Table 3.
Summary data for secondary outcome measures at follow-ups of 4 months and 12 months
|
All participants |
Low–risk participants |
Medium–risk participants |
High–risk participants |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Intervention group (n=568) | Control group (n=283) | Point estimate (95% CI) | p value | Intervention group (n=148) | Control group (n=73) | Point estimate (95% CI) | p value | Intervention group (n=263) | Control group (n=131) | Point estimate (95% CI) | p value | Intervention group (n=157) | Control group (n=79) | Point estimate (95% CI) | p value | |||
| Back pain intensity | ||||||||||||||||||
| 4 months, mean change (SD) | 3·2 (2·5) | 2·6(2·4) | 0·55* (0·23 to 0·86) | 0·0005 | 1·7 (2·2) | 1·5(2·1) | 0·28* (−0·29 to 0·84) | 0·3182 | 3·5 (2·6) | 2·8(2·1) | 0·58* (0·06 to 1·10) | 0·0200 | 4·2 (2·3) | 3·4(2·9) | 0·73* (0·04 to 1·42) | 0·0316 | ||
| 12 months, mean change (SD) | 3·0 (2·8) | 2·8(2·6) | 0·11* (−0·21 to 0·43) | 0·5002 | 1·7 (2·3) | 1·7(2·4) | 0·10* (−0·51 to 0·70) | 0·7461 | 3·3 (2·6) | 3·0(2·8) | 0·16* (−0·44 to 0·76) | 0·5802 | 3·7 (2·7) | 3·6(3·2) | −0·01* (−0·72 to 0·70) | 0·9755 | ||
| STarT Back risk group | ||||||||||||||||||
| 4 months | .. | .. | 2·09† (1·40 to 3·12) | 0·0003 | .. | .. | 1·16† (0·36 to 3·67) | 0·8021 | .. | .. | 1·70† (0·95 to 3·03) | 0·0678 | .. | .. | 3·14† (1·63 to 6·06) | 0·0006 | ||
| Low risk | 439 (77%) | 186 (66%) | .. | .. | 134 (91%) | 65 (89%) | .. | .. | 201 (76%) | 89 (68%) | .. | .. | 104 (66%) | 32 (41%) | .. | .. | ||
| Medium risk | 103 (18%) | 70(25%) | .. | .. | 12 (8%) | 7(10%) | .. | .. | 55 (21%) | 36(27%) | .. | .. | 36 (23%) | 27(34%) | .. | .. | ||
| High risk | 26 (5%) | 27(10%) | .. | .. | 2 (1%) | 1(1%) | .. | .. | 7 (3%) | 6(5%) | .. | .. | 17 (11%) | 20(25%) | .. | .. | ||
| 12 months | .. | .. | 1·51† (1·01 to 2·25) | 0·0405 | .. | .. | 0·91† (0·31 to 2·65) | 0·8562 | .. | .. | 1·51† (0·85 to 2·66) | 0·1525 | .. | .. | 1·62† (0·82 to 3·23) | 0·1566 | ||
| Low risk | 430 (76%) | 195 (69%) | .. | .. | 131 (89%) | 65 (89%) | .. | .. | 204 (78%) | 94 (72%) | .. | .. | 95 (61%) | 36 (46%) | .. | .. | ||
| Medium risk | 111 (20%) | 71 (25%) | .. | .. | 17 (11%) | 7(10%) | .. | .. | 56 (21%) | 35(27%) | .. | .. | 38 (24%) | 29(37%) | .. | .. | ||
| High risk | 27 (5%) | 17(6%) | .. | .. | 0 | 1(1%) | .. | .. | 3 (1%) | 2(2%) | .. | .. | 24 (15%) | 14(18%) | .. | .. | ||
| Global change | ||||||||||||||||||
| 4 months | .. | .. | 1·55† (1·16 to 2·07) | 0·0032 | .. | .. | 1·45† (0·80 to 2·60) | 0·2153 | .. | .. | 1·57† (1·04 to 2·36) | 0·0304 | .. | .. | 1·70† (0·98 to 2·96) | 0·0595 | ||
| Much better | 252 (44%) | 99(35%) | .. | .. | 70 (47%) | 28(38%) | .. | .. | 125 (48%) | 50(38%) | .. | .. | 57 (36%) | 21(27%) | .. | .. | ||
| Better | 151 (27%) | 82(29%) | .. | .. | 38 (26%) | 23(32%) | .. | .. | 70 (27%) | 40(31%) | .. | .. | 43 (27%) | 19(24%) | .. | .. | ||
| Not better | 165 (29%) | 102(36%) | .. | .. | 40 (27%) | 22(30%) | .. | .. | 68 (26%) | 41(31%) | .. | .. | 57 (36%) | 39(49%) | .. | .. | ||
