Table 1

Data used to determine the Reliable Change Index (RCI) for the primary and secondary outcome measures of distress in trials

TrialOutcome measure/sS1rxx*SESdiffRCI
Thompson et al (2010)26PrimarymBDI1512.510.884.336.1312.00
SecondaryPHQ-9167.060.892.343.316.49
Ciechanowski et al (2010)27PrimaryHSCL-20170.590.850.230.320.63
Schröder et al (2014)12PrimaryBDI-I1810.370.863.885.4910.76
Gandy et al (2014)11PrimaryNDDI-E193.590.851.391.963.85
HADS-D294.000.821.702.404.70
SecondaryHADS-A293.760.831.552.194.29
Thompson et al (2015)22PrimarymBDI159.420.883.264.629.05
SecondaryPHQ-9163.630.891.201.703.34
  • The designation of outcome measures as being the primary or secondary outcome measure was taken directly from trial reports, except for Gandy et al (2014)11 (see Outcome assessment section).

  • *Internal consistency for: mBDI,15 PHQ-9,16 HSCL-20,17 BDI-I,18 NDDI-E,19 HADS-D and HADS-A.20

  • †The extent of reliable change in and across the trials was also calculated when participants from the trials who did not have a score indicative of clinically significant depression at baseline were excluded. There were such participants in only the Schröder et al12 (2014) (n=3 intervention and n=5 control participants) and Gandy et al11 (2014) (n=9 intervention and n=9 control participants) trials. The exclusion of these participants meant the individual RCIs for these two trials needed to be recalculated as the SD of the trial samples on the primary outcome measure of interest for the trial changed. The recalculaed RCI was 9.23 for Schröder et al12 (2014) and 2.41 for Gandy et al11 (2014).

  • BDI, Beck Depression Inventory; HADS-A, Hospital Anxiety and Depression Scale–Anxiety subscale; HADS-D, Hospital Anxiety and Depression Scale–Depression subscale; HSCL-20, Hopkins Symptom Checklist-20; mBDI, modified Beck Depression Inventory; NDDI-E, Neurological Disorders Depression Inventory for Epilepsy; PHQ-9, Patient Health Questionnaire-9; rxx, reliability of the scale; S1, SD at pre-treatment; Sdiff, SE of difference; SE, SE of measurement. Individual patient data for the secondary outcome measure NDDI-E within Thompson et al22 (2015) were not made available for analysis.