Background
Methods
Literature search
Study selection and analysis
Data extraction
Study | Selectiona
| Confoundersb
| Outcomec
| Total star | Qualityd
|
---|---|---|---|---|---|
Xin et al. (2014) | * * | * | – | 3/6 | Satisfactory |
Zhao et al. (2011) | * * * | * | – | 4/6 | Good |
Dong et al. (2013) | * * | * | – | 3/6 | Satisfactory |
Yao et al. (2012) | * * | * | – | 3/6 | Satisfactory |
Lu et al. (2006) | * * | * * | – | 4/6 | Good |
Lee et al. (2014) | * * | * | – | 3/6 | Satisfactory |
Gonlachanvit & Patcharatrakul (2005) | * * | * | – | 3/6 | Satisfactory |
Kaboli et al. (2010) | * * * | * | * | 5/6 | Very good |
Shalmani et al. (2011) | * * * | * | * | 5/6 | Very good |
Roshandel et al. (2006) | * * | * | * | 4/6 | Good |
Randomized controlled trial study | Jayasimhan et al | Support for the authors judgment |
---|---|---|
1. Selective | + | Quote: “Subjects were randomized using the sealed envelope method to either the treatment or placebo group…The placebo sample was similar in appearance and composition…” |
a) Random sequence generation | ||
b) Allocation concealment | + | |
2) Performance | + | Quote: “Patients and researchers were blinded to the allocated groups and the treatment allocation was revealed at the end of the research, once analysis was done” Patient returned home and would be reviewed for the outcome in the next appoinment (after 7 days) |
a) Blinding of participants and personnel | ||
3) Detection | + | Unlikely the blinding could have been broken. Quote: “Follow-up was done at the end of the study period based on a questionnaire which includes symptomatic improvement and a stool diary” |
a) Blinding outcome assessment | ||
4) Attrition | + | Reasons for missing outcome data unlikely to be related to the true outcome. Quote: “A total of 120 subjects were recruited but 12 did not complete the study and were considered dropouts. Dropouts were due to loss to follow-up, consent withdrawal and non-compliance such as consuming <80% of the test samples, intake of antibiotics, laxatives or other probiotics during the treatment period” |
a) Incomplete outcome data | ||
5) Reporting bias | + | The study protocol is available and all of the study’s pre-specified primary and secondary outcomes that are of interest in the review have been reported in the pre-specified way. Quote: “The protocol was approved by the Institutional Review Board (IRB) of the University Malaya Medical Centre (Reference no: 866.59)…CONSORT diagram of patient recruitment and analysis” |
a) Selective reporting | ||
6) Other bias | ? | No description of what was defined by ‘normal diet’ which is an important risk of bias especially when this study consists of more than one ethnic and elderly population. |
Justification for risk of bias | + | Low risk of bias for most key domains |
Results
An overview of selected articles
Reference/ Country | Sample /Age | Settings | Study design | Sampling | Sample size (response rate) | Diagnostic criteria |
---|---|---|---|---|---|---|
Xin et al. (2014), China | Chronic constipation patient, 18–80 years old | One clinic | Cross-sectional | Purposive | 184 (100%): 166FC (Rome II) 174 FC (Rome III) | Rome II & Rome III |
