Table 3

Impact of PE-Dx CDS on usability (mean score (standard deviation), effect size (95% CI) and p value) (n=32)

Dependent variablesMDCalcPE-Dx CDSEffect size (CI)P value
Effectiveness
 % appropriate decision83.75% (134/160)94.38% (151/160)0.35* (0.32 to 0.37)p<0.01
 Confidence level†80.21 (18.94)82.71 (18.21)0.13‡ (−0.05 to 0.31)p=0.14
Efficiency
 Time per scenario (in seconds)117.37 (38.91)95.84 (25.42)−0.55‡ (−0.71 to −0.38)p<0.001
 Number of clicks per scenario16.49 (4.82)17.90 (3.91)0.29‡ (0.09 to 0.48)p<0.01
 Number of scrolls per scenario7.47 (2.92)6.31 (2.50)−0.39‡ (−0.57 to −0.21)p<0.001
 Number of navigation elements per scenario15.53 (5.01)10.23 (2.74)−1.05‡ (−1.26 to −0.83)p<0.001
 Perceived workload¶4.45 (1.53)3.64 (1.78)−0.52‡ (−0.68 to −0.37)p<0.001
Satisfaction§
 CUSQ: overall satisfaction5.62 (0.94)6.18 (0.66)0.58‡ (0.18 to 0.98)p<0.001
 CUSQ: system usefulness5.65 (0.95)6.26 (0.67)0.62‡ (0.19 to 1.05)p<0.01
 CUSQ: information quality5.73 (0.98)6.17 (0.73)0.43‡ (0.03 to 0.83)p<0.05
 CUSQ: interface quality5.48 (1.15)6.02 (0.86)0.45‡ (0.07 to 0.84)p<0.05
  • *Cohen (h) effect size based on the inverse sine of the square root of the proportional values.

  • †One question: 0 (no confidence) to 100 (very high confidence).

  • ‡Becker75 adjusted effect size for repeated measures.

  • §Response categories: 1 (strongly disagree) to 7 (strongly agree).55

  • ¶Scale: 1 (low) to 10 (high).54

  • CUSQ, computer system usability questionnaire; PE-Dx CDS, clinical decision support for pulmonary embolism diagnosis.