Osteoarthritis (OA) has been identified as the disease with the highest rate of comorbidities, which may increase the likelihood of disability. The AMICA study evaluated how the presence of a coexistent disease and/or its chronic pharmacological treatment influenced the prescription of pharmacological and nonpharmacological therapy in patients with OA.
The 2764 general practitioners (GPs) and 316 specialists (98 rheumatologists, 166 orthopedic surgeons, 52 physical medicine specialists) participating in the study were asked to enroll 10 consecutive patients with OA diagnosed according to the American College of Rheumatology clinical criteria. Information was collected regarding demographics, the clinical characteristics of OA, and previous diagnostic and therapeutic interventions. Pain intensity was assessed using a 100-mm visual analog scale (VAS); the patients were also asked to report on their quality of life and joint function, as well as the presence of any concomitant disease and/or therapy. The influence of comorbidities on the quality of life, pain, and drug prescription was evaluated.
A total of 29,132 evaluable patients was observed (25,589 recruited by GPs and 3543 by specialists). The most frequent comorbidities were hypertension (52%), osteoporosis (21%), type II diabetes mellitus (15%), and chronic obstructive pulmonary disease (12%); myocardial infarction and/or angina pectoris were present in 6% and peptic ulcer was present in 5%. Comorbidities were more frequent in older patients and, except in the case of hypertension, were closely related to more intense pain and a decreased quality of life; they were also generally associated with worsened joint function. The presence of peptic ulcer was associated with a reduction in the prescription of nonsteroidal antiinflammatory drugs (NSAIDs) (odds ratio (OR) 0.61; confidence intervals (CI) 0.53 to 0.69) and the more frequent use of Coxibs (OR 1.15; CI 1.03 to 1.28) and simple analgesics (OR 1.42; CI 1.26 to 1.61), as well as with greater use of physical therapy. Hypertension was associated with a reduction in the prescription of physical therapy. NSAIDs and Coxibs were less frequently prescribed if the patients were on anticoagulant therapy (NSAIDs: OR 0.86; CI 0.70 to 1.06; Coxibs: OR 0.77; CI 0.64 to 0.93). Gastroprotective therapy was more frequently used in patients treated with NSAIDs, Coxibs, and analgesics, with GPs giving greater preference to proton pump inhibitors than specialists.
Comorbidities decrease the quality of life and worsen the joint function in OA patients. Comorbidities and their treatment generally do not influence the physician's choice of OA treatment, with the exception of peptic ulcer and anticoagulant therapy, both of which were associated with a reduction in the prescription of antiinflammatory drugs. There was a preferential use of Coxibs in patients with peptic ulcer, and an underuse of gastroprotective measures in OA patients treated with NSAIDs.