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ORIGINAL RESEARCH
Transperineal Sonographic Anal Sphincter Complex Evaluation in Chronic Anal Fissures Elsaid M. Bedair, MD, Hany M. El Hennawy, MD, Ahmed Abdu Moustafa, MD, Gad Youssef Meki, MD, Bosat Elwany Bosat, MD Objectives—The purpose of this study was to assess the role of transperineal sonography in assessment of pathologic changes to the anal sphincter complex in patients with chronic anal fissures. Methods—We conducted a prospective case-control study of 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013 (group A) and 50 healthy volunteers (group B). Results—The most common patterns of radiologic changes to anal sphincters associated with chronic anal fissures were circumferential thickening of the anal sphincter complex in 5 patients (5%), circumferential thickening of the internal anal sphincter in 3 patients (3%), preferential thickening of the internal anal sphincter at the 6-o’clock position in 80 patients (80%) and the 12-o’clock position in 7 patients (7%), preferential thickening of the internal and external anal sphincters in 3 patients (3%), and thinning of the internal anal sphincter in 2 patients (2%). Conclusions—Chronic anal fissures cause differential thickening of both internal and external anal sphincters, with a trend toward increased thickness in relation to the site of the fissure. Routine preoperative transperineal sonography for patients with chronic anal fissures is recommended, and it is mandatory in high-risk patients. Key Words—chronic anal fissure; gastrointestinal ultrasound; sphincterotomy; transperineal sonography Received December 6, 2013, from the Department of Radiology, Al Khor Hospital, Hamad Medical Corporation, Al Khor, Qatar (E.M.B.); Department of Surgery, Hamad General Hospital, Hamad Medical Corporation, Doha, Qatar (H.M.E.H.); and Department of Surgery, Faculty of Medicine for Girls, Al Azhar University, Cairo, Egypt (A.A.M., G.Y.M., B.E.B.). Revision requested January 3, 2014. Revised manuscript accepted for publication March 7, 2014. Address correspondence to Hany M. El Hennawy, MD, Section of Transplantation, Department of General Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157 USA. E-mail: [email protected] Abbreviations
3D, 3-dimensional; 2D, 2-dimensional doi:10.7863/ultra.33.11.1981
E
ndoanal sonography is the current reference standard for diagnosing anatomic anal sphincter disruption and identifying occult anal sphincter injury.1–4 It has been shown to have sensitivity and specificity of 100% for diagnosing external anal sphincter damage and sensitivity of 100% and specificity of 95.5% for diagnosing internal anal sphincter damage.5,6 However, disadvantages of endoanal sonography include the requirement for specialized equipment and its relative invasiveness.7 Transperineal sonography has been used to determine the type of imperforate anus and evaluate anal sphincter tears in obstetric patients.8–10 Three-dimensional (3D) endoanal sonography improves diagnostic confidence in detecting damage to the anal sphincter complex.11 Three-dimensional transperineal sonography provides the advantage of volume storage capability to shorten the examination time with the patient present, allows for later consultation if necessary, and makes the examination relatively operator independent.12
©2014 by the American Institute of Ultrasound in Medicine | J Ultrasound Med 2014; 33:1981–1989 | 0278-4297 | www.aium.org
3311jum_online_Layout 1 10/20/14 9:45 AM Page 1982
Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
Using 3D transperineal sonography, Valsky and Yagel13 found that 7.9% of patients had occult damage to the anal sphincter (Figures 1 and 2). The aim of this study was to examine the role of transperineal sonography for assessment of the anal sphincter anatomy and pathologic changes associated with chronic anal fissures, as we could not find any previous similar study.
