Clinical Factors Associated with Inadequate Treatment Response to Methotrexate among Patients with Rheumatoid Arthritis in a Tertiary Referral Hospital

Abstract

Objective. The study aimed to determine patient-related factors associated with inadequate treatment response of patients with rheumatoid arthritis (RA) to methotrexate (MTX).

Methodology. We reviewed the medical records of patients with RA seen at the rheumatology outpatient clinic of Philippine General Hospital; dichotomized into those with adequate and inadequate treatment response to MTX. Clinical data including age, gender, comorbidities, smoking status, tender joint counts, disease activity score-28 (DAS28), and rheumatoid factor (RF) positivity were compared between the two groups. We used univariate binary logistic regression to determine whether these clinical factors were significantly associated with inadequate treatment response.

Results. Majority (47/77 or 61%) of patients have inadequate treatment response to MTX. There were no significant differences between the two study groups in terms of age, tender joint count, DAS28, sex, smoking status and RF positivity. These factors also failed to show significant association with inadequate treatment response.

Conclusion. Age, sex, smoking status, duration of disease, initial DAS28, RF positivity and tender joint counts are not significantly associated with inadequate treatment response. A larger sample size is needed to estimate the prevalence of inadequate treatment response to MTX and derive a predictive model for treatment response.