Objective To determine the effectiveness of a patient-initiated disease-modifying antirheumatic drugs (DMARD) self-monitoring service for people with rheumatoid (RA) or psoriatic arthritis (PsA) on methotrexate.

Methods A two-arm, single-centre, randomised controlled trial assessing superiority in relation to healthcare use, clinical and psychosocial outcomes. Participants were 100 adults with either RA or PsA on a stable dose of methotrexate, randomly assigned to usual care or the patient-initiated service. Intervention participants were trained how to understand and interpret their blood tests and use this information to initiate care from their clinical nurse specialist (CNS). The primary outcome was the number of outpatient visits to the CNS during the trial period. Differences between groups were analysed using Poisson regression models. Secondary outcomes were collected at baseline and after the third and sixth blood tests. Disease activity was measured using either the Disease Activity Score in 28 joints or Psoriatic Arthritis Response Criteria (PsARC), pain and fatigue using a visual numeric scale and the Health Assessment Question-II, Hospital Anxiety and Depression Scale and SF12 were completed to assess disability, mood and quality of life, respectively. Differences between groups over time on secondary outcomes were analysed using multilevel models.

Results The patient-initiated DMARD self-monitoring service was associated with 54.55% fewer visits to the CNS (p<0.0001), 6.80% fewer visits to the rheumatologist (p=0.23) and 38.80% fewer visits to the general practitioner (p=0.07), compared with control participants. There was no association between trial arm and any of the clinical or psychosocial outcomes.

Conclusions The results suggest that a patient-initiated service that incorporates patients’ self-monitoring DMARD therapy can lead to significant reductions in healthcare use, while maintaining clinical and psychosocial well-being.

Trial registration number ISRCTN21613721.