Table 2 General results regarding the minimally important difference (MID) determination (N = 46)
| Â | Number | Percent |
|---|---|---|
Approach used for MID determination | ||
 Distribution-based only | 3 | 6.5 |
 Anchor-based only | 6 | 13.1 |
 Both distribution- and anchor-based | 37 | 80.4 |
Term used to design the MID | ||
 MID, referring to: | 29 | 63 |
  Minimally important difference | 16 | 34.8 |
  Minimal important difference | 13 | 28.2 |
 MCID, referring to: | 19 | 41.3 |
  Minimal clinically important difference | 16 | 34.8 |
  Minimum clinically important difference | 2 | 4.3 |
  Minimal clinical important difference | 1 | 2.2 |
 MIC, referring to: | 1 | 2.2 |
  Minimal important change | 1 | 2.2 |
Number of assessment timepoints | ||
 1 | 2 | 4.4 |
 2 | 31 | 67.4 |
 3 | 6 | 13 |
  ≥ 4 | 7 | 15.2 |
Time interval between the assessment times | ||
 2 days | 1 | 2.2 |
 1 month | 7 | 15.2 |
 3–6 months | 6 | 13 |
 1 year | 2 | 4.4 |
 Based on clinical relevance | 3 | 6.5 |
 Multiple with a maximum interval of 6 months | 14 | 30.4 |
 Multiple with a maximum interval > 1 year | 5 | 10.9 |
 Multiple intervals based on clinical relevance | 2 | 4.4 |
Floor and ceiling effects studied | ||
 Yes | 7 | 15.2 |
  Floor and ceiling effects detected (<  15%) | 2 | 28.6 |
  Floor and ceiling effects no detected (<  15%) | 4 | 57.1 |
  Not reported | 1 | 14.3 |
 No | 39 | 84.8 |
Recommendations for futures studies | ||
 Yes | 16 | 34.8 |
 No | 23 | 50 |
 Unclear | 7 | 15.2 |
Limitations highlighted by authors | ||
 Yes | 42 | 91.3 |
 No | 4 | 8.7 |
Possible risk of bias | ||
 Missing data on the HRQOL/PRO measures | 16 | 40 |
 Bias in the selection of the population | 17 | 42.5 |
 Bias in the statistical analysis | 5 | 10.9 |