| 12 months | .. | .. | 1·23† (0·95 to 1·60) | 0·1104 | .. | .. | 0·80† (0·41 to 1·54) | 0·4812 | .. | .. | 1·54† (0·99 to 2·39) | 0·0520 | .. | .. | 1·26† (0·72 to 2·21) | 0·4072 | ||
| Much better | 229 (40%) | 99(35%) | .. | .. | 57 (39%) | 32(44%) | .. | .. | 116 (44%) | 46(35%) | .. | .. | 56 (36%) | 21(27%) | .. | .. | ||
| Better | 121 (21%) | 63(22%) | .. | .. | 36 (24%) | 17(23%) | .. | .. | 59 (22%) | 31(24%) | .. | .. | 26 (17%) | 15(19%) | .. | .. | ||
| Not better | 218 (38%) | 121(43%) | .. | .. | 55 (37%) | 24(33%) | .. | .. | 88 (33%) | 54(41%) | .. | .. | 75 (48%) | 43(54%) | .. | .. | ||
| PCS–catastrophising | ||||||||||||||||||
| 4 months, mean change (SD) | 6·4 (10·8) | 3·9(10·4) | 2·35* (0·91 to 3·79) | 0·0010 | 2·6 (7·3) | 1·3(8·0) | 1·10* (−0·82 to 3·02) | 0·2590 | 5·9 (10·1) | 3·6(10·1) | 1·88* (−0·09 to 3·84) | 0·0531 | 10·8 (12·1) | 6·9(13·3) | 3·91* (0·41 to 7·41) | 0·0242 | ||
| 12 months, mean change (SD) | 6·1 (10·6) | 4·4(11·4) | 1·69* (0·37 to 3·01) | 0·0113 | 3·2 (8·6) | 1·6(7·7) | 1·47* (−0·60 to 3·54) | 0·1516 | 5·7 (9·0) | 3·6(10·5) | 1·74* (−0·11 to 3·60) | 0·0630 | 9·4 (12·1) | 8·1(12·7) | 1·35* (−1·70 to 4·40) | 0·3816 | ||
| TSK–fear avoidance | ||||||||||||||||||
| 4 months, mean change (SD) | 5·5 (7·0) | 3·2(6·0) | 2·52* (1·61 to 3·43) | <0·0001 | 3·5 (7·1) | 2·8(7·3) | 0·86* (−1·01 to 2·73) | 0·3540 | 5·2 (7·9) | 2·8(5·7) | 2·72* (1·45 to 3·98) | <0·0001 | 7·9 (8·0) | 4·3(6·0) | 3·70* (1·70 to 5·70) | 0·0003 | ||
| 12 months, mean change (SD) | 5·2 (7·3) | 3·3(10·3) | 2·18* (0·73 to 3·63) | 0·0013 | 3·5 (7·2) | 2·4(9·3) | 1·22* (−1·26 to 3·70) | 0·3030 | 4·9 (7·6) | 3·2(8·2) | 2·14* (0·23 to 4·04) | 0·0181 | 7·3 (7·7) | 4·3(7·2) | 3·12* (1·18 to 5·06) | 0·0016 | ||
| HADS, anxiety subscale | ||||||||||||||||||
| 4 months, mean change (SD) | 1·7 (3·6) | 1·2(4·0) | 0·63* (0·08 to 1·18) | 0·0208 | 0·6 (3·3) | 0·9(3·5) | −0·17* (−0·97 to 0·62) | 0·6666 | 1·7 (3·8) | 0·8(3·7) | 1·10* (0·33 to 1·86) | 0·0039 | 2·8 (4·3) | 2·2(4·5) | 0·56* (−0·57 to 1·69) | 0·3155 | ||
| 12 months, mean change (SD) | 1·3 (3·9) | 1·0(4·4) | 0·45* (−0·10 to 1·01) | 0·1035 | 0·5 (3·2) | 0·8(4·0) | −0·13* (−1·22 to 0·96) | 0·8023 | 1·3 (4·2) | 0·6(4·2) | 0·88* (0·08 to 1·68) | 0·0283 | 2·1 (4·5) | 1·7(5·0) | 0·28* (−1·14 to 1·71) | 0·6783 | ||
| HADS, depression subscale | ||||||||||||||||||
| 4 months, mean change (SD) | 1·7 (3·7) | 1·1(3·3) | 0·71* (0·26 to 1·15) | 0·0018 | 0·3 (3·2) | 0·2(3·3) | 0·09* (−0·69 to 0·88) | 0·8086 | 1·7 (3·6) | 1·2(3·5) | 0·79* (0·13 to 1·45) | 0·0193 | 3·0 (4·3) | 1·9(3·8) | 1·13* (0·16 to 2·09) | 0·0223 | ||
| 12 months, mean change (SD) | 1·4 (4·1) | 0·9(4·0) | 0·62* (0·07 to 1·17) | 0·0227 | 0·2 (3·3) | 0·2(3·5) | −0·03* (−0·92 to 0·86) | 0·9494 | 1·3 (3·7) | 1·0(3·8) | 0·63* (−0·10 to 1·36) | 0·0863 | 2·7 (4·7) | 1·5(4·5) | 1·21* (0·02 to 2·40) | 0·0413 | ||
| SF12, physical component | ||||||||||||||||||
| 4 months, mean change (SD) | −7·5 (13·0) | −5·2(13·3) | −2·83* (−4·62 to −1·05) | 0·0010 | −3·2 (9·6) | −1·8(9·7) | −1·50* (−3·89 to 0·89) | 0·2137 | −9·1 (11·7) | −6·4(10·7) | −3·27* (−5·51 to −1·03) | 0·0037 | −8·9 (15·1) | −6·4(15·8) | −3·13* (−7·50 to 1·23) | 0·1215 | ||
