Table 3. Observed and expected frequency of multiple somatic symptoms and associations with multi-site pain.
| Number of somatic symptoms | Observed number of subjects | Expected number of subjectsa | Ratio of observed to expected | Association with pain at ≥4 vs. 0 anatomical sites | |||||
|---|---|---|---|---|---|---|---|---|---|
| Number with no pain | Number with pain at ≥4 sites | PRRb | (95%CI) | PAFc (%) | (95%CI) | ||||
| 0 | 6,016 | 3,433 | 1.75 | 3,125 | 374 | 1 | |||
| 1 | 2,312 | 4,546 | 0.51 | 779 | 291 | 2.3 | (2.0–2.7) | 8.9 | (6.8–11.0) |
| 2 | 1,551 | 2,817 | 0.55 | 336 | 342 | 4.0 | (3.3–4.8) | 13.7 | (11.5–15.8) |
| 3 | 944 | 1,020 | 0.93 | 149 | 295 | 5.0 | (4.1–6.1) | 12.6 | (10.7–14.6) |
| 4 | 618 | 224.6 | 2.75 | 86 | 226 | 5.1 | (4.1–6.5) | 9.7 | (7.6–11.7) |
| 5 | 326 | 29.26 | 11.1 | 30 | 164 | 5.9 | (4.8–7.4) | 7.3 | (5.5–9.1) |
| 6 | 185 | 2.058 | 89.9 | 14 | 104 | 6.0 | (4.6–7.7) | 4.6 | (3.2–6.0) |
| 7 | 120 | 0.060 | 2000 | 15 | 78 | 5.8 | (4.6–7.2) | 3.4 | (2.2–4.7) |
| ≥1 | 6,056 | 8,639.18 | 0.70 | 1,409 | 1,500 | 3.8 | (3.2–4.5) | 59.0 | (53.5–64.5) |
| ≥3 | 2,193 | 1,276.23 | 1.72 | 294 | 867 | 5.6 | (4.4–7.0) | 37.9 | (30.9–44.9) |
a Expected number given the overall prevalence of each symptom, and assuming no association between the occurrence of one symptom and another after allowance for sex and age (in four 10-year strata)
b Prevalence rate ratio adjusted for sex and age (in four 10-year strata)
c Population attributable fraction