Background

We compared the rate of colorectal cancer surgery between indigenous and non-indigenous patients controlling for differences in demographic and clinical characteristics.

Methods

The proportion of patients who underwent colorectal cancer surgery was estimated for 242 indigenous and 23,925 non-indigenous Queensland residents diagnosed with colorectal cancer between 2001 and 2010. The relative likelihood of surgery in the two groups was compared through a modified Poisson regression model with robust error variance controlling for age, sex, cancer primary site, metastatic disease, and comorbidities.

Results

Compared to non-indigenous patients, indigenous colorectal cancer patients were younger (median age 60 yrs vs 70 yrs) and had higher proportion of females (51% vs 45%), cancers of the rectum (42% vs 32%), and patients with comorbidities (45% vs 32%). Overall colorectal cancer surgery rates were 87% and 91% for indigenous and non-indigenous patients respectively. When adjusted for demographic and clinical characteristics, the relative likelihood (risk ratio) of cancer surgery in indigenous patients was 0.95 (95% confidence interval: 0.91-1.00, p=0.041) compared to non-indigenous patients.

Conclusion

Colorectal cancer surgery rates are only marginally lower in indigenous compared to non-indigenous patients. Other measures of health care access and quality of care should be investigated to account for poorer cancer outcomes among indigenous people.