Table 3

Comparing the new strategies from 15 randomly sampled journals (R15) and from 2 top-yielding journals (T2) with the existing search strategies (ES) in the original large journal database

Ovid search strategy*

Sensitivity (%) (95% CI)
Specificity (%) (CI)
Precision (%) (CI)
Accuracy (%) (CI)

High sensitivity
ES: clinical trial.mp, pt. OR random:.mp. OR tu.xs.
99.2 (98.7, 99.8)
70.4 (69.8, 70.9)
9.9 (9.3, 10.5)
71.3 (70.8, 71.8)

R15: clinical trial.mp, pt. OR random:.mp. OR between group:.tw.
98.5 (97.7, 99.3)
76.3‡ (75.8, 76.8)
11.9‡ (11.2, 12.7)
77.0‡ (76.5, 77.4)

T2: clinical trial.mp, pt. OR exp longitudinal studies.
96.8† (95.6, 97.9)
84.1‡ (83.7, 84.6)
16.6‡ (15.6, 17.6)
84.5‡ (84.1, 84.9)

High specificity
ES: randomized controlled trial.mp, pt.
93.1 (91.5, 94.8)
97.5 (97.3, 97.6)
54.4 (52.0, 56.8)
97.3 (97.1, 97.5)

R15: double-blind.mp. OR random: assigned.tw.
47.1† (43.9, 50.3)
98.8‡ (98.7, 99.0)
57.0 (53.5, 60.5)
97.2 (97.0, 97.4)

T2: double-blind:.mp. OR random: assigned.tw.
53.4† (50.2, 56.7)
98.4‡ (98.3, 98.6)
52.7 (49.5, 55.8)
97.0† (96.8, 97.2)

Balanced combination of sensitivity
ES: randomized controlled trial.pt. OR randomized.mp. OR placebo.mp.
95.8 (94.5, 97.1)
95.0 (94.8, 95.3)
38.5 (36.5, 40.5)
95.0 (94.8, 95.3)

R15: randomized controlled trial.pt. OR random: assigned.tw. OR exp research design.
95.2 (93.8, 96.5)
94.6† (94.3, 94.8)
36.3 (34.4, 38.2)
94.6† (94.3, 94.8)

T2: randomized controlled trial.mp, pt. OR random: assigned.tw. OR blind:.mp.
95.4 (94.0, 96.7)
96.1‡ (95.9, 96.3)
44.3‡ (42.2, 46.5)
96.1‡ (95.8,96.3)

*mp = multiple postings, search term appears in title, abstract or subject heading; pt = publication type; : = truncation; tu = therapeutic use subheading; xs = exploded subheading; tw = textword; exp = explosion.

† Statistically significant difference (p-value < 0.05) in favor of the existing search strategy.

‡ Statistically significant difference (p-value < 0.05) in favor of the new search strategy.

Yao et al. BMC Medical Informatics and Decision Making 2008 8:43   doi:10.1186/1472-6947-8-43