Materials and Methods This study included 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013, had not responded to medical treatment, and underwent transperineal sonography (group A). We excluded patients with postoperative recurrent chronic anal fissures, acute anal fissures on top of chronic anal fissures, and histories of anorectal surgery. We also performed transperineal sonography on 50 healthy volunteers without chronic anal fissures or any other benign anorectal conditions as a control group (group B). The procedures followed were in accord with the ethical standards of the Committee on Human Experimentation of our institution. Written informed consent was obtained from all participants. Transperineal Sonographic Technique Transperineal sonography was done by a single senior consultant radiologist using Acuson Antares (Siemens AG, Erlangen, Germany) and LOGIQ 9 (GE Healthcare, Milwaukee, WI) ultrasound systems. With the patient in
Figure 1. Schematic cross-sectional view of the female pelvis. The dotted line is a schematic representation of the endopelvic fascia position and its interaction with the anterior vaginal wall. Compare with rendered sonograms.13 PVM indicates pubovisceral muscle. Reprinted with permission from Valsky and Yagel.13
1982
the dorsal lithotomy position, the radiologist placed a 7.5– 10-MHz endocavitary probe or a 3–5-MHz convex probe (in morbidly obese patients) against the perineal body in a transverse orientation to outline the axial anal structures, including the anal mucosa and submucosa and the internal and external anal sphincters, and to provide images that were comparable with those obtained by using an endoluminal probe. The delineated layers of the sphincters naturally have the same echogenic characteristics as those obtained by endoanal sonography, with relatively poor delineation of the perineal body. Rotation of the probe through 180° defines a sagittal view of the anal canal and anorectal junction, showing the hypoechoic internal anal sphincter encircling the echogenic irregularity of the anal mucosa, as well as the completeness of the outer hyperechoic ring reflecting the external anal sphincter and puborectalis.14 The entire anal canal could be scanned by changing the probe’s inclination. A defect was defined as any discontinuity in the normal appearance of the sonographic texture of the internal or external anal sphincter. The images were orientated such that anterior was at the 12-o’clock position. The sphincter thickness was assessed at the 3- to 6- and 9- to 12-o’clock positions at 3 levels (lower, middle, and upper anal).15 In this study, we followed the cutoff values proposed by Pascual et al,16 who stated that the internal anal sphincter thickness was considered increased when it was greater than 2.5 mm in patients younger than 50 years and greater than 3 mm in patients 50 years or older. A true sphincter defect will be seen in all planes, whereas an artifact will not. Figure 2. Schematic diagram of the anal sphincter complex. DL indicates dentate line; ES, external sphincter; IS, internal sphincter; LAM, levator ani muscle; and 1, 2, and 3, subcutaneous, superficial, and deep portions of the external sphincter, respectively. Reprinted with permission from Valsky and Yagel.13
J Ultrasound Med 2014; 33:1981–1989
3311jum_online_Layout 1 10/20/14 9:45 AM Page 1983
Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
Statistical Analysis Categorical and continuous values were expressed as frequency (percentage), mean ± standard deviation, and range. Descriptive statistics were used to summarize all demographic and other characteristics of the participants. Quantitative variable means measured at different time points were compared by repeated measure analysis of variance. A paired t test or Wilcoxon signed rank test was used to compare means of the quantitative variables measured at 2 different time points. Quantitative variables means between 2 and more than 2 independent groups were analyzed by a t test and 1-way analysis of variance. Where an overall group difference was found to be statistically significant, pair-wise comparisons were made by using the appropriate post hoc test. Associations between 2 or more qualitative variables were assessed by a χ2 test. For small-cell frequencies, a χ2 test with a continuity correction factor was used. In case assumptions from the parametric test were not fulfilled, a corresponding nonparametric test was used. Pictorial presentations of the key findings were made with appropriate statistical graphs. All tests were 2 sided, and P < .05 was considered statistically significant. All statistical analyses were done with the SPSS 19.0 statistical package (IBM Corporation, Armonk, NY).
Results Group A included 100 patients aged 17 to 63 years (mean age ± SD, 34 ± 10.5 years; 62 male and 38 female) who had chronic anal fissures that did not respond to medical treatment and underwent transperineal sonography. Group B included 50 healthy volunteers aged 24 to 51 years (mean age, 31 ± 11.5 years; 28 male and 22 female). The demographic and basic clinical characteristics of both groups are detailed in Table 1. The mean transperineal sonography duration was 13.5 ± 1.5 minutes. Sphincter Measurements in Healthy Volunteers Transperineal sonographic sphincter measurements in group B included mean internal anal sphincter thicknesses at the lower anal canal of 2.63, 2.69, 2.65, and 2.69 mm at the 3-, 6-, 9-, and 12-o’clock positions, respectively, and the mean length was 2.49 cm. The mean external anal sphincter thicknesses were 4.27, 4.28, 4.28, and 4.30 mm at the 3-, 6-, 9-, and 12-o’clock measurement points, and the mean length was 2.31 cm. Detailed measurements for both groups are presented in Table 2.
