Table 1 Study protocols

Antunes (2016) [45]

Mini Wright® (Clement Clarke International Ltd. Edinburgh Way Harlow, Essex, UK) peak flow meter portable device with a disposable mouthpiece

Random position order

1 min

Moderate

Badr (2002) [46]

Pressure manometer, vitalograph (Compact, Vitalograph Ltd., Buckingham, UK)

Random position order

Random test order (PEF and PEmax) Subjects instructed on equipment use, practiced before test

5 min

Low

Baydur (2001) [35]

Spirometry

Random position order

N/A

Moderate

Ben-Dov (2009) [17]

Spirometry

N/A

N/A

Moderate

Benedik (2009) [52]

Helium dilution

First position always sitting

5 min

Moderate

Ceridon (2011) [18]

Spirometry, DLCO measured by rebreathe technique

N/A

30 min supine position prior to test Time prior to seated measurement not mentioned

Moderate

Chang (2005) [53]

Spirometry, FRC measured using helium dilution

First position always supine

5 min

Moderate

Costa (2015) [54]

Mouth pressure meter

Random position order

10 min

Moderate

De (2012) [29]

Spirometry

First position was always sitting

N/A

Moderate

Elkins (2005) [47]

Pressure manometer, spirometry - mass flow sensor

Random position and test order (PEF, PEmax)

Subjects instructed on equipment use, practiced before test

5 min

Low

Faggiano (1998) [58]

Single breath technique using a Medical Graphics PF/DX module (Medical Graphics St. Paul, Minn, USA) for determining DLCO

Random position order

10 min

Moderate

Ganapathi (2015) [19]

Digital spirometry (BIOPAC System Inc. Goleta, California, USA)

N/A

N/A

Moderate

Gianinis (2013) [48]

Portable peak expiratory flow-device

Random position order

N/A

Moderate

Kim (2012) [36]

Spirometry

N/A

N/A

Moderate

Linn (2000) [33]

Spirometry

Random position order

N/A

Moderate

Manning (1999) [20]

Spirometry, single breath for determining DLCO

Two protocols (Session A & B). First chosen at random then alternated for successive subjects.

First position always sitting.

15 min

Moderate

McCoy (2010) [49]

Peak flow meter

Random position order.

Subjects instructed on equipment use, practiced before test

N/A

Moderate

Melam (2014) [30]

Spirometry (Excel/PC-based pulmonary function tests)

Random position order

N/A

Moderate

Meysman (1998) [3]

Spirometry, peak flow meter

Random position order

10 min

Moderate

Miccinilli (2016) [40]

Spirometry

N/A

N/A

Moderate

Mohammed (2017) [31]

Spirometry

Order of positions always standing, sitting, supine, lateral decubitus

N/A

Moderate

Myint (2017) [42]

Spirometry

Order of positions was standing, sitting, supine

N/A

Moderate

Naitoh (2014) [39]

Spirometry, breath dynamometer (Chest Co. Ltd)

First position always sitting

N/A

Moderate

Ogiwara (2002) [55]

Vitalpower KH-101 (Chest M.I. Inc., Japan)

Random position order

10 min

Moderate

Ottaviano (2016) [50]

Peak flow meter

Random position order

N/A

Moderate

Palermo (2005) [21]

Spirometry, DLCO measured by a single breath technique

Random position order

15 min

Moderate

Park (2010) [34]

Spirometry

N/A

N/A

Moderate

Patel (2015) [22]

Spirometry

First position always sitting

N/A

Moderate

Peces-Barba (2004) [56]

Single breath technique, rebreathing technique for determining DLCO

N/A

3–5 min

Moderate

Poussel (2014) [38]

Spirometry

Random position order

N/A

Moderate

Razi (2007) [32]

Spirometry

Alternately sitting, standing

N/A 15 min between positions

Moderate

Roychowdhury (2011) [44]

Spirometry

N/A

N/A

5 min rest between positions

Moderate

Saxena (2006) [23]

Spirometry

N/A

N/A

Moderate

Sebbane (2015) [41]

Spirometry, multiple breath helium dilution method

First position always sitting

N/A

Moderate

Stewart (2000) [24]

Single breath method for determining DLCO

N/A, 72 h between positions

15 min

Moderate

Terson de Paleville (2014) [37]

Spirometry, MP45–36-350 differential pressure transducer Validyne Engineering, (Northridge Ca, USA)

First position always sitting

30 min

Moderate

Terzano (2009) [57]

Single breath DLCO technique

Random position order

At least 15 min

Moderate

Tsubaki (2009) [28]

Micro RPM 01 (Micro Medical, UK), spirometry

Random position order

N/A

Moderate

Varrato (2001) [25]

Spirometry

N/A

N/A

Moderate

Vilke (2000) [26]

Spirometry

First position always supine/prone

N/A

Moderate

Wallace (2013) [51]

Peak flow meter

Random position order

N/A

Moderate

Watson (2005) [43]

Multi-breath helium dilution,

spirometry

N/A

N/A

Moderate

Yap (2000) [27]

Spirometry, FRC was measured using helium dilution

First position always sitting

5 min

Moderate