Gender Differences in the Diagnostic Accuracy of SPECT Myocardial Perfusion Imaging: A Bivariate Meta-analysis
Aline Iskandar, MD, Brendan Limone, PharmD, Matthew W. Parker, MD, Andrew Perugini, PharmD, Hyejin Kim, PharmD, Charles Jones, PharmD, Brian
Calamari PharmD, Craig I. Coleman, PharmD, Gary V. Heller, MD, PhD
Supplemental Materials
SUPPLEMENTAL METHODS
QUADAS Items and Guidelines for Scoring
- Was the spectrum of patients representative of the patients who will receive in the test in practice? (Patient spectrum).
To be scored “yes”, the prevalence of coronary artery disease could not be higher than 70%.
- Were selection criteria clearly described? (Selection criteria)
To be scored “yes”, the article had to at least report inclusion and exclusion criteria.
- Is the reference standard likely to correctly classify the target condition? (Reference standard)
To be scored “yes”, investigators had to perform quantitative coronary angiography using a threshold of 50% stenosis.
- Is the period between reference standard and index test short enough to be reasonably sure that the target condition did not change between the two tests? (Disease progression bias)
To be scored “yes”, stress myocardial perfusion imaging and coronary angiography had to be performed within 30 days.
- Did the whole sample or a random selection of the sample receive verification using the reference standard? (Partial verification bias)
To be scored “yes”, subjects had to undergo coronary angiography regardless of stress myocardial perfusion images findings.
- Did patients receive the same reference standard regardless of the index test result? ( Differential verification)
All studies were scores “yes” based on the inclusion criteria.
- Was the reference standard independent of the index test (i.e., the index test did not form part of the reference standard)? (Incorporation bias)
All studies were scores “yes” based on the inclusion criteria.
- Was the execution of the index test described in sufficient detail to permit replications of the test? ( Test details)
To be scored “yes”, the study had to specify type of stress used, radiotracer used, and data acquisition and reconstruction settings.
- Was the execution of the reference standard described in sufficient detail to permit its replication? (Reference standard details)
To be scored “yes”, the study had to state whether conventional coronary angiography or quantitative angiography was performed, and if conventional angiography, state method for evaluating stenosis (i.e., “worst view” or “average of multiple views”) or if quantitative angiography, describe or cite the quantitative technique used.
- Were the index test results interpreted without knowledge of the result of the reference standard? (Test review bias)
To be scored “yes”, the investigators had to clearly state that stress myocardial perfusion images were interpreted without knowledge of the results of the coronary angiograms.
- Were the reference standard results interpreted without knowledge of the results of the reference standard? (Diagnostic review bias)
To be scored “yes”, the investigators had to clearly state that coronary angiograms were interpreted without results of the stress myocardial perfusion imaging.
- Were the same clinical data available when test results were interpreted as would be available when the test is used in practice? (Clinical data)
To be scored “yes”, the investigators had to provide clinical data when stress myocardial perfusion images were being interpreted.
- Were uninterpretable or intermediate test results reported? (Uninterpretable results)
To be scored “yes”, study investigators had to report any uninterpretable results or state that there were no uninterpretable results.
- Were withdrawals from the study explained? (Withdrawals)
To be scored “yes”, the study investigators had to clearly show the disposition of all patients who entered the study, preferably by reporting a flow diagram of all study participants or at least by reporting the number and disposition of withdrawals.
