Summary of findings 2. Rilonacept versus placebo for reducing inflammation in familial Mediterranean fever.

Rilonacept versus placebo for reducing inflammation in familial Mediterranean fever
Participant or population: people with familial Mediterranean fever Settings: outpatient (USA) Intervention: rilonacept Comparison: placebo
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Placebo	Rilonacept
Number of participants experiencing an attack1 Follow‐up: 3 months	1000 per 1000	870 per 1000 (590 to 1000)	RR 0.87 (0.59 to 1.26)	14 (1 study)	⊕⊕⊕⊝ moderate2	RR < 1 indicates an advantage to rilonacept, no significant difference.
Duration of attacks1 Follow‐up: 12 months	The median duration was 3.2 days.	The median duration was 2.8 days.	NA	14 (1 study)	⊕⊕⊝⊝ low2,3	First‐arm data were not reported separately.
Number of days between attacks1 Follow‐up: 12 months	The median time was 15 days to the first attack and 36 days to the second attack.	The median time was20 days to the first attack and 90 days to the second attack.	NA	14 (1 study)	⊕⊕⊝⊝ low2,3	First‐arm data were not reported separately.
Prevention of AA amyloidosis	Not reported.			NA
Adverse drug reactions	1 participant reported gastrointestinal symptoms in the placebo group.	3 participants reported gastrointestinal symptoms in the rilonacept group.	NA	14 (1 study)	⊕⊕⊝⊝ low2,3	First‐arm data were not reported separately, the reported data was at the end of the study.
	No participant reported hypertension in the placebo group.	1 participant reported hypertension in the rilonacept group.	NA
	1 participant reported headache in the placebo group.	1 participant reportedheadache in the rilonacept group.	NA
	7 participants reported respiratory tract infections in the placebo group as follows: respiratory infection (n = 1), upper respiratory tract infection or otitis (n = 4), sinusitis (n = 1) and other respiratory infection (n = 1).	4 participants reported respiratory tract infections in the rilonacept group as follows: pneumonia (n = 1), upper respiratory tract infection or otitis (n = 1), sinusitis (n = 1), other respiratory infection (n = 1).	NA
	5 participants reported injection site reactions in the placebo group.	7 participants reportedinjection site reactions in the rilonacept group.	NA
	2 participants reported herpes in the placebo group.	1 participant reported herpes in the rilonacept group.	NA
Acute phase response	The median ESR was 14 mm/h in the placebo group.	The median ESR was 5.8 mm/h in the rilonacept group.	NA	14 (1 study)	⊕⊕⊝⊝ low2,3	First‐arm data were not reported separately, the reported data was at the end of the study.
	The median fibrinogen was 9.56 μmol/L in the placebo group.	The median fibrinogen was 6.56 μmol/L in the rilonacept group.	NA
	The median CRP was4 mg/L in the placebo group.	The median CRP was2 mg/L in the rilonacept group.	NA
	The median SAA concentration was 15 mg/L in the placebo group.	The median SAA concentration was 13 mg/L in the rilonacept group.	NA
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). AA: amyloid A; CI: confidence interval; CRP: C‐reactive protein; ESR: erythrocyte sedimentation rate; RR: risk ratio; SAA: serum amyloid A protein.
GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate.

1. Attack definition: episodes of fever, serositis, acute arthritis, or an erysipelas‐like rash.
2. Downgraded once for the small sample size.
3. Downgraded once for unavailable outcome data from each separate phase.