Sonographic Findings in Patients With Chronic Anal Fissures Transperineal sonographic findings in group A (Figure 3) included 6 external anal sphincter defects, 3 external anal sphincter sinuses, 4 polyps, 7 collections/abscesses, 3 granulomatous lesions, 5 perianal fistula, and 9 third- to fourthdegree hemorrhoids. External anal sphincter defects were found in 6 patients; 4 defects were at the 12-o’clock position, 1 at the 3-o’clock position, and 1 at the 6-o’clock position. The sizes of the defects ranged from 3 to 5 mm. One defect was associated with a collection and 1 with an anterior anal fissure. Five defects were located within the lower third of the external anal sphincter. The last defect extended to the middle third. Of the 7 collections/abscesses, 4 were within the external anal sphincter with an underlying defect and perisphencteric extension; 1 was extrasphincteric; in 1, the external anal sphincter could not be identified, and 1 was abutting the internal anal sphincter and involved the external anal sphincter.
Table 1. Clinical and Demographic Characteristics of Patients With Chronic Anal Fissures (Group A) and Control Participants (Group B) Characteristic Male/female Age, y 60 Medical history Duration of symptoms, mo 1–3 3–6 >6 Chronic medical conditions Diabetes Hypertension Obstetric history Nulliparous Multiparous Clinical examination Fissure location Anterior Posterior Fissure length, cm 1 Severe anal spasms Associated hemorrhoids
Group A
Group B
62/38
28/22
0 (0) 23 (23) 45 (45) 18 (18) 14 (14) 0 (0)
0 (0) 20 (40) 14 (28) 12 (24) 0 (0) 4 (8)
10 (10) 82 (82) 8 (8) 5 (5) 4 (4)
2 (4) 1 (2)
2 (2) 6 (6)
4 (8) 8 (16)
7 (7) 93 (93) 54 (54) 46 (46) 6 (6) 9 (9)
Values in parentheses are percentages.
J Ultrasound Med 2014; 33:1981–1989
1983
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Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
The most common patterns of radiologic changes to anal sphincters in chronic anal fissures (Figure 4) included the following: (1) circumferential thickening of both the internal and external anal sphincters in 5 patients (5%); (2) circumferential thickening of the internal anal sphincter in 3 patients (3%); (3) preferential thickening of the internal anal sphincter at the 6o’clock position in 80 patients (80%); (4) preferential thickening of the internal anal sphincter at the 12-o’clock position in 7 patients (7%); (5) preferential thickening of the internal and external anal sphincters in 3 patients (3%); and (6) thinning of the internal anal sphincter in 2 patients (2%). The mean internal anal sphincter thicknesses at the lower anal canal in group A were 3.14, 3.61, 3.19, and 3.19 mm at the 3-, 6-, 9-, and 12-o’clock positions, respectively, and the mean length was 2.66 cm. The mean external anal sphincter thicknesses were 4.66, 4.88, 4.64, and 4.70 mm at the 3-, 6-, 9-, and 12-o’clock measurement points, and the mean length was 2.13 cm.
