Study reference

Study characteristics

Patient characteristics

Index test

(test of interest)

Reference test

Follow-up

Outcome measures and effect size

Comments

Beer-Gabel, 2015

Type of study[1]:

Retrospective cohort

Setting:

Single centre

Country:

Israel

Conflicts of interest:

Not reported

Inclusion criteria:

Adult females with fecal incontinence (solid or liquid fecal incontinence more than once a month) or chronic constipation with a score of 15 or higher on the Cleveland Constipation Severity Index

-attending the hospital during the years 2011-2013

Exclusion criteria:

Not mentioned

N=105

Prevalence:

42% of the included patients was diagnosed with intussusception based on the reference standard

Mean age ± SD:

56 ± 11

Sex: 100 % F

Other important characteristics:

Mean parity ± SD

2.8 (1.2)

Chronic constipation:

81 patients (mean age 54.6 ± 11 years)

Fecal incontinence: 24 patients (mean age 60 ± 12 years)

Describe index test:

Dynamic transperineal ultrasound (DTP-US)

The examination was performed while the patient was lying in the left lateral position at rest, at squeeze and at straining.

Cut-off point(s):

Defined as present or absent. Intussusception was defined as folding of the rectum into either the rectum (recto-rectal) or in contact with the anus (recto-anal) or penetrating to the anal canal (intra-anal)

Describe reference test[2]:

Defecography (120 mL barium paste instilled into the rectum using conventional videofluroscopy while the patient was in the lateral sitting position at rest and during evacuation

Cut-off point(s):

Defined as present or absent. Intussusception was defined as folding of the rectum into either the rectum (recto-rectal) or in contact with the anus (recto-anal) or penetrating to the anal canal (intra-anal)

Time between the index test and reference test:

Not mentioned

For how many participants were no complete outcome data available?

N (%) 0 (0%)

Reasons for incomplete outcome data described? Not applicable

Outcome measures and effect size (include 95%CI and p-value if available)⁴:

Intussusception:

Sensitivity: 82%

Specificity: 84%

Positive Predictive Value: 80%

Negative Predictive Value: 86.7%

Agreement (proportions of true results obtained by DTP-US in all the patients that had DEF performed; True positives + true negativersus / total): 83%

Intussusception in constipated subgroup:

Sensitivity: 84%

Specificity: 85%

Agreement: 84%

Intussusception in fecal incontinence subgroup:

Sensitivity: 91%

Specificity: 77%

Agreement: 82%

It was not possible to calcalute PPV and NPV for the subgroups, since no specific data were reported.

Rectal prolaps:

Sensitivity: 75%

Specificity: 97%

Rectal prolaps in constipated subgroup:

Sensitivity: 80%

Specificity: 100%

Rectal prolaps in fecal incontinence group:

Sensitivity: 50%

Specificity: 89%

Defecography as reference standard, which is not as sensitive and specific as surgery

Faucheron, 2014

Type of study:

Prospective cohort

Setting:

Single centre

Country:

France

Conflicts of interest:

None

Inclusion criteria:

Female patients with posterior pelvic floor prolapse who needed surgery

Exclusion criteria:

17 patients who had previously undergone surgery for pelvic prolapse during the same period

N=50

Prevalence:

34% of the included patients was diagnosed with intussusception based on the reference standard

Median age (range):

53 (31-81)

Sex: 100% F

Other important characteristics:

Median parity (range)

3 (0-8) (one patients was nulliparous)

All patients had symptoms for many years, 46% had symptoms for more than 5 years

Obstructed defecation n (%)

50 (100%)

Anal incontinence or soiling n (%)

17 (34%)

Previously undergone hysterectomy: n (%) 24 (48%)

BMI>25kg/m2: n (%) 11 (22%)

Raised transit time constipation: n (%) 14 (28%)

Dyspareunia: n (%) 10 (20%)

Pain on defecation: 2 (4%)

Undergone biofeedback n(%): 50 (100%)

Used rectal irrigation: n (%)

16 (32%)

Suppositories n(%): 15 (30%)

Both n(%): 8 (16%)

Describe index test:

Dynamic cystocolpoproctography (DCP)

Lateral radiographs and a videotape with patients in the sitting position were obtained at rest, on squeeze and during and after evacuation. After rectal and bladder emptying at the end of the examination, further radiographs were taken with the patient straining maximally to show the full extent of the prolapse.