Supplemental Table 1 Characteristics of Included Studies in WomenFirst Author, Year (Reference) / Location / Setting / Total patients (n) / Mean age (y) / +/- SD
(y) / Stent patients
(n) / CABG patients
(n) / Angioplasty patients(n)
Amanullah, 1996 (10) / Los Angeles, CA, USA / University Hospital / 130 / 72 / 10 / 0 / 0 / 0
Bokhari,
2008 (11) / New York, NY, USA / University Hospital / 68 / 62 / 13 / 0 / 0 / 0
Elhendy,
1998 (13) / Rotterdam,
The Netherlands / University Hospital / 70 / 58 / 14 / NR / NR / NR
Elhendy,
2006 (12) / Rotterdam,
The Netherlands / University Hospital / 88 / 58 / 11 / NR / NR / NR
Ho,
1998 (14) / Taipei, Taiwan / University Hospital / 44 / 62 / 11 / NR / NR / NR
Lu,
2010 (15) / Italy / University Hospital / 76 / 61 / 7 / 0 / 0 / 0
Mieres,
2007 (16) / Manhasset, NY, USA / University Hospital / 42 / 67 / 9 / 0 / 0 / 0
Mohiuddin,
1996 (17) / Omaha, NE, USA;
Charleston, WV, USA / University Hospital / 83 / 60 / 8 / 0 / 11 / 13
Rollan,
2002 (18) / Vallaolid, Spain;
Madrid, Spain;
Las Palms, Spain / University Hospital / 54 / 65 / 9 / 0 / 0 / 0
Santana-Boado, 1998 (19) / Barcelona, Spain / University Hospital / 63 / 60 / 10 / NR / NR / NR
Slavich,
1996 (20) / Udine, Italy; Rotterdam, The Netherlands;
North Carolina, USA / University Hospital / 46 / 59 / 11 / 0 / 0 / 0
Smanio,
2007 (21) / Sao Paolo, Brazil / University Hospital / 104 / NR / NR / 0 / 0 / 0
Taillefer,
1997 (23) / Montreal, Canada / University Hospital / 85 / NR / NR / 0 / 0 / 0
Taillefer,
1999 (22) / Montreal, Canada / University Hospital / 53 / 60 / 12 / 0 / 0 / 0
Takeuchi,
1996 (24) / Kitakyushu, Japan / University Hospital / 61 / 65 / NR / 0 / 4 / 3
Van Train,
1994 (25) / Los Angeles, CA, USA;
Kansas City, MO, USA;
Indianapolis, IN, USA;
Atlanta, GA, USA; New York, NY, USA;
Detroit, MI, USA; Orlando, FL, USA / University Hospital / 30 / 56 / NR / 0 / 0 / 0
Yeih,
2007 (26) / Taipei, Taiwan / University Hospital / 51 / 63 / 9 / 0 / 0 / 0
Abbreviations: n=number of patients; NR=not reported; y=year(s); SD = standard deviation.
SupplementalTable 2 Camera Details of Included Studies in WomenFirst Author, Year (Reference) / Camera Manufacturer / Camera Details / Nuclear Readers / Reading Model / Diagnostic Standard / Consecutive Patients / Funding source(s)
Amanullah, 1996 (10) / Not Specified / SPECT / 2 / 20-Segment / Conventional Angiography / Yes / Non-Commercial Grants
Bokhari,
2008 (11) / Not Specified / Gated SPECT / NR / Not Specified / Conventional Angiography / Unclear / None Declared
Elhendy,
1998 (13) / Not Specified / SPECT / 1 / 47-Segment / Quantitative Angiography / Unclear / Non-Commercial Grants
Elhendy,
2006 (12) / Picker / SPECT / 1 / 47-Segment / Quantitative Angiography / Unclear / Commercially Sponsored Study
Ho,
1998 (14) / GE / SPECT / 2 / 10-Segment / Quantitative Angiography / Yes / None Declared
Lu,
2010 (15) / Not Specified / SPECT / NR / 6-Segment / Conventional Angiography / Unclear / None Declared
Mieres,
2007 (16) / Not Specified / Gated
SPECT / 3 / Not Specified / Conventional Angiography / Yes / Commercial Grant
Mohiuddin,
1996 (17) / Not Specified / SPECT / 1 / 6-Segment / Conventional Angiography / Yes / None Declared
Rollan,
2002 (18) / Siemens / SPECT / NR / Not Specified / Conventional Angiography / Yes / None Declared
