Scarpa 2008.

Methods	Study design: randomised, controlled trial of methotrexate plus NSAIDs vs NSAIDs alone with later addition of methotrexate Duration of study: 6 months Run‐in period: none Location: Italy Number of study centres: not reported Study setting: outpatient Withdrawals: none Dates of study: not reported
Participants	Randomised: n = 35 Group A ‐ NSAIDs alone for 3 months ‐ n = 19 Group B ‐ NSAIDs + methotrexate up‐front for 3 months ‐ n = 16 Completed: n = 35 Baseline characteristics Mean age (SD): 25.6 years (±5.7) Sex: 18 males, 17 females Mean disease duration: not reported Median pain (IQR) (VAS 100 mm) Group A ‐ 65 (23) Group B ‐ 80 (30) Median patient global assessment (IQR) (Likert 0 to 5) Group A ‐ 3.5 (1) Group B ‐ 4 (1) Median physician global assessment (IQR) (Likert 0 to 5) Group A ‐ 3 (1) Group B ‐ 4 (0) Median swollen joint count (IQR) (assumed 66) Group A ‐ 2.5 (2) Group B ‐ 2 (2) Median tender joint count (IQR) (assumed 68) Group A ‐ 3 (2) Group B ‐ 2 (2) Severity of condition: not reported Diagnostic criteria: rheumatologist‐diagnosed PsA Inclusion criteria: Patients with oligoarthritis according to the Moll and Wright criteria from Rheumatology Clinics Patients in a "sine psoriasis" subset Exclusion criteria: not reported
Interventions	Methotrexate up‐front group: methotrexate intramuscular 10 mg weekly with daily NSAID therapy at full dosage NSAID only up‐front group: NSAID therapy at full dosage for 3 months, followed by the addition of methotrexate intramuscular 10 mg weekly for a further 3 months Concomitant medications: NSAIDs at full dose Excluded medications: not reported
Outcomes	Time points: data extracted for 3 month outcomes only to allow comparison between methotrexate and NSAIDs (considered placebo) Major: Serious adverse events ‐ measured as events/no events, with events indicating harm Withdrawals due to adverse events ‐ measured as events/no events, with events indicating harm Minor: Pain (VAS 100 mm) ‐ 0 mm for no pain, 100 mm for maximum pain ‐ reported as median (IQR) Total adverse events ‐ measured as events/no events, with events indicating harm Patient global assessment (Likert 0 to 5) ‐ 0 = no disease activity; 5 = high disease activity ‐ reported as median (IQR) Physician global assessment (Likert 0 to 5) ‐ 0 = no disease activity; 5 = high disease activity ‐ reported as median (IQR) Swollen joint count (assumed 66) ‐ 0 = no swollen joints; 66 = 66 swollen joints ‐ reported as median (IQR) Tender joint count (assumed 68) ‐ 0 = no tender joints; 68 = 68 tender joints ‐ reported as median (IQR)
Notes	Clinical trials registration: not reported Funding: not reported Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"At enrolment, patients were randomly divided into two groups…" No further detail is provided to describe the randomisation process
Allocation concealment (selection bias)	High risk	Allocation concealment was not reported in the article
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants or personnel was not attempted
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding of outcome assessors was not attempted
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	There was no discussion regarding handling of incomplete outcome data
Selective reporting (reporting bias)	Unclear risk	This could not be substantiated, as no trial registry record was available for comparison
Other bias	Unclear risk	Marked differences in baseline characteristics were evident; use of steroids was not forbidden, and their use was not reported Compliance was not discussed Overall this trial was judged to have unclear risk of bias for outcomes