Cut-off point(s):

Defined as present or absent, not clearly described.

Comparator test:

Functional pelvic MRI with the patient in supine position. Morphological analysis of the patient at rest, contraction of the pelvic floor muscles, followed by relaxation, straining and rectal evacuation and an post-evacuation phase.

Cut-off point(s):

Defined as present or absent, not clearly described.

Describe reference test:

Surgery

Cut-off point(s):

Defined as present or absent, not clearly described.

Time between the index test and reference test:

Not reported

For how many participants were no complete outcome data available?

N (%) 0 (0%)

Reasons for incomplete outcome data described?

Not applicable

MRI:

Sensitivity (95% CI)

0.647 (0.411 to 0.827)

Specificity (95%CI)

1.0     (0.873 to 1.0)

Youden’s index (95%CI)

0.633 (0.411 to 0.827)

DCP:

Sensitivity (95% CI)

0.882 (0.642 to 0.977)

Specificity (95%CI)

1.0     (0.873 to 1.0)

Youden’s index (95%CI)

0.833 (0.642 to 0.977)

McNemar: p=0.125 for sensitivity

All patients had symptoms for many years and all patients had undergone biofeedback

Steensma, 2010

Type of study:

Prospective observational study

Setting:

Single centre

Country:

Netherlands

Conflicts of interest:

None reported

Inclusion criteria:

All women with symptoms (pelvic discomport, OD, FI or a combination) related to posterior compartment prolapse referred to the centre between September 2005 and July 2007

Exclusion criteria:

Not mentioned

N=75

Prevalence:

36% of the included patients was diagnosed with intussusception based on the reference standard

Median age (range):

59 (22 to 83)

Sex: 100% F

Other important characteristics:

Previously undergone hysterectomy:

n (%) 31 (41%)

Previous pelvic organ prolapse repair

N (%): 37 (49%)

Median parity (range)

2 (0 to 10); 4 nulliparous)

Symptoms reported by patients: n(%)

Stress urinary incontinence: 38 (51%)

Urge urinary continence 25 (33%)

Pelvic discomfort: 50 (67%)

Obstructed defecation: 36 (48%)

Fecal incontinence: 26 (35%)

Describe index test:

3DTransperineal ultrasound (3DTPUS)

Patients were examined after voiding and in the supine position. 2D cine loop volumes (3D) were obtained at rest, during levator contraction and during maximal Valsalva manoeuvre.

Cut-off point(s):

Defined as present or absent. Infolding of the rectal wall into the rectum or anus=presence of intussusception

Comparator test:

Cut-off point(s):

Describe reference test:

Evacuation proctography (EP), imaging was acquired at rest, during pelvic floor contraction and during straining and a video recording was obtained during evacuation of contrast

Cut-off point(s):

Defined as present or absent. Infolding of the rectal wall into the rectum or anus=presence of intussusception

Time between the index test and reference test:

Maximum of 6 months

For how many participants were no complete outcome data available?

N (%): 0 (0%)

Reasons for incomplete outcome data described?

Not applicable

Sensitivity: 22%

Specificity: 96%

PPV: 75% (6/8)

NPV: 68.7% (46/67)

Agreement between two tests (cohens kappa): 0.21

Patient reported outcome measures

85% (64 patients) responded to the questionnaire)

VAS discomfort (scale 0-10)

Median (range)

3DUPTS: 1 (0-9)

EP: 4 (0-10)

P<0.001

87% of the patients regarded the EP as less tolerated investigation compared with 3DTPUS;

8% regarded 3DTPUS as less tolerated compared with EP

(p<0.001)

Significantly more patients preferred to have a repeat ultrasound than an evacuation proctogram (p<0.003), not further specified.