Santana-Boado, 1998 (19) / Elscint / SPECT / 3 / 13-Segment / Conventional Angiography / Yes / Non-Commercial Grants
Slavich,
1996 (20) / Siemens / SPECT / 2 / Not Specified / Conventional Angiography / Yes / None Declared
Smanio,
2007 (21) / Not Specified / gated SPECT / 2 / 17-Segment / Quantitative Angiography / Unclear / None Declared
Taillefer,
1997 (23) / Sopha Medical / Gated
SPECT / 3 / 17-Segment / Conventional Angiography / Yes / Commercial Grants
Taillefer,
1999 (22) / Sopha Medical / gated SPECT / 3 / 17-Segment / Conventional Angiography / Yes / Commercial Grants
Takeuchi,
1996 (24) / Shimadzu Precision Instruments / SPECT / 2 / Not Specified / Quantitative Angiography / Yes / None Declared
Van Train,
1994 (25) / Siemens;
GE / SPECT / 2 / Not Specified / Conventional Angiography / Yes / Non-Commercial Grants
Yeih,
2007 (26) / GE / SPECT / 2 / 10-Segment / Quantitative Angiography / Unclear / None Declared
Abbreviations: GE = General Electric; NR = Not Reported; SPECT = Single Photon Emission Computed Tomography.
SupplementalTable 3SPECT Test Details of the Included Studies in WomenFirst Author, Year (Reference) / Clinical presentation / Stress / Pharmacologic stress agent / Radio-tracer / Dose
Amanullah,
1996 (10) / Suspected CAD / Pharmacologic / Adenosine / Thallium-201, Tc99m-Sestamibi / 2.5-3.5 mCi Th-201
20-30 mCi Tc99m
Bokhari,
2008 (11) / Suspected CAD / Exercise / None / Thallium-201, Tc99m-Sestamibi / 3-3.3 mCi Tl-201
25-30 mCi Tc99m
Elhendy,
1998 (13) / Suspected CAD / Pharmacologic / Dobutamine / Tc99m-Sestamibi / 10 mCI rest/stress
Elhendy,
2006 (12) / Suspected CAD / Exercise or Pharmacologic / Dobutamine / Tc99m-Tetrofosmin / 10 mCi rest/stress
Ho,
1998 (14) / Known or suspected CAD / Pharmacologic / Dipyridamole, Dobutamine / Thallium-201 / 2 – 2.5 mCi
Lu,
2010 (15) / Suspected CAD / Exercise / None / Tc99m-Sestamibi / 25 mCi stress/rest
Mieres,
2007 (16) / Suspected CAD / Exercise or Pharmacologic / Adenosine / Tc99m-Sestamibi,
Thallium-201 / NR
Mohiuddin,
1996 (17) / Known or suspected CAD / Pharmacologic / Adenosine / Thallium-201 / 3.5 mCi
Rollan,
2002 (18) / Suspected CAD / Pharmacologic / Dobutamine / Tc99m-Sestamibi / 20 mCi rest/stress
Santana-Boado, 1998 (19) / Known or suspected CAD / Exercise or Pharmacologic / Dipyridamole / Tc99m-Sestamibi / 15 mCi rest/stress
Slavich,
1996 (20) / Suspected CAD / Pharmacologic / Dobutamine / Tc99m-Sestamibi / 20 mCi rest/stress
Smanio,
2007 (21) / Asymptomatic diabetics / Pharmacologic / Dipyridamole / Tc99m-Sestamibi / 20 mCi rest/stress
Taillefer,
1997 (23) / Known or suspected CAD / Exercise or Pharmacologic / Dipyridamole / Tc99m-Sestamibi / 25-30 mCi rest/stress
Taillefer,
1999 (22) / Known or suspected CAD / Exercise or Pharmacologic / Dipyridamole / Tc99m-Sestamibi / 25-30 mCi rest/stress
Takeuchi,
1996 (24) / Suspected CAD / Exercise or Pharmacologic / Dipyridamole / Thallium-201 / 2 mCi
Van Train,
1994 (25) / NR / Exercise / None / Tc99m-Sestamibi / 8 mCi rest
22 mCi stress
Yeih,
2007 (26) / Suspected CAD / Pharmacologic / Dobutamine / Thallium-201 / 2-3 mCi rest/stress
Abbreviations: CAD = Coronary Artery Disease; mCi = millicurie; MI = Myocardial Infarction; NR = Not Reported; Tc99m = Technetium-99m.
