Table 3.

Baseline, standardized mean difference, and percentage improvement values for 1555 patients with fibromyalgia.

Degree of Improvement Compared with Baseline**
Outcome MeasuresStandardized Mean Difference (95% CI)*All Patients, Baseline, N/%None, < 10%, N/%Minimal, 10–29%, N/%Moderate, 30–49%, N/%Substantial, ≥ 50%, N/%
FM severity (0–31)1555/100832/53.5353/22.7212/13.6158/10.2
  MeanNV22.724.319.714.07.6
FM criteria (+)1555/100832/94.5353/82.492/43.4158/5.1
WPI (0–19)NV1555/100806/51.8292/18.8176/11.3281/18.1
  Mean13.615.411.68.63.3
Patient global (0–10)0.03 (−0.02, 0.08)1555/100933/60.0284/18.3164/10.5174/11.2
  Mean5.76.65.64.02.1
Pain (0–10)0.22 (0.16, 0.28)1555/100887/57.0324/20.8151/9.7193/12.4
  Mean6.87.56.34.52.1
Fatigue (0–10)NV1555/100866/55.6384/24.7142/9.1163/10.5
  Mean7.68.27.04.82.3
Sleep disturbance (0–10)0.20 (0.14, 0.25)1489/100836/56.1278/18.7128/8.6247/16.6
  Mean6.87.86.64.71.7
Symptom count (0–37)NV1544/100874/56.2367/23.6169/10.9144/9.3
  Mean16.418.314.710.94.7
Mood (0–10)0.15 (0.10, 0.20)1548/100827/53.2330/21.3196/12.6195/12.5
  Mean4.55.14.03.01.5
HAQ (0–3)0.00 (−0.03, 0.03)1555/100994/63.9289/18.6135/8.7137/8.8
  Mean1.31.61.30.90.3
PCS (0–100)−0.11 (−0.14, −0.07)1555/100975/62.7338/21.7152/9.890/5.8
  Mean29.027.633.334.936.5
MCS (0–100)−0.03 (−0.07, 0.02)1555/100987/63.5289/18.6143/9.2136/8.7
  Mean39.736.843.745.546.1
EQ-5D (0–1)−0.10 (−0.16, −0.05)1208/100821/68.0135/11.220/1.7232/19.2
  Mean0.570.550.620.580.65
  • * Standardized mean difference (effect size) = last observation mean minus first observation mean divided by pooled standard deviation. Positive values represent improvement except for PCS, MCS, and EQ-5D, where negative values represent improvement.

  • ** Degree of improvement = percentage improvement at last observation compared with baseline observation. NV: not valid; HAQ: Health Assessment Questionnaire disability index; PCS and MCS: physical and mental component scores from SF-36 (Short-form 36). WPI: Widespread Pain Index.