Internal Anal Sphincter Measurement Changes in Chronic Anal Fissures There was generalized diffuse thickening of the entire internal anal sphincter at all levels of the anal canal compared to the healthy volunteers (Figure 5). Upper Anal Canal Generalized internal anal sphincter thickening was observed at the 4 measurement points. The mean internal anal sphincter thickness at the 6-o’clock position was significantly greater (3.47) compared to those at the 3-, 9-, and 12-o’clock positions (2.99, 3.01, and 3.05, respectively). The overall 2-tailed P values were
ORIGINAL RESEARCH
Transperineal Sonographic Anal Sphincter Complex Evaluation in Chronic Anal Fissures Elsaid M. Bedair, MD, Hany M. El Hennawy, MD, Ahmed Abdu Moustafa, MD, Gad Youssef Meki, MD, Bosat Elwany Bosat, MD Objectives—The purpose of this study was to assess the role of transperineal sonography in assessment of pathologic changes to the anal sphincter complex in patients with chronic anal fissures. Methods—We conducted a prospective case-control study of 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013 (group A) and 50 healthy volunteers (group B). Results—The most common patterns of radiologic changes to anal sphincters associated with chronic anal fissures were circumferential thickening of the anal sphincter complex in 5 patients (5%), circumferential thickening of the internal anal sphincter in 3 patients (3%), preferential thickening of the internal anal sphincter at the 6-o’clock position in 80 patients (80%) and the 12-o’clock position in 7 patients (7%), preferential thickening of the internal and external anal sphincters in 3 patients (3%), and thinning of the internal anal sphincter in 2 patients (2%). Conclusions—Chronic anal fissures cause differential thickening of both internal and external anal sphincters, with a trend toward increased thickness in relation to the site of the fissure. Routine preoperative transperineal sonography for patients with chronic anal fissures is recommended, and it is mandatory in high-risk patients. Key Words—chronic anal fissure; gastrointestinal ultrasound; sphincterotomy; transperineal sonography Received December 6, 2013, from the Department of Radiology, Al Khor Hospital, Hamad Medical Corporation, Al Khor, Qatar (E.M.B.); Department of Surgery, Hamad General Hospital, Hamad Medical Corporation, Doha, Qatar (H.M.E.H.); and Department of Surgery, Faculty of Medicine for Girls, Al Azhar University, Cairo, Egypt (A.A.M., G.Y.M., B.E.B.). Revision requested January 3, 2014. Revised manuscript accepted for publication March 7, 2014. Address correspondence to Hany M. El Hennawy, MD, Section of Transplantation, Department of General Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157 USA. E-mail: [email protected] Abbreviations
3D, 3-dimensional; 2D, 2-dimensional doi:10.7863/ultra.33.11.1981
E
ndoanal sonography is the current reference standard for diagnosing anatomic anal sphincter disruption and identifying occult anal sphincter injury.1–4 It has been shown to have sensitivity and specificity of 100% for diagnosing external anal sphincter damage and sensitivity of 100% and specificity of 95.5% for diagnosing internal anal sphincter damage.5,6 However, disadvantages of endoanal sonography include the requirement for specialized equipment and its relative invasiveness.7 Transperineal sonography has been used to determine the type of imperforate anus and evaluate anal sphincter tears in obstetric patients.8–10 Three-dimensional (3D) endoanal sonography improves diagnostic confidence in detecting damage to the anal sphincter complex.11 Three-dimensional transperineal sonography provides the advantage of volume storage capability to shorten the examination time with the patient present, allows for later consultation if necessary, and makes the examination relatively operator independent.12
©2014 by the American Institute of Ultrasound in Medicine | J Ultrasound Med 2014; 33:1981–1989 | 0278-4297 | www.aium.org
3311jum_online_Layout 1 10/20/14 9:45 AM Page 1982
Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
Using 3D transperineal sonography, Valsky and Yagel13 found that 7.9% of patients had occult damage to the anal sphincter (Figures 1 and 2). The aim of this study was to examine the role of transperineal sonography for assessment of the anal sphincter anatomy and pathologic changes associated with chronic anal fissures, as we could not find any previous similar study.