Supplemental Table 4 Characteristics of Included SPECT Studies in MenFirst Author, Year (Reference) / Location / Setting / Total patients (n) / Mean age (y) / +/- SD
(y) / Stent patients
(n) / CABG patients
(n) / Angioplasty patients
(n)
Acampa,
1998 (27) / Naples, Italy / University Hospital / 26 / 50 / 9 / NR / NR / NR
Bokhari,
2008 (11) / New York, NY, USA / University Hospital / 150 / 62 / 13 / 0 / 0 / 0
Cuocolo,
1997 (28) / Napoli,
Italy / University Hospital / 24 / 51 / 6 / 0 / 0 / 0
Karlsson,
1995 (29) / Sweden / University Hospital / 170 / 59 / NR / 0 / 0 / 0
Kiat,
1990 (31) / Los Angeles, CA, USA;
Dallas, TX, USA / University Hospital / 39 / NR / NR / NR / NR / NR
Kiat,
1992 (30) / Los Angeles, CA, USA / University Hospital / 35 / NR / NR / 0 / 0 / 0
Maddahi,
1989 (32) / Los Angeles, CA, USA; / University Hospital / 110 / NR / NR / 0 / 0 / 0
Mohiuddin,
1996 (17) / Omaha, NE, USA;
Charleston, WV, USA / University Hospital / 119 / 58 / 10 / 0 / 15 / 21
Rosenkranz,
2001 (33) / Koln, Germany / University Hospital / 34 / 52 / 12 / 34 / NR / 34
Santana-Boado, 1998 (19) / Barcelona, Spain / University Hospital / 100 / 58 / 8 / NR / NR / NR
Sciammarella,
1992 (34) / Milano, Italy / Community Hospital / 45 / 62 / 17 / NR / NR / NR
Van Train,
1994 (25) / Los Angeles, CA, USA;
Kansas City, MO, USA;
Indianapolis, IN, USA;
Atlanta, GA, USA; New York, NY, USA;
Detroit, MI, USA; Orlando, FL, USA / University Hospital / 94 / 56 / NR / 0 / 0 / 0
Zafar-ul-Islam,
2009 (35) / Multan,
Parkistan / Military Hospital / 196 / NR* / NR / 0 / 0 / 0
*Age range 30-45 years. Abbreviations: n=number of patients; NR=not reported; SD = standard deviation; y=year(s).
