Table 1. Characteristics of studies evaluating BMI and persistent pain after surgery in breast cancer patients.
| Author,publication year, location | Study type | Cases/subject or control (age), duration of follow-up | Categoriesof exposure/reference | OR (95% CI) | Matched/adjustedvariables |
|---|---|---|---|---|---|
| WHEL Study | CS | 1664/2066 (26-70), 4 years | BMI:18.5-2525-30≥30BMI:Every unit increaseBMI change:Every unit increaseBMI:<30≥30BMI:<25≥25 | OR1.0 (Ref)1.42 (1.08-1.87)2.51 (1.79-3.58)OR1.07 (1.05-1.10)OR1.10 (1.04-1.16)OR1.0 (Ref)2.22 (1.61-3.12)OR1.0 (Ref)1.80 (1.42-2.29) | radiation, age at diagnosis, baseline pain, baseline BMI |
| Additional studies through literature search | |||||
| Alves Nogueira Fabro, 2012, Brazil, Rio de Janeiro | CS | 88/168 (mean 58), 7.5 months | BMI:<30≥30 | OR1.0 (Ref)0.87 (0.45-1.66) | N/A |
| Lundstedt, 2012, Sweden | CS | 116/873 (28-73), 3-17 years | BMI:<30≥30BMI:<25≥25 | OR1.0 (Ref)0.93 (0.54-1.62)OR1.0 (Ref)1.06 (0.71-1.57) | N/A |
| Shahbazi, 2015, Iran | HC-CS | 61/61 (mean 46-48) | BMI:<30≥30BMI:<25≥25BMI:18.5-2525-30≥30 | OR1.0 (Ref)0.89 (0.35-2.28)OR1.0 (Ref)0.93 (0.44-1.96)OR1.0 (Ref)0.74 (0.298-1.836)0.748 (0.228-2.459) | education, drug intake, infection, pain before surgery, type of breast cancer, stage of cancer, type of surgery, and adjuvant therapy |
| Johannsen, 2015, Denmark (nationwide) | CS | 614/1872 (18-70), 15 months | BMI:<30≥30BMI:<25≥25BMI:18.5-2525-30≥3030-35≥35 | OR1.0 (Ref)1.44 (1.04-2.01)OR1.0 (Ref)1.16 (0.93-1.46)OR1.0 (Ref)0.97 (0.73-1.29)1.46 (1.04-2.06)1.65 (1.14-2.41)0.92 (0.44-1.93) | age, pain at 15 months |
| Juhl, 2016, Denmark, Aarhus | CS | 100/261 (mean 64), 3 years | BMI:<30≥30BMI:<25≥25BMI:18.5-2525-30≥30 | OR1.0 (Ref)1.88 (0.99-3.60)OR1.0 (Ref)1.84 (1.10-3.05)OR1.0 (Ref)1.69 (0.92-3.10)2.13 (1.06-4.27) | radiotherapy, axillary procedure |
| Lash, 2000, US, Boston | CS | 91/244 (55+), 16 months | BMI:<30≥30BMI:<25≥25 | OR1.0 (Ref)1.40 (0.74-2.66)OR1.0 (Ref)0.94 (0.56-1.58) | N/A |
| De Oliveira, 2014, Chicago | CS | 110/300 (mean 53 or 61), 6 months | BMI:Every unit increase | OR1.02 (0.98-1.06) | age, axillary lymph node dissection, radiation |
| Meretoja, 2014, Finland | CS | 563/860 (mean 57), 12 months | BMI:Every unit increase | OR1.04 (1.01-1.08) | chronic preoperative pain, preoperative hormone therapy, axillary operation, lymphovascular invasion in the primary tumor, class of risk, chemotherapy, radiotherapy, worst preoperative pain in the area to be operated, No. of previous operations, histological size of the primary tumor, No. of metastatic lymph nodes, Beck Depression Inventory score, Spielberger Anxiety Questionnaire |
BMI: body mass index; OR: odds ratio; CI: confidence interval; CS: cohort study; Ref: reference; N/A: not available; HC-CS: hospital-based case-control study.