Characteristics of studies.

CCS = case-control study, CS = case series, FEV1 = forced expiratory volume in the first second, DLCO = diffusing capacity of the lung for carbon monoxide, FEV1% = FEV1 as a percent predicted DLCO% = DLCO as a percent predicted, ppoFEV1% = predicted postoperative FEV1 expressed as a percent predicted, ppoDLCO% = predicted postoperative DLCO expressed as a percent predicted. Characteristics of studies.