Table 3.

Incremental Variance in Low-Value Test Ordering Explained by Patient Centered Communication

Variables, by ModelAdjusted Effect on the Probability of Test Ordering* (95% CI)P ValuePseudo-R2
Base model9.3%
Series 4
    Component 1: patients' experience of illness0.1% (−1.0%, 0.8%).849.3%
    Component 2: psychosocial context0.1% (−0.3%, 0.4%).719.3%
    Component 3: attempt to find common ground0.0% (−0.5%, 0.4%).869.3%
Series 5§
    Total MPCC0.0% (−0.8%, 0.8%).949.3%
  • * Adjusted for the randomized controlled trial intervention.

  • The base model included study arm and standardized patient (patient with back pain requesting magnetic resonance imaging, woman requesting dual-energy x-ray absorptiometry, patient with headache requesting magnetic resonance imaging). Headache was associated with significantly less test ordering than back pain.

  • In series 4, each Measure of Patient-Centered Communication (MPCC) component was included individually in separate models with base model variables.

  • § Series 5 included the total MPCC together with base model variables.

  • CI, confidence interval.