title: Comparison of the Charlson Comorbidity Index derived from self-report and medical record review in Asian patients with rheumatic diseases.
abstract: The aim of the study was to compare the agreement between self-report Charlson Comorbidity Index (SR-CCI) and the medical record-based CCI (MR-CCI) and to examine the impact of both instruments on health-related quality of life (HRQoL) amongst Asian patients with rheumatic diseases. This cross-sectional study surveyed a convenience sample of patients seen at rheumatology specialty outpatient clinics. Patients completed the SR-CCI and Short Form 36, while two research assistants completed the MR-CCI. Item-level agreement between the SR-CCI and MR-CCI was evaluated using kappa coefficients. Adjusted linear regression models evaluated the independent effect of the SR-CCI/MR-CCI on HRQoL. The study included 301 patients (median age 51, range 21-79, 61.5 % female, 68.8 % Chinese, 17.6 % Indian, 6.0 % Malay). Kappa statistics for cerebrovascular disease (0.433), chronic pulmonary disease (0.509), connective tissue disease/rheumatoid arthritis (0.506), ulcer disease (0.461), and tumour (0.541) reflected moderate agreement between the SR-CCI and MR-CCI (all p < 0.0001). There was substantial agreement in the reporting of diabetes (0.764, p < 0.0001) but poor/fair agreement for that of myocardial infarction (0.359, p < 0.0001) and diabetes with end-organ damage (0.189, p = 0.0002). Increases in SR-CCI were associated with significant reductions in both physical (β coefficient -2.56, p < 0.0001) and mental HRQoL (β coefficient -1.24, p = 0.044). However, such associations were not observed with the MR-CCI. The SR-CCI demonstrated moderate concordance with the MR-CCI, and the SR-CCI but not MR-CCI scores were associated with lower HRQoL. Assessment of comorbidities amongst rheumatology patients remains complex, and more efficient methods of quantifying these conditions are needed for clinical and research purposes.
authors.affiliation: Department of Pharmaceutical Health Services Research, University of Maryland Baltimore, Baltimore, MD, USA.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Ng
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, 20 College Road, Singapore, Singapore.|Duke-NUS Graduate Medical School, Singapore, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Andrea Hsiu Ling
authors.initials: AH
authors.lastname: Low
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, 20 College Road, Singapore, Singapore. julian.thumboo@sgh.com.sg.|Duke-NUS Graduate Medical School, Singapore, Singapore. julian.thumboo@sgh.com.sg.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. julian.thumboo@sgh.com.sg.
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D002561:Cerebrovascular Disorders / Q000150:complications; D003240:Connective Tissue Diseases / Q000150:complications; D059026:Diagnostic Self Evaluation; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000150:complications; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D011788:Quality of Life; D012216:Rheumatic Diseases / Q000150:complications / Q000175:diagnosis*; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Comorbidity; Quality of life; Rheumatic disease; Rheumatology; Self-report