Improving methods for using patient-centred data for clinical purposes

When patients and doctors are choosing among treatments, one aspect they consider is the patient’s perceptions of change. The “minimal important difference” (MID) is the smallest gain in health where the patient is going to report the intervention was effective. To estimate a treatment’s MID, we measure, from each patient:

• Their “Patient reported outcome” (e.g., health, quality of life) before the treatment
• The same “patient reported outcome” after treatment
• How the patient feels about the change in their “outcome” (e.g., health, quality of life; e.g., much worse, a little worse, the same/no change, a little better, much better)

When choosing among treatments, or choosing whether to continue with or stop taking a treatment, patients and their doctors may consider the MID as an important threshold to experience important in health-related quality of life. Researchers also use the MID to evaluate the effectiveness of interventions.

The MID is a single value and does not differ by the characteristics of the patient. This study sought to measure where people with different demographics (i.e., age, sex, health status) would have different MID values.

We studied two treatments for which patient-reported outcome data was available: gallbladder removal (“Laparoscopic cholecystectomy”), and ankle replacement (“arthrodesis”).