Weemhoff, 2013

Type of study:

Prospective observational study

Setting:

Single centre

Country:

Netherlands

Conflicts of interest:

None (no financial support, no conflicts of interest)

Inclusion criteria:

Women with complaints of fecal incontinence or obstructed defecation who were scheduled to undergo a diagnostic evacuation proctography between April 2007 and February 2008

Exclusion criteria:

-age <18 year

-legally incapable patients

-persons not able to understand the information given

N=50

Prevalence:

32% of the included patients was diagnosed with intussusception based on the reference standard

Mean age (range): 59 (28-95)

Sex: 100% F

Other important characteristics:

Fecal incontinence %: 84% (n=42)

Obstructed defecation%: 16% (n=8)

Describe index test:

Transperineal ultrasound

Patient was in supine position with slightly flexed legs. Imaging was acquired at rest, during contraction and during straining. At least three Valsalva manoeuvres were recorded as cineloop and the best of these manoeuvres was used for evaluation.

Cut-off point(s):

Defined as present or absent. Intussusception was defined as invagination of the proximal rectal wall during defecation.

Comparator test:

Not applicable

Cut-off point(s):

Not applicable

Describe reference test:

Evacuation proctography

Imaging was performed at rest, during contraction and during straining and evacuation of the contrast

Cut-off point(s):

Defined as present or absent. Invagination of the proximal rectal wall during defecation=presence of intussusception

Time between the index test and reference test:

Not clearly described, probably on the same day

For how many participants were no complete outcome data available?

N (%) 0 (0%)

Reasons for incomplete outcome data described?

Not applicable

Sensitivity: 25% (95%CI: 7 to 52%)

Specificity: 100% (95%CI: 90% to 100%)

Positive predictive value (95%CI): 1.00 (0.4 to 1.0)

Negative predictive value (95%CI): 0.74 (0.59 to 0.86)

Regadas, 2011

Type of study:

Prospective observational study

Setting:

Multi-centre (six centres)

Country:

Brazil, Texas, Florida, Venezuela

Conflicts of interest:

None reported

Inclusion criteria:

-women presenting with obstructed defecation symptoms from January 2009 to October 2009

Exclusion criteria:

-patients with previous anorectal and vaginal surgery, fecal incontinence and/or previous anorectal radiation

N=86

Prevalence: 48,8% of the included patients was diagnosed with intussusception based on the reference standard

Median age (range): 53.4 (26-77). 13 patients (15.1%) were under the age of 50 years.

Sex: 100% F

Other important characteristics:

Median Wexner score (range): 13.4 (6-23)

Nulliparous n(%)

16 (18.6%)

Vaginal deliveries n(%):

40 (46.5%)

Cesarean section n(%): 30 (34.9%)

Describe index test:

Echodefecography: 360° 3D transducer, 3 scans.

Patients were examined in the left lateral position after rectal enema

Cut-off point(s):

Defined as present or absent.

Observation that the rectal wall layers protruded the rectal lumen.

Comparator test:

Not applicable

Cut-off point(s):

Not applicable

Describe reference test:

Defecography

Images were taken both at rest and during straining. (lateral visualization of the anal canal and rectum.

Cut-off point(s):

Defined as present or absent. Invagination of the rectal wall occurring during straining but not passing through the anal canal=presence of intussusception

Time between the index test and reference test: not reported

For how many participants were no complete outcome data available?

N (%): 0 (0%)

Reasons for incomplete outcome data described? Not applicable

Sensitivity: 88.1%

Specificity: 90.9%

Positive predictive value: 90.2%

Negative predictive value: 88.9%

Agreement between two tests (cohens kappa, 95%CI)

0.79, 0.57 to 1.0

All examiners had previous experience with anorectal ultrasound and participated in a 3-day session on echodefecography (at least 10 echodefecographies under supervision of an experienced examiner).

