Importance: The comorbid conditions of patients with cancer affect treatment decisions, which in turn affect survival and health-related quality-of-life outcomes. Comparative effectiveness research studies must account for these conditions via medical record abstraction or patient report.
Objective: To examine the agreement between medical records and patient reports in assessing comorbidities.
Design, setting, and participants: Patient-reported information and medical records were prospectively collected as part of the North Carolina Prostate Cancer Comparative Effectiveness & Survivorship Study, a population-based cohort of 881 patients with newly diagnosed localized prostate cancer enrolled in the North Carolina Central Cancer Registry from January 1, 2011, through June 30, 2013. The presence or absence of 20 medical conditions was compared based on patient report vs abstraction of medical records.
Main outcomes and measures: Agreement between patient reports and medical records for each condition was assessed using the κ statistic. Subgroup analyses examined differences in κ statistics based on age, race, marital status, educational level, and income. Logistic regression models for each condition examined factors associated with higher agreement.
Results: A total of 881 patients participated in the study (median age, 65 years; age range, 41-80 years; 633 white [71.9%]). In 16 of 20 conditions, there was agreement between patient reports and medical records for more than 90% of patients; agreement was lowest for hyperlipidemia (68%; κ = 0.36) and arthritis (66%; κ = 0.14). On multivariable analysis, older age (≥70 years old) was significantly associated with lower agreement for myocardial infarction (odds ratio [OR], 0.31; 95% CI, 0.12-0.80), cerebrovascular disease (OR, 0.10; 95% CI, 0.01-0.78), coronary artery disease (OR, 0.37; 95% CI, 0.20-0.67), arrhythmia (OR, 0.44; 95% CI, 0.25-0.79), and kidney disease (OR, 0.18; 95% CI, 0.06-0.52). Race and educational level were not significantly associated with κ in 18 of 19 modeled conditions.
Conclusions and relevance: Overall, patient reporting provides information similar to medical record abstraction without significant differences by patient race or educational level. Use of patient reports, which are less costly than medical record audits, is a reasonable approach for observational comparative effectiveness research.