Zhao et al. (2011), China | Adult, 18–80 years old | 5 regions of China | Cross-sectional | Randomized, stratified multistage | 16,078 (89%): 948FC 183 IBS-C | Rome II |
Dong et al. (2013), China | Volunteer students, 19–23 years old | One university | Cross-sectional | Random (study areas) | 4638 (92.76%): 253 FC | Rome III |
Yao et al. (2012), China | IBS patient, >20 years old | Three hospitals | Cross-sectional | Purposive | 754 (97.2%): 108 IBS-C | Rome III |
Lu et al. (2006),Taiwan | Volunteer adult, ≥20 years old | One hospital | Cross-sectional | Convenience | 2018 (70.4%): 172 FC 54 IBS-C | Rome II |
Lee et al. (2014), South Korea | Self-reported constipation adult, 20–89 years old | One National Health Screening Program | Cross-sectional | Random | 625 (74.9%) | Rome III |
Gonlachanvit & Patcharatrakul (2005), Thailand | Chronic constipation patients, 30 to 70 years old | One hospital | Cross-sectional | Purposive | 103FC (100%) | Rome II |
Jayasimhan et al. (2013), Malaysia | Outpatient, 20–78 years old | One clinic | Randomized-controlled trial | Purposive | 108FC (90%) | Rome III |
Kaboli et al. (2010), Iran | Households, ≥16 years old | 5 suburb cities in one province | Cross-sectional | Random (postal code) | 18,180 (92%): 459 FC | Rome III |
Shalmani et al. (2011), Iran | Households, ≥16 years old | 5 urban areas in one province | Cross-sectional | Cluster (postal code) | 18,180 (94%): 435 FC | Rome III |
Roshandel et al. (2006), Iran | Outpatient, >20 years old | One clinic | Cross-sectional | Purposive | 1023 (100%): 115 FC 32 IBS-C | Rome II |
Quality of selected studies
Symptoms of constipation
Symptom | Rank 1st | Rank 2nd | Rank 3rd | Rank 4th | Rank 5th | Rank 6th |
---|---|---|---|---|---|---|
Straining | 91.6% [25] 92.0% [25] 64.6% [32] 75.0% [27] 90.0% [29] 89.9% [30] 93.0% [33]
70.4% [22]
65.0% [27]
88.0% [28] | 95.7% [31] 79.3% [34] 70.3% [22] | 93.7% [26] | |||
Sensation incomplete evacuation | 72.1% [22] 96.5% [31] | 64.2% [32] 94.9% [26] 69.0% [28] 87.0% [33]
64.8% [22] | 74.1% [34] | 69.9% [25] 69.0% [25] 61.7% [29] 61.8% [30] | 31.0% [27]
38.0% [27] | |
Lumpy/hard stool | 93.1% [34] | 70.0% [27] 85.8% [29] 86.2% [30]
65.0% [27] | 71.1% [25] 71.3% [25] 77.0% [33] 95.7% [31]
63.0% [22] | 58.9% [32] 38.4% [22] 88.5% [26] | ||
Sensation of anorectal blockage | 53.5% [22] | 46.0% [27] 62.6% [31]
46.3% [22]
43.0% [27] | 53.0% [25] 52.3% [25] 39.5% [32] 87.7% [26] 26.6% [29] 26.2% [30] 31.0% [34] 48.0% [33] | |||
Infrequent defecations | 98.4% [26] | 74.7% [25] 74.7% [25] | 58.9% [32] 56.0% [27] 66.0% [29] 66.0% [30]
57.0% [27] | 32.8% [34] 57.0% [33] | 26.2% [22]
42.6% [22] | 57.4% [31] |
Manual maneuver | 18.1% [25] 18.4% [25] 14.8% [32] 47.0% [26] 10.0% [27] 26.1% [29] 16.3% [22] 16.1% [30] 53.9% [31] 15.5% [34] 45.0% [33]
11.1% [22]
10.0% [27] |
Comparison between FC and IBS-C
Symptoms | Percentage (%) |
p-value | Authors | |
---|---|---|---|---|
FC | IBS-C | |||
Straining | 75 | 65 | 0.005 | Zhao et al. (2011) |
70.3 | 70.4 | N.S. | Lu et al. (2006) | |
49 | 77.1 | <0.001 | Ford et al. (2014) | |
Sensation incomplete evacuation | 31 | 38 | 0.045 | Zhao et al. (2011) |