| 12 months, mean change (SD) | −7·5 (11·3) | −5·2(10·9) | −2·93* (−4·31 to −1·56) | <0·0001 | −4·0 (9·7) | −2·4(10·1) | −1·70* (−4·25 to 0·85) | 0·1825 | −8·8 (11·5) | −5·7(11·7) | −3·74* (−6·02 to −1·46) | 0·0012 | −8·6 (12·2) | −6·8(13·1) | −2·46* (−5·90 to 0·97) | 0·1464 | ||
| SF12, mental component | ||||||||||||||||||
| 4 months, mean change (SD) | −2·1 (11·3) | −2·1(11·0) | −0·16* (−1·63 to 1·32) | 0·8327 | 0·5 (12·4) | −1·0(10·2) | 0·96* (−1·68 to 3·60) | 0·4640 | −1·5 (10·4) | −1·1(12·0) | −0·80* (−2·92 to 1·31) | 0·4497 | −5·5 (12·5) | −4·8(14·3) | −0·27* (−3·98 to 3·45) | 0·8811 | ||
| 12 months, mean change (SD) | −1·7 (13·0) | −1·2(13·4) | −0·69* (−2·39 to 1·01) | 0·4050 | 1·3 (10·7) | −0·4(9·9) | 1·18* (−1·12 to 3·49) | 0·3124 | −1·2 (12·3) | −0·1(12·7) | −1·53* (−3·62 to 0·55) | 0·1468 | −5·5 (13·8) | −3·6(13·8) | −1·31* (−5·04 to 2·43) | 0·4682 | ||
| Work loss‡ | ||||||||||||||||||
| Days off work, mean (SD) | 4·4 (21·2) | 12·2(35·1) | 2·76§ (2·52 to 3·01) | <0·0001 | 0·4 (1·2) | 3·0(11·9) | 7·06§ (4·28 to 11·6) | <0·0001 | 4·1 (15·8) | 18·4(47·2) | 5·17§ (4·52 to 5·92) | <0·0001 | 9·9 (35·4) | 10·6(18·2) | 1·46§ (1·24 to 1·72) | <0·0001 | ||
| Satisfaction with care¶ | .. | .. | 1·98† (1·45 to 2·70) | <0·0001 | .. | .. | 1·24† (0·68 to 2·25) | 0·4784 | .. | .. | 2·15† (1·35 to 3·40) | 0·0013 | .. | .. | 3·18† (1·68 to 6·00) | 0·0005 | ||
| Very satisfied | 166/416 (40%) | 46/197(23%) | .. | .. | 30/106 (28%) | 14/56(25%) | .. | .. | 87/197 (44%) | 22/91(24%) | .. | .. | 49/113 (43%) | 10/50(20%) | .. | .. | ||
| Quite satisfied' | 139/416 (33%) | 81/197(41%) | .. | .. | 33/106 (31%) | 21/56(38%) | .. | .. | 63/197 (32%) | 39/91(43%) | .. | .. | 43/113 (38%) | 21/50(42%) | .. | .. | ||
| Not satisfied | 111/416 (27%) | 70/197(36%) | .. | .. | 43/106 (41%) | 21/56(38%) | .. | .. | 47/197 (24%) | 30/91(33%) | .. | .. | 21/113 (19%) | 19/50(38%) | .. | .. | ||
Data are number (%), unless otherwise indicated. PCS=Pain Catastrophizing Scale. TSK=Tampa Scale of Kinesiophobia. HADS=Hospital Anxiety and Depression Scale. SF12=Short Form 12. RMDQ=Roland and Morris Disability Questionnaire.
*
Mean difference—ie, mean for the intervention group minus mean for the control group (by use of linear regression adjusted for age, sex, baseline score, baseline RMDQ, and duration of back pain).
†
Odds ratio represents the proportional odds in terms of ordered response categories for the intervention group relative to the control group (by use of ordinal logistic regression adjusted for age, sex, baseline RMDQ, and duration of back pain).
‡
Analysis of time off work (days) is based on a total subsample of 298 of 567 responders who reported being currently employed at 12 months follow-up, and relates to leave due to low back pain during the period between baseline and follow-up at 12 months.
§
Incidence rate ratio for the extra work days lost in the control group relative to the intervention group (by use of Poisson regression adjusted for age, sex, baseline RMDQ, and duration of back pain).
¶
Analysis was based on 613 responders to the question about satisfaction with care at 4 months follow-up: 416 in the intervention group and 197 in the control group.