Summary of findings 4. Tramadol alone compared with NSAIDs for osteoarthritis.
| Tramadol alone compared with NSAIDs for osteoarthritis | ||||||
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Patient or population: osteoarthritis Settings: outpatient clinics Intervention: tramadol alone Comparison: NSAIDs | ||||||
| Outcomesa | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk** | Corresponding risk** | |||||
| NSAIDs | Tramadol alone | |||||
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Pain assessed with: self‐report VAS pain intensity (scale 0 to 500 where 0 = no pain) Follow‐up: range 4 weeks to 12 weeks |
The mean pain was 300.8 points | The mean pain in the intervention group was 22 points higher (7 higher to 37 higher)b | — | 952 (3 RCTs) | ⊕⊕⊕⊝ Moderatee |
Mean pain: 4% absolute worsening (95% CI 1% to 7% worsening),b 7% relative worsening (95% CI 2% to 12% worsening),f SMD 0.21 (95% CI 0.07 to 0.36), NNTB 12 (95% CI 7 to 35)g |
| 17 out of 100 improved by 20%c | 5 less out of 100 (8 less to 2 more) in the intervention group improved by 20%c | RR 0.71 (95% CI 0.53 to 0.88)d | ||||
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Physical function assessed with: self‐report questionnaire WOMAC Physical Function (scale 0 to 1700, where 0 = no limitation) Follow‐up: range 4 weeks to 12 weeks |
The mean physical function was 1019 points | The mean physical function in the intervention group was 82 higher (32 higher to 131 higher)b |
— | 952 (3 RCTs) | ⊕⊕⊝⊝ Lowe,h |
Mean physical function: 5% absolute worsening (95% CI 2% to 8% worsening),b 8% relative worsening (95% CI 3% to 13% worsening),f SMD 0.23 (95% CI 0.09 to 0.37), NNTB 11 (95% CI 7 to 27)g |
| 17 out of 100 improved by 20%c | 5 less out of 100 (7 less to 2 less) in the intervention group improved by 20%c | RR 0.71 (95% CI 0.59 to 0.88)d | ||||
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Number of participants experiencing any adverse event Follow‐up: 8 weeks |
591 per 1000 | 774 per 1000 (609 to 987) | RR 1.31 (95% CI 1.03 to 1.67) | 128 (3 RCTs) | ⊕⊕⊕⊝ Moderatee |
18% absolute worsening (95% CI 2% more to 40% more), 31% relative worsening (95% CI 3% more to 67% more), NNTH 6 (95% CI 3 to 57) |
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Number of participants who withdrew due to adverse events Follow‐up: range 8 weeks to 12 weeks |
112 per 1000 | 210 per 1000 (142 to 309) | RR 1.88 (95% CI 1.27 to 2.76) | 929 (2 RCTs) | ⊕⊕⊝⊝ Lowe,h | 10% absolute worsening (95% CI 3% more to 20% more), 88% relative worsening (95% CI 27% more to 176% more), NNTH 10 (95% CI 5 to 33) |
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Number of participants experiencing any serious adverse events Follow‐up: range 4 weeks to 8 weeks |
21 per 1000 | 4 per 1000 (0 to 90) | RR 0.21 (95% CI 0.01 to 4.34) | 188 (2 RCTs) | ⊕⊝⊝⊝ Very lowe,i | NNTH not applicable |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
**The assumed and the corresponded risk was calculated from the SMD and SE. CI: confidence interval; MCID: minimal clinically important difference; NNTB: number needed to treat for an additional beneficial outcome; NNTH: number needed to treat for an additional harmful outcome;RR: risk ratio;SD: standard deviation; SE: standard error; SMD: standardized mean difference WOMAC: Western Ontario and McMaster Universities Arthritis Index. | ||||||
| GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aContinuous outcomes summarized using SMD and SE, and binary outcomes expressed as RR. We used standard inverse‐variance fixed‐effect meta‐analysis to combine the trials in Review Manager 5 (Review Manager 2014). bAbsolute effect on a common scale (e.g. 100‐mm, 1700‐point scale) calculated by multiplying the SMD by the SD of the scale (in the control group at baseline) as suggested by the Cochrane Handbook for Systematic Reviews of Interventions (Section 12.6.4; Higgins 2011). cAssumed and corresponding risks calculated from the SMD and SE, with improvement based on an MCID of 20% of the given scale using the Wells calculator (from the Cochrane Musculoskeletal Group Editorial office; musculoskeletal.cochrane.org/). dRR and its 95% CI calculated using the assumed risk of the control group and corresponding risk of the treatment group. The corresponding risk was divided by the assumed risk. eDowngraded one level for unclear risk of bias (all trials had high or unclear risk of at least one type of bias). fRelative improvement percentage defined as relative to the control group risk at baseline. gNNTB corresponded to the number of participants that needed to be treated to see one participant improve. Improvement defined as reaching an MCID of 20% on the given scale. NNTB calculated using the Wells calculator (from the Cochrane Musculoskeletal Group Editorial office; musculoskeletal.cochrane.org/ne.org/). hDowngraded one level for inconsistency. iDowngraded two levels for serious imprecision (few events and wide CI).