Materials and Methods This study included 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013, had not responded to medical treatment, and underwent transperineal sonography (group A). We excluded patients with postoperative recurrent chronic anal fissures, acute anal fissures on top of chronic anal fissures, and histories of anorectal surgery. We also performed transperineal sonography on 50 healthy volunteers without chronic anal fissures or any other benign anorectal conditions as a control group (group B). The procedures followed were in accord with the ethical standards of the Committee on Human Experimentation of our institution. Written informed consent was obtained from all participants. Transperineal Sonographic Technique Transperineal sonography was done by a single senior consultant radiologist using Acuson Antares (Siemens AG, Erlangen, Germany) and LOGIQ 9 (GE Healthcare, Milwaukee, WI) ultrasound systems. With the patient in
Figure 1. Schematic cross-sectional view of the female pelvis. The dotted line is a schematic representation of the endopelvic fascia position and its interaction with the anterior vaginal wall. Compare with rendered sonograms.13 PVM indicates pubovisceral muscle. Reprinted with permission from Valsky and Yagel.13
1982
the dorsal lithotomy position, the radiologist placed a 7.5– 10-MHz endocavitary probe or a 3–5-MHz convex probe (in morbidly obese patients) against the perineal body in a transverse orientation to outline the axial anal structures, including the anal mucosa and submucosa and the internal and external anal sphincters, and to provide images that were comparable with those obtained by using an endoluminal probe. The delineated layers of the sphincters naturally have the same echogenic characteristics as those obtained by endoanal sonography, with relatively poor delineation of the perineal body. Rotation of the probe through 180° defines a sagittal view of the anal canal and anorectal junction, showing the hypoechoic internal anal sphincter encircling the echogenic irregularity of the anal mucosa, as well as the completeness of the outer hyperechoic ring reflecting the external anal sphincter and puborectalis.14 The entire anal canal could be scanned by changing the probe’s inclination. A defect was defined as any discontinuity in the normal appearance of the sonographic texture of the internal or external anal sphincter. The images were orientated such that anterior was at the 12-o’clock position. The sphincter thickness was assessed at the 3- to 6- and 9- to 12-o’clock positions at 3 levels (lower, middle, and upper anal).15 In this study, we followed the cutoff values proposed by Pascual et al,16 who stated that the internal anal sphincter thickness was considered increased when it was greater than 2.5 mm in patients younger than 50 years and greater than 3 mm in patients 50 years or older. A true sphincter defect will be seen in all planes, whereas an artifact will not. Figure 2. Schematic diagram of the anal sphincter complex. DL indicates dentate line; ES, external sphincter; IS, internal sphincter; LAM, levator ani muscle; and 1, 2, and 3, subcutaneous, superficial, and deep portions of the external sphincter, respectively. Reprinted with permission from Valsky and Yagel.13
J Ultrasound Med 2014; 33:1981–1989
3311jum_online_Layout 1 10/20/14 9:45 AM Page 1983
Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
Statistical Analysis Categorical and continuous values were expressed as frequency (percentage), mean ± standard deviation, and range. Descriptive statistics were used to summarize all demographic and other characteristics of the participants. Quantitative variable means measured at different time points were compared by repeated measure analysis of variance. A paired t test or Wilcoxon signed rank test was used to compare means of the quantitative variables measured at 2 different time points. Quantitative variables means between 2 and more than 2 independent groups were analyzed by a t test and 1-way analysis of variance. Where an overall group difference was found to be statistically significant, pair-wise comparisons were made by using the appropriate post hoc test. Associations between 2 or more qualitative variables were assessed by a χ2 test. For small-cell frequencies, a χ2 test with a continuity correction factor was used. In case assumptions from the parametric test were not fulfilled, a corresponding nonparametric test was used. Pictorial presentations of the key findings were made with appropriate statistical graphs. All tests were 2 sided, and P < .05 was considered statistically significant. All statistical analyses were done with the SPSS 19.0 statistical package (IBM Corporation, Armonk, NY).
Results Group A included 100 patients aged 17 to 63 years (mean age ± SD, 34 ± 10.5 years; 62 male and 38 female) who had chronic anal fissures that did not respond to medical treatment and underwent transperineal sonography. Group B included 50 healthy volunteers aged 24 to 51 years (mean age, 31 ± 11.5 years; 28 male and 22 female). The demographic and basic clinical characteristics of both groups are detailed in Table 1. The mean transperineal sonography duration was 13.5 ± 1.5 minutes. Sphincter Measurements in Healthy Volunteers Transperineal sonographic sphincter measurements in group B included mean internal anal sphincter thicknesses at the lower anal canal of 2.63, 2.69, 2.65, and 2.69 mm at the 3-, 6-, 9-, and 12-o’clock positions, respectively, and the mean length was 2.49 cm. The mean external anal sphincter thicknesses were 4.27, 4.28, 4.28, and 4.30 mm at the 3-, 6-, 9-, and 12-o’clock measurement points, and the mean length was 2.31 cm. Detailed measurements for both groups are presented in Table 2.
