Table 5 Sensitivity, specificity, positive and negative predictive values for the five simple definitions compared to the Rome III criteria and modified Rome III criteria as gold standards
From: Defining constipation to estimate its prevalence in the community: results from a national survey
Gold standard | Simple definition | Sensitivity (95% Confidence interval) | Specificity (95% Confidence interval) | Positive Predictive Value (PPV) (95% Confidence interval) | Negative Predictive Value (NPV) (95% Confidence interval) |
Chronic constipation (Rome III criteria) | Self-reported constipation over past 2 weeks | 64.5% (60.2, 68.7) | 87.7% (85.9, 89.2) | 62.2% (57.9, 66.4) | 88.7% (87.0, 90.2) |
Self-reported constipation over past 3 months | 72.0% (67.8, 75.8) | 84.3% (82.4, 86.1) | 59.2% (55.1, 63.0) | 90.5% (88.9, 91.9) | |
Self-reported constipation over past 12 months | 91.1% (88.8, 93.4) | 51.3% (48.8, 53.8) | 37.1% (34.4, 39.9) | 94.5% (93.1, 96.1) | |
Fewer than 3 bowel motions per week over past 3 months | 46.2% (41.8, 50.6) | 88.8% (87.1, 90.2) | 56.4% (51.5, 61.2) | 84.0% (82.1, 85.7) | |
|  | Fewer than 3 bowel motions per week over past 12 months | 17.3% (14.2, 20.1) | 93.0% (91.7, 94.2) | 44.0% (37.1, 51.1) | 78.1% (76.2, 80.0) |
Sub-chronic constipation (modified Rome III criteria) | Self-reported constipation over past 2 weeks | 50.6% (47.1, 54.0) | 92.0% (90.3, 93.4) | 80.5% (76.8, 83.7) | 39.6% (37.5, 41.7) |
Self-reported constipation over past 3 months | 61.3% (57.9, 64.6) | 91.9% (90.3, 93.3) | 83.2% (80.0, 86.0) | 78.4% (76.2, 80.4) | |
Self-reported constipation over past 12 months | 84.3% (81.6, 86.6) | 57.7% (54.9, 60.5) | 56.6% (53.8, 59.4) | 84.9% (82.3, 87.1) | |
Fewer than 3 bowel motions per week over past 3 months | 42.1% (38.7, 45.5) | 95.1% (93.7, 96.2) | 84.9% (81.0, 88.1) | 71.5% (69.2, 73.6) | |
Fewer than 3 bowel motions per week over past 12 months | 16.9% (14.4, 19.6) | 95.4% (94.1, 96.5) | 70.7% (63.9, 76.7) | 63.7% (61.4, 65.8) |