Distribution and predictive value of side difference in extension in patients with unilateral problems (n=163). Patients with bilateral pain or increased ESR are excluded
| Side difference in ultrasonic distance | Total | ||||
|---|---|---|---|---|---|
| Absent | Present | ||||
| Side difference in extension | Absent | 120 | 29 | 149 | |
| Present | 4 | 10 | 14 | ||
| Total | 124 | 39 | 163 | ||
Values are number of patients. Pre-test probability of hip effusion = 24%. Predictive value of negative test: 80% (95% CI = 0.79;0.86). Predictive value of positive test: (post-test probability) 71% (95% CI = 0.44;0.98). Likelihood ratio = 7.9.