk of reporting high symptom scores across all symptoms.

CONCLUSIONS

Understanding the disparity in ESAS-r screening and management for cancer patients with MMI is a vital step toward providing equitable cancer care.

Agreement between individual and neighborhood income measures in patients with colorectal cancer in Canada

INTRODUCTION

With increasing interest in income-related differences in cancer outcomes, accurate measurement of income is imperative. Misclassification of income can result in wrong conclusions as to the presence of income inequalities. We determined misclassification between individual- and neighborhood-level income and their association with overall survival among colorectal cancer (CRC) patients.

METHODS

The Canadian Census Health and Environment Cohorts were used to identify CRC patients diagnosed from 1992 to 2017. We used neighborhood income quintiles from Statistics Canada and created individual income quintiles from the same data sources to be as similar as possible. Agreement between individual and neighborhood income quintiles was measured using cross-tabulations and weighted kappa statistics. Cox proportional hazards and Lin semiparametric hazards models were used to determine the effects of individual and neighborhood income independently and jointly on survival. Analyses were also stratified by rural residence.

RESULTS

A total of 103 530 CRC patients were included in the cohort. There was poor agreement between individual and neighborhood income with only 17% of respondents assigned to the same quintile (weighted kappa = 0.18). Individual income had a greater effect on relative and additive survival than neighborhood income when modeled separately. The interaction between individual and neighborhood income demonstrated that the most at risk for poor survival were those in the lowest individual and neighborhood income quintiles. Misclassification was more likely to occur for patients residing in rural areas.

CONCLUSION

Cancer researchers should avoid using neighborhood income as a proxy for individual income, especially among patients with cancers with demonstrated inequalities by income.