Validation of the General Health Questionnaire 12 for assessing psychological distress in patients with chronic low back pain.

BACKGROUND: The General Health Questionnaire 12 (GHQ-12) is a short easy-to-use scale to assess psychological distress. The GHQ-12 has not been validated for assessing psychological distress in patients with chronic low back pain (LBP). OBJECTIVE: To investigate the psychometric properties of the GHQ-12 in patients with chronic LBP. METHODS: The study involved a population of patients undergoing functional restoration for chronic LBP. The intraclass coefficient correlation was used for test-retest reliability (good if > 0.7) and the standard error measurement for absolute reliability. Construct validity was assessed with the Spearman correlation coefficient (moderate and high if r⩾ 0.35 and 0.5, respectively) and internal consistency with Cronbach's alpha (suitable if > 0.7). Responsiveness was assessed by the Wilcoxon test and effect size. RESULTS: Four hundred and five patients were included. The intraclass coefficient correlation was 0.73 and standard error measurement 2.49. The GHQ-12 showed high convergence with the Beck Depression Inventory and subscales of the Dallas Pain Questionnaire for anxiety and depression and for sociability. It showed moderate convergence with the Quebec Back Pain Disability Scale and subscales of the Dallas Pain Questionnaire for daily activities and for leisure and occupation. Cronbach's alpha was 0.89. The GHQ-12 score changed after functional restoration. It was lower (better) with than without improvement. CONCLUSIONS: We provide validation of the GHQ-12 for assessing psychological distress in patients with chronic LBP.

Visceral obesity and chronic pain: effect of a 4-week rehabilitation program on adipokines and insulin resistance.

Obesity and chronic pain are two major diseases of the 21th century. Our principal objective was to investigate the effects of a 4-week rehabilitation program on adiponectin and leptin concentrations, and insulin resistance, in patients with abdominal obesity and chronic pain syndrome. Our secondary objectives were to investigate the effects of this program on pain, body mass index (BMI), waist circumference and maximal oxygen consumption (VO2max) and to compare changes in VO2max between patients with or without insulin resistance. Among a consecutive sample of 128 patients with abdominal obesity hospitalized for rehabilitation for a chronic pain syndrome, 111 completed the protocol, which was a 4-week rehabilitation program including 6 hr of rehabilitation per day, 5 days per week, in a referral center of rehabilitation. This prospective cohort study compared clinical (BMI, waist circumference, VO2max, pain) and biological measures (concentrations of adiponectin, leptin and insulin, score of homeostasis model assessment of insulin resistance [HOMA]) before and after the program. Plasma leptin, adiponectin and insulin concentrations (P<0.0001) and score of HOMA (P=0.0002) had decreased significantly by the end of the 4 weeks. Pain, BMI and waist circumference decreased significantly, and VO2max improved significantly (P=0.0001). Patients with insulin resistance had less improvement of their aerobic condition at the end of the 4 weeks (P<0.002). The rehabilitation program decreases the concentration of leptin, and improves insulin sensitivity in patients with chronic pain and visceral obesity. Aerobic recovery was worse for patients with insulin resistance than other patients.