72.1 | 64.8 | N.S. | Lu et al. (2006) | |
44.3 | 70.9 | <0.001 | Ford et al. (2014) | |
Lumpy/hard stool | 70 | 65 | N.S. | Zhao et al. (2011) |
38.4 | 63 | <0.001 | Lu et al. (2006) | |
45.5 | 81.7 | <0.001 | Ford et al. (2014) | |
Sensation of anorectal blockage | 46 | 43 | N.S. | Zhao et al. (2011) |
53.5 | 46.3 | N.S. | Lu et al. (2006) | |
31.2 | 56 | <0.001 | Ford et al. (2014) | |
Infrequent defecations | 56 | 57 | N.S. | Zhao et al. (2011) |
26.2 | 42.6 | 0.03 | Lu et al. (2006) | |
25.7 | 53.1 | <0.001 | Ford et al. (2014) | |
Manual maneuver | 10 | 10 | N.S. | Zhao et al. (2011) |
16.3 | 11.1 | N.S. | Lu et al. (2006) | |
14.3 | 32.6 | <0.001 | Ford et al. (2014) |
Discussion
Reference/ Country | Sample /Age | Settings | Study design | Sampling | Sample size (response rate) | Diagnostic criteria |
---|---|---|---|---|---|---|
Neri et al. (2016), Italy | Chronic constipation patient, mean age 50.1 (SD, 16.7) | 39 Italian referral centers for gastrointestinal disorders | Cross-sectional | Purposive | 2203 | Rome III |
Enck et al. (2016), German | Household adults, mean age 51.3 (SD, 0.6) | Telephone registry | Cross-sectional | RLD | 589 (56.8%) | Rome III |
Neri et al. (2014), Italy | Chronic constipation patient, mean age 50.3 (SD: 16.6) | 39 Italian referral centers for gastrointestinal disorders | Cross-sectional | Purposive | 856 | Rome III |
Ford et al. (2014), Canada | Referral patients, ≥16 years old | 2 GI outpatient clinics of two hospitals | Cross-sectional | Purposive | 3656 (86.6%) 343 FC 175 IBS-C | Rome III |
Bellini et al. (2013), Italy | Chronic constipation patient, ≥18 years old | Primary care settings in Province Pisa represented by 41 GPs. | Cross-sectional | Stratified cluster | 229 147 FC 50 IBS-C 32 SPC | Rome III |
Johanson & Kralstein (2007), USA | Adults, ≥18 years old | Membership in the Knowledge Networks Panel | Cross-sectional | Purposive | 557 | Rome II |
Pare et al. (2001), Canada | Household members, ≥18 years old | 5 regions | Cross-sectional | Stratified random | 1149 (57%) | Rome II |
Symptom | Rank 1st | Rank 2nd | Rank 3rd | Rank 4th | Rank 5th | Rank 6th |
---|---|---|---|---|---|---|
Straining | 82.3% [68] |
77.1% [40] | 41.9% [69] | |||
79.0% [36] |
88.0% [42] | |||||
82.2% [70] | ||||||
81.0% [71] | ||||||
49.0% [40] | ||||||
81.6% [42] | ||||||
Sensation incomplete evacuation | 74.2% [69] | 68% [42] | 72.8% [68] | 54.0% [36] | ||
73.8% [70] |
80.0% [42] | |||||
54.2% [71] | ||||||
44.3% [40] | ||||||
70.9% [40] | ||||||
Lumpy/hard stool |
81.7% [40] | 74.4% [68] | 61.9% [42] | 33.2% [69] | ||
100.0% [42] | 71.0% [36] | |||||
74.8% [70] | ||||||
71.5% [71] | ||||||
45.5% [40] | ||||||
Sensation of anorectal blockage | 53.9% [69] | 38.8% [71] | 40.4% [68] |
30.0% [42] | ||
31.2% [40] | 40.4% [70] | |||||
56.0% [40] | 10.9% [42] | |||||
Infrequent defecation |
100.0% [42] | 57.0% [36] | 68.2% [68] | 35.6% [71] | 21.4% [69] | |
68.0% [42] | 64.3% [70] | 25.7% [40] | ||||
53.1% [40] | ||||||
Manual maneuver | 40.7% [69] |
36.0% [42] | 24.5% [68] | |||
24.6% [70] | ||||||
28.4% [71] | ||||||
10.2% [42] | ||||||
14.3% [40] | ||||||
32.6% [40] |