SupplementalTable 5 Camera Details of Included in Men.First Author, Year (Reference) / Camera Manufacturer / Camera Details / Nuclear Readers / Reading Model / Diagnostic Standard / Consecutive Patients / Funding source(s)
Acampa,
1998 (27) / Elscint / SPECT / 2 / 22-Segment / Conventional Angiography / Unclear / None Declared
Bokhari,
2008 (11) / Not Specified / gated SPECT / NR / Not Specified / Conventional Angiography / Unclear / None Declared
Cuocolo,
1997 (28) / Elscint / SPECT / 2 / 22-Segment / Conventional Angiography / Yes / None Declared
Karlsson,
1995 (29) / Siemens;
Picker / AC SPECT, Non-AC SPECT / 2 / 9-Segment / Conventional Angiography / Unclear / Non-Commercial Grants
Kiat,
1990 (31) / Siemens;
Johnson and Johnson / SPECT / NR / 13-Segment / Conventional Angiography / Unclear / Non-Commercial Grants
Kiat,
1992 (30) / Siemens / SPECT / 1 / 20-Segment / Quantitative Angiography / Yes / Non-Commercial Grants
Maddahi,
1989 (32) / GE / SPECT / NR / 102-Segment / Conventional Angiography / Yes / Non-Commercial Grants
Mohiuddin,
1996 (17) / Not Specified / SPECT / 1 / 6-Segment / Conventional Angiography / Yes / None Declared
Rosenkranz,
2001 (33) / Picker / SPECT / 2 / 28-Segment / Conventional Angiography / Yes / None Declared
Santana-Boado, 1998 (19) / Elscint / SPECT / 3 / 13-Segment / Conventional Angiography / Yes / Non-Commercial Grants
Sciammarella,
1992 (34) / Not Specified / SPECT / 3 / 20-Segment / Quantitative Angiography / Unclear / None Declared
Van Train,
1994 (25) / Siemens;
GE / SPECT / 2 / Not Specified / Conventional Angiography / Yes / Non-Commercial Grants
Zafar-ul-Islam, 2009 (35) / NR / SPECT / NR / Not Specified / Conventional Angiography / Unclear / None Declared.
Abbreviations: AC = Attenuation Correction GE = General Electric; NR = Not Reported; SPECT = Single Photon Emission Computed Tomography.
SupplementalTable 6SPECT Test Details of the Included Studies in Men.First Author, Year (Reference) / Clinical presentation / Stress / Pharmacologic stress agent / Radio-tracer / Dose
Acampa,
1998 (27) / Suspected or known CAD / Exercise / None / Tc99m-Tetrofosmin / 30 mCi rest
10 mCi stress
Bokhari,
2008 (11) / Suspected CAD / Exercise / None / Thallium-201, Tc99m-Sestamibi / 3-3.3 mCi Tl-201
25-30 mCi Tc99m
Cuocolo,
1997 (28) / Suspected CAD / Pharmacologic / Adenosine / Tc99m-Tetrofosmin / 20 mCi
Karlsson,
1995 (29) / Known CAD / Exercise / None / Thallium-201 / 2.1 mCi
Kiat,
1990 (31) / NR / Exercise / None / Tc99m-Sestamibi / 30 mCi
Kiat,
1992 (30) / NR / Exercise / None / Thallium-201 / 3-4 mCi
Maddahi,
1989 (32) / Suspected or Known CAD / Exercise / None / Thallium-201 / 3-4 mCi
Mohiuddin,
1996 (17) / Suspected or Known CAD / Pharmacologic / Adenosine / Thallium-201 / 3.5 mCi
Rosenkranz,
2001 (33) / Known CAD / Pharmacologic / Dobutamine / Thallium-201, Tc99m-Sestamibi / 2 mCi Tl-201
20 mCi Tc99m
Santana-Boado, 1998 (19) / Suspected or Known CAD / Exercise or Pharmacologic / Dipyridamole / Tc99m-Sestamibi / 15 mCi rest/stress
Sciammarella,
1992 (34) / Suspected CAD / Exercise / None / Tc99m-Sestamibi / 17.7 mCi rest
23.0 mCi stress
Van Train,
1994 (25) / NR / Exercise / None / Tc99m-Sestamibi / 8 mCi rest
22 mCi stress
Zafar-ul-Islam,
2007 (35) / Suspected CAD / NR / NR / Thallium-201 / NR
Abbreviations: CAD = Coronary Artery Disease; mCi = millicurie; MI = Myocardial Infarction; NR = Not Reported; Tc99m = Technetium-99m.
