Table 2 A complete-case comparison is made between those studies published prior to 2007 and those published after 2008. Because of this time-window, 315 studies were excluded for this analysis. Differences in mean scores were calculated by unpaired T-tests; significance (p < 0.05) is indicated by an asteriks (*); significance after Bonferroni correction (36 significance tests: 32 signalling questions, 3 domains, 1 total score, hence 0.05/36, p ≤ 0.0014) is indicated by two asteriks (**). % complete denotes the completeness of reporting for that specific signalling question. Ranges per domain: 0–8 for domain 1, 0–15 for domain 2, and 0–9 for domain 3

DOMAIN I: RESEARCH TEAM AND REFLEXIVITY

1037

2.76

309

2.57

0.12

621

2.86

0.08

0.29

0.048

Interviewer/facilitator

2218

91%

0.56

771

0.51

0.02

1187

0.58

0.01

0.08

0.001**

Credentials

1227

50%

0.42

379

0.41

0.03

708

0.42

0.02

0.01

0.788

Occupation

2092

85%

0.43

730

0.43

0.02

1121

0.41

0.01

−0.02

0.372

Gender

1300

53%

0.43

460

0.38

0.02

685

0.45

0.02

0.07

0.026*

Experience and training

2262

92%

0.25

799

0.20

0.01

1200

0.26

0.01

0.06

0.001**

Relationship established

2193

90%

0.18

757

0.18

0.01

1181

0.18

0.01

0.00

0.836

Participant knowledge of the interviewer

1022

42%

0.16

308

0.15

0.02

603

0.16

0.02

0.01

0.581

Interviewer characteristics

922

38%

0.20

236

0.16

0.02

585

0.23

0.02

0.07

0.020*

DOMAIN II: STUDY DESIGN

1117

8.31

351

7.97

0.15

645

8.51

0.10

0.55

0.007*

Methodological orientation and Theory

1206

49%

0.72

391

0.70

0.02

662

0.74

0.02

0.03

0.258

Sampling

2337

95%

0.77

815

0.73

0.02

1247

0.79

0.01

0.06

0.003*

Method of approach

2241

92%

0.71

785

0.66

0.02

1195

0.74

0.01

0.08

0.000**

Sample size

2384

97%

0.95

838

0.94

0.01

1259

0.96

0.01

0.02

0.023*

Non-participation

2229

91%

0.42

769

0.39

0.02

1203

0.45

0.01

0.06

0.008*

Setting of data collection

2377

97%

0.67

833

0.65

0.02

1258

0.67

0.01

0.02

0.339

Presence of nonparticipants

2237

91%

0.24

772

0.20

0.01

1207

0.26

0.01

0.06

0.001**

Description of sample

2394

98%

0.88

848

0.83

0.01

1259

0.90

0.01

0.07

0.000**

Interview guide

2329

95%

0.72

817

0.66

0.02

1234

0.77

0.01

0.12

0.000**

Repeat interviews

2195

90%

0.30

769

0.34

0.02

1177

0.28

0.01

−0.06

0.005*

Audio/visual recording

2262

92%

0.79

782

0.70

0.02

1219

0.83

0.01

0.13

0.000**

Field notes

2314

95%

0.33

814

0.29

0.02

1224

0.34

0.01

0.05

0.022*

Duration

2288

93%

0.61

793

0.57

0.02

1223

0.63

0.01

0.06

0.007*

Data saturation

2157

88%

0.29

753

0.20

0.01

1147

0.35

0.01

0.16

0.000**

Transcripts returned

1450

59%

0.13

494

0.11

0.01

789

0.15

0.01

0.04

0.028*

DOMAIN III: ANALYSIS AND FINDINGS

1086

5.94

339

5.42

0.10

625

6.20

0.07

0.78

0.000**

Number of data coders

2304

94%

0.60

785

0.49

0.02

1248

0.66

0.01

0.17

0.000**

Description of the coding tree

1333

54%

0.43

474

0.39

0.02

703

0.47

0.02

0.08

0.004*

Derivation of themes

2298

94%

0.80

800

0.74

0.02

1222

0.84

0.01

0.10

0.000**

Software

2312

94%

0.39

801

0.28

0.02

1234

0.45

0.01

0.17

0.000**

Participant checking

2259

92%

0.19

775

0.19

0.01

1225

0.19

0.01

0.01

0.752

Quotations presented

2384

97%

0.89

839

0.86

0.01

1260

0.92

0.01

0.06

0.000**

Data and findings consistent

2187

89%

0.77

749

0.72

0.02

1186

0.79

0.01

0.08

0.000**

Clarity of major themes

1085

44%

0.94

335

0.90

0.02

611

0.95

0.01

0.05

0.009*

Clarity of minor themes

993

41%

0.65

309

0.62

0.03

565

0.66

0.02

0.04

0.303

TOTAL COREQ SCORE

831

16.99

232

15.51

0.31

509

17.74

0.20

2.23

0.000**