Table 1—

Bilevel noninvasive positive pressure ventilation in chronic obstructive pulmonary disease: study characteristics

First author [Ref.]Study designLengthEnrolledRandomisedCompletedConcealed randomisation
RCTs
 Diaz 19BS, BA3 weeks563636Yes
 Gay 21BS, BA3 months351310Yes
 Renston 22BS, BA<1 week171717Yes
 Casanova 11BS, RM1 yr805244Yes
 Clini 23BS, RM2 yrs1228647No
 Garrod 24BS, RM8 weeks454537Yes
Non-RCTs
 Ambrosino 25CSVR, WS, RM<1 week777
 Highcock 18CSVR, WS, RM<1 week888
 Krachman 20CSVR, WS, BA<1 week666
 Lien 26CSVR, WS, RM<1 week111111
 Lin 27CSVR, WS, RM6 weeks171210
 Marangoni 28CSVR, WS, RM<1 week141414
 Meecham Jones 29CSVR, WS, BA3 months181814
 Nava 17CSVR, WS, RM<1 week776
 Strumpf 30CSVR, WS, RM6 months23197
  • Data are presented as n. All randomised controlled trials (RCTs) were single blind. All non-RCTs included random order assignment and statistical control of confounders. BS: between subjects; BA: before/after; RM: repeated measures; CSVR: crossover; WS: within subjects.