Supplemental Table 7Reviewer Judgments about Methodological Quality of the Included Studies in Women Using QUADAS Items (1)First Author, Year (Reference) / Patient Spectrum / Selection Criteria / Reference Standard / Disease Progression Bias / Partial Verification Bias / Differential Verification / Incorporation Bias
Amanullah, 1996 (10) / No / Yes / Yes / No / Yes / Yes / Yes
Bokhari,
2008 (11) / Yes / Yes / Yes / No / Yes / Yes / Yes
Elhendy,
1998 (13) / Yes / Yes / Yes / No / Yes / Yes / Yes
Elhendy,
2006 (12) / Yes / Yes / Yes / No / Yes / Yes / Yes
Ho,
1998 (14) / Yes / Yes / Yes / Yes / Yes / Yes / Yes
Lu,
2010 (15) / Yes / Yes / Yes / No / Yes / Yes / Yes
Mieres,
2007 (16) / Yes / Yes / Yes / Yes / Yes / Yes / Yes
Mohiuddin,
1996 (17) / No / Yes / Yes / No / Yes / Yes / Yes
Rollan,
2002 (18) / Yes / Yes / Yes / Indeterminate / Yes / Yes / Yes
Santana-Boado, 1998 (19) / Yes / Yes / Yes / No / Yes / Yes / Yes
Slavich,
1996 (20) / Yes / Yes / Yes / No / Yes / Yes / Yes
Smanio,
2007 (21) / Yes / Yes / Yes / No / Yes / Yes / Yes
Taillefer,
1997 (23) / No / Yes / Yes / No / Yes / Yes / Yes
Taillefer,
1999 (22) / No / Yes / Yes / No / Yes / Yes / No
Takeuchi,
1996 (24) / Yes / Yes / Yes / Indeterminate / Yes / Yes / Yes
Van Train,
1994 (25) / No / No / Yes / Indeterminate / Yes / Yes / Yes
Yeih,
2007 (26) / Yes / Yes / Yes / Yes / Yes / Yes / Yes
“Yes” scores indicate that a study clearly reported measures taken to reduce the indicated source of bias. See QUADAS Tool in Appendix 1.
Supplemental Table 8Reviewer Judgments about Methodological Quality of the Included Studies in Women Using QUADAS Items (2)First Author, Year (Reference) / Test Details / Reference Standard Details / Test Review Bias / Diagnostic Review Bias / Clinical Data / Uninterpretable Results / Withdrawals
Amanullah, 1996 (10) / Yes / Yes / Indeterminate / Yes / Indeterminate / No / Yes
Bokhari,
2008 (11) / No / Yes / Yes / Indeterminate / No / No / Yes
Elhendy,
1998 (13) / Yes / Yes / Yes / Indeterminate / No / No / Yes
Elhendy,
2006 (12) / Yes / Yes / Indeterminate / Indeterminate / No / No / Yes
Ho,
1998 (14) / Yes / Yes / Yes / Indeterminate / Indeterminate / No / No
Lu,
2010 (15) / Yes / Yes / Indeterminate / Yes / Indeterminate / Yes / No
Mieres,
2007 (16) / No / Yes / Indeterminate / Yes / No / No / Yes
Mohiuddin,
1996 (17) / Yes / Yes / Yes / Yes / No / Yes / Yes
Rollan,
2002 (18) / No / Yes / Indeterminate / Indeterminate / Indeterminate / No / No
Santana-Boado, 1998 (19) / Yes / Yes / Yes / Yes / Indeterminate / No / Yes
Slavich,
1996 (20) / No / Yes / Yes / Indeterminate / Indeterminate / No / Yes
Smanio,
2007 (21) / Yes / Yes / Yes / Yes / Indeterminate / Yes / Yes
Taillefer,
1997 (23) / Yes / Yes / Yes / Yes / No / No / Yes
Taillefer,
1999 (22) / Yes / Yes / Yes / Yes / No / No / No
Takeuchi,
1996 (24) / Yes / Yes / Indeterminate / Yes / No / No / No
Van Train,
1994 (25) / No / No / Yes / Indeterminate / No / No / No
Yeih,
2007 (26) / Yes / Yes / Yes / Indeterminate / Indeterminate / No / Yes
“Yes” scores indicate that a study clearly reported measures taken to reduce the indicated source of bias. See QUADAS Tool in Appendix 1.