Sonographic Findings in Patients With Chronic Anal Fissures Transperineal sonographic findings in group A (Figure 3) included 6 external anal sphincter defects, 3 external anal sphincter sinuses, 4 polyps, 7 collections/abscesses, 3 granulomatous lesions, 5 perianal fistula, and 9 third- to fourthdegree hemorrhoids. External anal sphincter defects were found in 6 patients; 4 defects were at the 12-o’clock position, 1 at the 3-o’clock position, and 1 at the 6-o’clock position. The sizes of the defects ranged from 3 to 5 mm. One defect was associated with a collection and 1 with an anterior anal fissure. Five defects were located within the lower third of the external anal sphincter. The last defect extended to the middle third. Of the 7 collections/abscesses, 4 were within the external anal sphincter with an underlying defect and perisphencteric extension; 1 was extrasphincteric; in 1, the external anal sphincter could not be identified, and 1 was abutting the internal anal sphincter and involved the external anal sphincter.
Table 1. Clinical and Demographic Characteristics of Patients With Chronic Anal Fissures (Group A) and Control Participants (Group B) Characteristic Male/female Age, y 60 Medical history Duration of symptoms, mo 1–3 3–6 >6 Chronic medical conditions Diabetes Hypertension Obstetric history Nulliparous Multiparous Clinical examination Fissure location Anterior Posterior Fissure length, cm 1 Severe anal spasms Associated hemorrhoids
Group A
Group B
62/38
28/22
0 (0) 23 (23) 45 (45) 18 (18) 14 (14) 0 (0)
0 (0) 20 (40) 14 (28) 12 (24) 0 (0) 4 (8)
10 (10) 82 (82) 8 (8) 5 (5) 4 (4)
2 (4) 1 (2)
2 (2) 6 (6)
4 (8) 8 (16)
7 (7) 93 (93) 54 (54) 46 (46) 6 (6) 9 (9)
Values in parentheses are percentages.
J Ultrasound Med 2014; 33:1981–1989
1983
3311jum_online_Layout 1 10/20/14 9:45 AM Page 1984
Bedair et al—Anal Sphincter Complex Evaluation in Chronic Anal Fissures
The most common patterns of radiologic changes to anal sphincters in chronic anal fissures (Figure 4) included the following: (1) circumferential thickening of both the internal and external anal sphincters in 5 patients (5%); (2) circumferential thickening of the internal anal sphincter in 3 patients (3%); (3) preferential thickening of the internal anal sphincter at the 6o’clock position in 80 patients (80%); (4) preferential thickening of the internal anal sphincter at the 12-o’clock position in 7 patients (7%); (5) preferential thickening of the internal and external anal sphincters in 3 patients (3%); and (6) thinning of the internal anal sphincter in 2 patients (2%). The mean internal anal sphincter thicknesses at the lower anal canal in group A were 3.14, 3.61, 3.19, and 3.19 mm at the 3-, 6-, 9-, and 12-o’clock positions, respectively, and the mean length was 2.66 cm. The mean external anal sphincter thicknesses were 4.66, 4.88, 4.64, and 4.70 mm at the 3-, 6-, 9-, and 12-o’clock measurement points, and the mean length was 2.13 cm.
Internal Anal Sphincter Measurement Changes in Chronic Anal Fissures There was generalized diffuse thickening of the entire internal anal sphincter at all levels of the anal canal compared to the healthy volunteers (Figure 5). Upper Anal Canal Generalized internal anal sphincter thickening was observed at the 4 measurement points. The mean internal anal sphincter thickness at the 6-o’clock position was significantly greater (3.47) compared to those at the 3-, 9-, and 12-o’clock positions (2.99, 3.01, and 3.05, respectively). The overall 2-tailed P values were
