Subcutaneous Anti-tnf-αlpha In Rheumatoid Arthritis: Analyze The Correlation Between Objective Measures Of Disease Activity And Safety And A Subjective Measure Such As Patient Beliefs About A Medicine
Subcutaneous Anti-tnf-αlpha In Rheumatoid Arthritis: Analyze The Correlation Between Objective Measures Of Disease Activity And Safety And A Subjective Measure Such As Patient Beliefs About A Medicine
It can be assumed that there is a link between what the patient feels and thinks about his medication and objective measures of disease activity and safety.
A total of 500 subjects will provide 80% power to test the hypothesis that the absolute value of the correlation between two measures (e.g., BMQ Necessity and DAS28) is ≤ 0.3 (i.e., H0:│r│ ≤ 0.3 ) versus the alternative that it is > 0.3 (i.e., H1:│r │ > 0.3 ) assuming the absolute value of the true correlation is 0.40. A total of 500 will be enrolled to allow for approximately 5% being lost from analysis due to lack of post baseline data.
The Pearson method will be used for correlation between the BMQ total score for Necessity and the DAS28 and between the BMQ total score for Concern and DAS28. The Spearman rank method will be used for correlation between the BMQ total scores and Safety. For these latter analyses, subjects will be classified into one of 3 safety categories: (1) No AEs, (2) Non-serious AEs, (3) Serious AEs. 95% confidence intervals for the correlations will be provided.
Inclusion Criteria:
Patients with RA on stable therapy defined as:
Etanercept: 1x50 mg/week or 2x25mg/week for at least 1 consecutive year. Adalimumab: 1x40 mg every other week for at least 1 consecutive year. Oral corticosteroids: stable doses for ≥ 12 weeks before baseline Methotrexate: stable doses for ≥ 12 weeks before baseline Other DMARD's: stable doses for ≥ 12 weeks before baseline
Exclusion Criteria:
Participation in other clinical or observational trials.