Perniola, 2008

Type of study:

Prospective cohort

Setting:

Single centre

Country:

Australia

Conflicts of interest:

None reported

Inclusion criteria:

Women scheduled to undergo defecation proctography for the clinical diagnosis of obstructed defecation between October 2005 to March 2007

Exclusion criteria:

Not specified

N=37

Prevalence:

76.7% (23/30 patients) of the included patients was diagnosed with intussusception based on the reference standard.

Mean age (range): 53 (26-80); No SD reported

Sex: 100 % F

Other important characteristics (total n=37):

Median vaginal parity (range): 2 (0-6); six patients were nulliparous

Mean age at first delivery (range): 24 (17-39)

Ten women (27%) had a previous hysterectomy; 4 (11%) repair of a vaginal prolapse. 2 had previously undergone surgery for OD.

Symptoms n (%)

Constipation: 26 (70%)

Straining at stool: 31 (84%)

Vaginal digitation: 15 (41%)

Sensation of incomplete emptying: 30 (81%)

Fecal incontinence: 10 (27%)

Vaginal lump: 10(27%)

Describe index test:

Ultrasonography (translabial ultrasound), no contrast medium was used.

The test was performed after voiding, supine, at rest and on maximal Valsalva manoeuvre.

Cut-off point(s):

Defined as present or absent. A rectal intussusception was defined as a full thickness invagination of the rectal wall into the anal canal

Comparator test:

Not applicable

Cut-off point(s): Not applicable

Describe reference test:

Defecation proctography

Images were acquired at rest, during straining, defecation and coughing; the procedure was videotaped.

Cut-off point(s):

Defined as present or absent. Not further specified

Time between the index test and reference test:

Not reported

For how many participants were no complete outcome data available?

N (%) 7 (19%)

Reasons for incomplete outcome data described?

Yes: one patients was found to be pregnant and five cancelled repeatedly their scheduled defecation proctography . One patient had an incomplete proctogram owing to inability to defecate, allowing only assessment for rectocele.

Diagnostic accuracy:

Sensitivity: 30.4%

Specificity: 85.7%

Positive predictive value: 0.88 (95%CI: 0.61 to 0.98)

Negative predictive value: 0.27 (95%CI: 0.18 to 0.31)%

Agreement between two tests: cohen’s kappa for IRP/prolapse: 0.09

Discomfort:

No questionnaire/scale specified;

Median (interquartile range; range):

Ultrasound: 1 (0-2; 0-10)

Defecography: 7 (3-9; 0-10)

P<0.001

Not all patients had both ultrasonography and defecography.

Ultrasonogprahy: n=37

Defecography: n=30 (81%)

Grasso, 2007

Type of study:

Consecutive cohort

Setting:

Single centre

Country:

Italy

Conflicts of interest:

None reported

Inclusion criteria:

-women with either fecal incontinence or obstructive defecation

-no history of vaginal surgery or prolapse

-refferal between October 2004 and May 2005

Exclusion criteria:

-

N=43

Prevalence: 51% (22/43 patients) of the included patients was diagnosed with intussusception based on the reference standard. Of the 22 patients, 15 had symptomatic IRP complaints.

Median age (range): 58 (20-79)

Sex: 100% F

Other important characteristics:

Median BMI (range): 23.7 (17,8-40.7)

Median number of vaginal deliveries (range): 3 (0-5). Six women were nulliparous

Rectocele: 86% (37/43)

Fecal incontinence: 16% (7/43)

Dyssynergia: 14% (6/43)

Sigmoidocele: 21% (9/43)

Stress incontinence:

26% (11/43)

Describe index test:

introital ultrasound (transperineal echography) in a semi-recumbent position (110° sitting angle) in a gynaecological chair with legs flexed and opened.

