Systematic review and meta-analysis of prophylactic abdominal drainage after pancreatic resection

Table 4 Quality of assessment of included studies

Cohort studies	Representativeness of the exposed cohort	Selection of the non-exposed cohort	Ascertainment of exposure	Comparability between the two cohorts	Assessment of outcome	Length of follow-up
Heslin et al[6]	Potential selection bias	Same patient base	Surgical record	No restriction/matching	Independent assessment	NM
Paulus et al[26]	Representative	Same patient base	Surgical record	No restriction/matching	Surgical record	NM
Fisher et al[7]	Representative	Different patient base	Surgical record	No restriction/matching	Surgical record	30 d
Adham et al[29]	Representative	Same patient base	Surgical record	No restriction/matching	Surgical record	90 d
Correa-Gallego et al[9]	Representative	Same patient base	Surgical record	No restriction/matching	Surgical record	90 d
Metha et al[28]	Representative	Same patient base	Surgical record	No restriction/matching	Surgical record	90 d
Case-control study	Representativeness of the cases	Selection of Controls	Ascertainment of exposure	Comparability of cases and controls	Assessment of outcome	Definition of Controls and cases
Lim et al[27]	Potential selection bias	Hospital control	Surgical record	One to one matching	Surgical record	Surgical record
RCTs	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting
Conlon et al[8]	Low risk	Low risk	High risk	Low risk	Unclear risk	Low risk
Van Buren et al[10]	Low risk	Low risk	High risk	Unclear risk	Low risk	Low risk

RCT: Randomized controlled trial.