Co-morbidities of patients with knee osteoarthritis.

OBJECTIVES

To study the co-morbidities of general practice patients with knee osteoarthritis.

DESIGN

Cross-sectional study.

SETTING

Two private general practice clinics in Hong Kong.

PATIENTS: All patients presenting at the two clinics were screened for osteoarthritis of the knee based on American College of Rheumatology diagnostic criteria. Patients with osteoarthritis then completed a semi-instructed questionnaire.

RESULTS

A total of 455 patients were recruited into the study. Over half (56%) had knee pain plus more than three other diagnostic criteria. Almost all (95%) of the patients with osteoarthritis had no signs of inflammation at the time of screening. Their mean age was 54 years. Overall, 78% of them had at least one musculoskeletal co-morbidity and 82% had at least one non-musculoskeletal co-morbidity. On average they had 3.2 co-morbidities, of which 1.7 were musculoskeletal and 1.5 were non-musculoskeletal. Problems related to the back, upper limbs, neck, and lower limbs were the four most common musculoskeletal co-morbidities, of which neck problems were significantly more common among younger patients (55 years or below) [odds ratio for older to younger patients was 0.62; 95% confidence interval, 0.4-0.9]. The four commonest non-musculoskeletal co-morbidities were cardiovascular, gastro-intestinal, respiratory, and endocrine, of which cardiovascular diseases (odds ratio=8.76; 95% confidence interval, 5.6-13.7), endocrine problems (4.56; 2.8-7.4), and central nervous system diseases (12.74; 1.6-102.8) were significantly likely among older patients (more than 55 years).

CONCLUSION

General practitioners should be alert to the presence of co-morbidities when managing patients with osteoarthritis of the knee.