Supplemental Table 9Reviewer Judgments about Methodological Quality of the Included Studies of Men Using QUADAS Items (1)First Author, Year (Reference) / Patient Spectrum / Selection Criteria / Reference Standard / Disease Progression Bias / Partial Verification Bias / Differential Verification / Incorporation Bias
Acampa,
1998 (27) / No / Yes / Yes / Yes / Yes / Yes / Yes
Bokhari,
2008 (11) / Yes / Yes / Yes / No / Yes / Yes / Yes
Cuocolo,
1997 (28) / No / Yes / Yes / Yes / Yes / Yes / Yes
Karlsson,
1995 (29) / No / Yes / Yes / Yes / Yes / Yes / Yes
Kiat,
1990 (31) / No / No / Yes / No / Yes / Yes / Yes
Kiat,
1992 (30) / No / No / Yes / No / Yes / Yes / Yes
Maddahi,
1989 (32) / No / No / Yes / No / Yes / Yes / Yes
Mohiuddin,
1996 (17) / No / Yes / Yes / No / Yes / Yes / Yes
Rosenkranz,
2001 (33) / No / Yes / Yes / Indeterminate / Yes / Yes / No
Santana-Boado, 1998 (19) / No / Yes / Yes / No / Yes / Yes / Yes
Sciammarella,
1992 (34) / No / Yes / Yes / Yes / Yes / Yes / Yes
Van Train,
1994 (25) / No / No / Yes / Indeterminate / Yes / Yes / Yes
Zafar-ul-Islam
2009 (35) / Yes / Yes / Yes / Indeterminate / Yes / Yes / Yes
“Yes” scores indicate that a study clearly reported measures taken to reduce the indicated source of bias. See QUADAS Tool in Appendix 1.
Supplemental Table 10Reviewer Judgments about Methodological Quality of the Included Studies in Men Using QUADAS Items (2)First Author, Year (Reference) / Test Details / Reference Standard Details / Test Review Bias / Diagnostic Review Bias / Clinical Data / Uninterpretable Results / Withdrawals
Acampa,
1998 (27) / Yes / Yes / Yes / Indeterminate / No / Yes / Yes
Bokhari,
2008 (11) / No / Yes / Yes / Indeterminate / No / No / Yes
Cuocolo,
1997 (28) / Yes / Yes / Yes / Indeterminate / No / Yes / Yes
Karlsson,
1995 (29) / Yes / Yes / Indeterminate / Indeterminate / Indeterminate / No / No
Kiat,
1990 (31) / Yes / Yes / Indeterminate / Yes / Indeterminate / No / No
Kiat,
1992 (30) / Yes / Yes / Indeterminate / Yes / Indeterminate / No / Yes
Maddahi,
1989 (32) / Yes / Yes / Indeterminate / Yes / Indeterminate / No / Yes
Mohiuddin,
1996 (17) / Yes / Yes / Yes / Yes / No / Yes / Yes
Rosenkranz,
2001 (33) / Yes / Yes / Indeterminate / Indeterminate / Indeterminate / No / Yes
Santana-Boado, 1998 (19) / Yes / Yes / Yes / Yes / Indeterminate / No / Yes
Sciammarella,
1992 (34) / Yes / Yes / Yes / Indeterminate / No / No / No
Van Train,
1994 (25) / No / No / Yes / Indeterminate / No / No / No
Zafar-ul-Islam
2009 (35) / No / Yes / Indeterminate / Interminate / Indeterminate / No / Yes
“Yes” scores indicate that a study clearly reported measures taken to reduce the indicated source of bias. See QUADAS Tool in Appendix 1.