Table 1.

Characteristics of the studies that were included: flap vs laying open technique

	Study	No. of patients	Lost to follow up	Type of flap	Ratio flap: other	Inclusion criteria	Exclusion criteria	Primary endpoint	Secondary endpoints	Type of randomisation	Blinding	Follow up
Comparison flap vs laying open technique	Keshvari et al35	321	0	Karidakis flap	161:160	PSD		Pain, time to complete wound healing, time to return to work, patient satisfaction, recurrence rate, complications		Computer generated	Patient	Median 49 months
	Käser et al34	102	5	Limberg flap	51:51	PSD	Acute abscess, recurrent PSD, age < 18 years, lack of consent, immunodeficiency, pregnancy, dermatological disease	Time to return to work	Pain, complications, recurrence rate, patient satisfaction	Computer generated	No	12 months
	Fazeli et al36 2006	144	6	Z‐plasty	72:72		Acute abscess	Pain, duration of hospital stay, time to return to work, complications, time to complete wound healing, recurrence rate			No	Mean 22 months
	Jamal et al33	49	4	Limberg flap	24:25	PSD	Lost to follow up	Pain, duration of hospital stay, complications, recurrence rate				Mean 18 months
	Rashidian et al37	60	0	Limberg flap	20:40	Primary PSD	Acute abscess, recurrent PSD	Duration of hospital stay, time to return to work, time to complete wound healing, recurrence rate, complications		Block randomisation		Mean 18 months

Abbreviations: DC, direct closure; PSD, pilonidal sinus disease.