Study	Reason for exclusion
Bruni 1965	RCT. Included women with "postpartum pain", not exclusively women with perineal pain; results not reported separately for women with perineal pain
Gindhart 1971	RCT. Did not assess aspirin for perineal pain, and rather assessed 2 agents: 1 (Darvon), containing propoxyphene with aspirin, phenacetin, and caffeine; and 1 (Fiorinal) which combined aspirin, phenacetin, and caffeine with a mild sedative, butalbital
Gruber 1979	RCT. Included women with "postpartum pain", not exclusively women with perineal pain; results not reported separately for women with perineal pain
Moggian 1972	RCT. Included women with "postpartum pain", not exclusively women with perineal pain; results not reported separately for women with perineal pain
Prockop 1960	RCT. Did not assess aspirin for perineal pain, and rather assessed an aspirin compound (acetophenetidin acetylsalicylic acid and caffeine); codeine and an aspirin compound; dextropropoxyphene; dextropropoxyphene and an aspirin compound; and a starch placebo
Rubin 1984	RCT. Did not assess aspirin for perineal pain, and rather assessed an aspirin/caffeine combination; an acetaminophen/aspirin combination; acetaminophen alone; and placebo
Santiago 1959	Not RCT: "In consecutive cases of vaginal delivery with episiotomy, orders in alternating patients for analgesic 1 or analgesic 2... were written". This study assessed Darvon Compound (dextro propoxyphene and acetylsalicylic acid compound); and a preparation containing acetylsalicylic acid, acetophenetidin, caffeine and codeine phosphate. Aspirin not assessed
Sunshine 1983c	RCT. Included women with "postpartum pain", not exclusively women with perineal pain; results not reported separately for women with perineal pain
Sunshine 1985	RCT. Included women with "postpartum pain", not exclusively women with perineal pain; results not reported separately for women with perineal pain
Van der Pas 1984	Did not assess single dose aspirin, and rather assessed twice daily acetylsalicylic acid; and naproxen; it was not clear whether this was a randomised controlled trial

RCT: randomised controlled trial