Insurance Status Predicts Surgical Outcomes for Patients with Colorectal Cancer

Abstract & Commentary

Synopsis: Patients without insurance have been reported to have less satisfactory health outcomes, and this has been attributed to a number of factors including access to health care and a greater burden of comorbid conditions. In the current retrospective analysis, short-term outcomes including surgical complications and in-hospital mortality were greater for uninsured or Medicaid recipient colorectal cancer patients (aged, 40-64 years) compared with those with private insurance. By multivariate analysis, insurance status was found to be an independent predictor of short-term outcome with regard to perioperative complications and mortality.

Source: Kelz RR, et al. Cancer. 2004:101;2187-2194.

For a number of reasons, uninsured or underinsured patients might be at increased risk for negative health outcomes. These include impaired access to health care, delayed treatment, and the receipt of substandard care. With regard to surgical outcomes, it is also quite possible that poor outcomes may be related to an increased disease burden or a greater likelihood of emergent, rather than elective, operative intervention. In the current study, Kelz and associates at the University of Pennsylvania examined associations between insurance provider and short-term surgical outcomes after surgery for colorectal cancer and evaluated the extent to which two risk factors (comorbid disease and admission type) might explain any observed association.

For this, Kelz and colleagues conducted a nationally representative retrospective cohort study of 13,415 adults ages 40-64 years who were admitted for surgery for colorectal carcinomas throughout the > 1000 hospitals that participated in the Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) National Inpatient Study (NIS) releases 6 and 7, from 1997 and 1998.

To arrive at this cohort, data from 169,206 subjects who were admitted for colorectal surgical procedures of which 56,493 had a diagnosis of nonmetastatic carcinoma of the colon or rectum were examined. Of these, 15,183 were in the 40-64 year old (non-Medicare) age group. Incomplete or missing data required the exclusion of 1776 patients, thereby resulting in the study population of 13,415. Of these, approximately 85% had private insurance, 6% were uninsured and 9% were recipients of Medicaid. Approximately 14% of the admissions were classified as emergent and a comorbid illness was identified in 57% of patients. As expected, a lack of insurance and Medicaid receipt were associated with increased comorbidity and more emergent admissions compared with patients with private insurance (P < 0.0001).

By univariate analysis, it was clear that insurance status was associated with adverse surgical outcomes. It was also clear that there were several risk factors more prevalent among patients without private insurance (emergent admission type, comorbidity, and advanced age) and the presence of any of these was associated with higher rates of both postoperative complications and mortality. Accordingly, multivariate and logistic regression models were developed to describe the correlations between insurance status and the risks of postoperative complications or postoperative death after adjustment for socio-economic factors, comorbid conditions, and admission type. In this analysis, uninsured and Medicaid recipients were found to have more emergent admissions and a greater comorbidity burden compared with those with private health insurance. Patients without private health insurance had higher rates of postoperative complications and in-hospital death compared with those patients with private insurance. Emergent admission type, high comorbid burden (3+) and several specific comorbid conditions were associated with a higher odds ratio of postoperative complications in this analysis for the population as a whole (ie, independent of insurance status). However, after adjusting for these factors, patients with Medicaid were found to be 22% more likely to develop a complication during their hospital admission (odds ratio [OR] of 1.22; 95% confidence interval [CI], 1.06-1.40) and 57% more likely to die postoperatively (OR of 1.57; 95% CI, 1.01-2.42) compared with patients with private insurance.

Comment by William B. Ershler, MD

In general, it has been widely acknowledged that uninsured and underinsured patients have less satisfactory outcomes when compared to those with private insurance1-4 and this is frequently attributed to fragmented care, poor access to prevention and screening, delay in diagnosis, more advanced disease at presentation and the presence of a greater burden of comorbid conditions. In the current analysis, however, patients with clinically apparent non-metastatic disease were found to have more adverse short-term outcomes on the basis of insurance status alone (ie, after controlling for these other factors in a multivariate model). Explanations for this may relate to a tendency for uninsured to receive fragmented medical care, often in emergency departments and possibly to be referred to less experience surgeons for treatment. It is also possible that within the current cohort, uninsured patients had more locally-advanced disease, thereby increasing the complication and perioperative mortality rate; a variable for which data was not available in the current analysis. Nonetheless, as we currently address the crisis in health care, and keeping in mind that approximately 25% of the US population is uninsured,5 the implications are sobering but intuitive. Patients without health insurance have a greater risk of receiving substandard care and in a specific disease (colorectal cancer) and procedure (surgical resection) focused retrospective analysis such as this, the difference in outcome is quite apparent.


1. Roetzheim RG, et al. J Natl Cancer Inst. 1999;91: 1409-1415.

2. Roetzheim RG, et al. Am J Public Health. 2000;90: 1746-1754.

3. Sada M, et al. J Am Coll Cardiol. 1998;31:1474-1480.

4. McDavid K, et al. Arch Intern Med. 2003;163: 2135-2144.

5. Centers for Disease Control and Prevention, National Center for Health Statistics. National Health Inventory Survey. Available from URL:

William B. Ershler, MD, INOVA Fairfax Hospital Cancer Center, Fairfax, VA; Director, Institute for Advanced Studies in Aging, Washington, DC, is Editor for Clinical Oncology Alert.