Four images were acquired: axial view, sagittal view at rest and during squeezing and during sustained straining.

Cut-off point(s):

Defined as present or absent.

Intussusception was diagnosed on sagittal scans if there was an infolding of the hypoechoic anterior and posterior rectal walls during straining

Comparator test:

Not applicable

Cut-off point(s):

Not applicable

Describe reference test:

Colpocystodefecography (CCD) with contrast medium.

CCDimages were acquired with the patient in the horizontal lateral position at rest. Then, with the patient in the seated position on a special commode, lateral films were acquired at rest and during squeezing and straining manoeuvres. The evacuation phase was used to study the presence of intussusception; a post-evacuation X-ray was obtained at maximal straining

Cut-off point(s):

Defined as present or absent. Intussusception was diagnosed with standard criteria; intrarectal or intranal (not further specified).

Time between the index test and reference test:

Not described

For how many participants were no complete outcome data available?

N (%) 0 (0%)

Reasons for incomplete outcome data described?

Not applicable

Sensitivity: 90.9%

Specificity: 100%

Positive predictive value: 100%

Negative predictive value: 91.3%

Agreement between two tests (cohens kappa, 95%CI) 0.91 (p <005)

Study reference

Patient selection

Index test

Reference standard

Flow and timing

Comments with respect to applicability

Beer-Gabel, 2015

Was a consecutive or random sample of patients enrolled?

Unclear

Was a case-control design avoided?

Unclear

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes, all exams were performed and interpreted by a single physician who was blinded to the results of the other test.

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes, all exams were performed and interpreted by a single physician who was blinded to the results of the other test.

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes, only women were included and patients with complaints of all compartments were included.

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: Low

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: High

CONCLUSION

Could the patient flow have introduced bias?

RISK: Unclear

Faucheron, 2014

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

Yes

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes, all patients had complaints for many years and had already received biofeedback

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: LOW

CONCLUSION

Could the patient flow have introduced bias?

RISK: LOW

Steensma, 2010

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Unclear

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

No, the interval was 6 months

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

No

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: HIGH

CONCLUSION

Could the patient flow have introduced bias?

RISK: High

Weemhoff, 2012

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

No

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: High

CONCLUSION

Could the patient flow have introduced bias?

RISK: Unclear

Regadas, 2011

Was a consecutive or random sample of patients enrolled?

Unclear

Was a case-control design avoided?

Unclear

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

Yes, only patients with OD symptoms, FI was excluded

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: High

CONCLUSION

Could the patient flow have introduced bias?

RISK: LOW

Perniola, 2008

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Unclear

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

No, 19% (n=7) did not receive a reference standard

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

No

Are there concerns that the included patients do not match the review question?

No

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: UNCLEAR

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: High

CONCLUSION

Could the patient flow have introduced bias?

RISK: HIGH

Grasso, 2007

Was a consecutive or random sample of patients enrolled?

Yes

Was a case-control design avoided?

Yes

Did the study avoid inappropriate exclusions?

Yes

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

No threshold was used

Is the reference standard likely to correctly classify the target condition?

No, it is an imperfect reference test

Were the reference standard results interpreted without knowledge of the results of the index test?

Yes

Was there an appropriate interval between index test(s) and reference standard?

Unclear

Did all patients receive a reference standard?

Yes

Did patients receive the same reference standard?

Yes

Were all patients included in the analysis?

Yes

Are there concerns that the included patients do not match the review question?

No

Are there concerns that the index test, its conduct, or interpretation differ from the review question?

No

Are there concerns that the target condition as defined by the reference standard does not match the review question?

No

CONCLUSION:

Could the selection of patients have introduced bias?

RISK: LOW

CONCLUSION:

Could the conduct or interpretation of the index test have introduced bias?

RISK: LOW

CONCLUSION:

Could the reference standard, its conduct, or its interpretation have introduced bias?

RISK: High

CONCLUSION

Could the patient flow have introduced bias?

RISK: UNCLEAR