Summary of findings for the main comparison. Erythropoietin (subcutaneous or intravenous at varying dosages) compared to placebo for anemia in patients with rheumatoid arthritis.
| Erythropoietin (subcutaneous or intravenous at varying dosages) compared to placebo for anemia in patients with rheumatoid arthritis | ||||||
| Patient or population: anemia in patients with rheumatoid arthritis Settings: outpatient Intervention: erythropoietin (subcutaneous or intravenous at varying dosages) Comparison: placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | Erythropoietin (subcutaneous or intravenous at varying dosages) | |||||
| Health‐related quality of life Follow‐up: 8 to 52 weeks | See comment | See comment | 136 (3 studies1) | ⊕⊝⊝⊝ very low2,3 |
Peeters 1996, with 70 participants followed up during 52 weeks reporting patients' global assessment (VAS score 0 to 10), found statistically significant differences comparing EPO versus placebo (median and interquartile range at 52 weeks: 3.5 (1.0 to 6.0) and 4.5 (2.0 to 7.5) P = 0.027, respectively. Pincus 1990, with 17 participants followed up during 8 weeks, reported no significant differences between groups of patient satisfaction in activities of daily living using the mHAQ5 but data were not provided. Nordström 1997, with 46 participants followed up at 12 weeks, reported no significant difference between groups in Stanford Health Assessment Questionnaire scores, Nottingham Health Profile scores, classification of functional class or joint score index scores. |
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| Hemoglobin (Hb) level at the end of the study Follow‐up: 12 to 52 weeks4 | See comment | 116 (2 studies4) | ⊕⊕⊝⊝ low2 |
Nordström 1997 (46 participants) reported a statistically significant increase in hemoglobin level at 12 weeks in the EPO group compared with placebo group (MD 8.00, 95% CI 7.43 to 8.57 g/l; P = 0.00001) Peeters 1996 (70 participants) reported a statistically significant increase in hemoglobin level at 52 weeks in the EPO group (median 134; interquartile range 110 to 158 g/L) compared with placebo group (median 112; interquartile range 86 to 128 g/L) (P = 0.001). |
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Fatigue Not reported |
See comment | See comment | Not estimable | ‐ | See comment | This outcome was not assessed by any of the trials. |
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Safety (Adverse events including adverse drug reaction) Follow‐up: 8 to 52 weeks |
See comment | See comment | Not estimable | (3 studies1) | ⊕⊝⊝⊝ very low2,3 |
Nordström 1997 found no significant alterations in pulse, blood pressure, platelet counts, albumin, creatinine, alanine aminotransferase, or aspartate aminotransferase values .
Peeters 1996 assessed adverse events and found no significant rise in blood pressure and thromboembolic complications. Pincus 1990 found no adverse reactions. |
| Withdrawals due to adverse events | See comment | See comment | Not estimable | ‐ | See comment | Nordström 1997 reported no serious adverse events causing premature discontinuation. This outcome was not reported by the other two trials (Peeters 1996; Pincus 1990). |
| Withdrawals due to lack of efficacy | See comment | See comment | Not estimable | ‐ | See comment | This outcome was not assessed by any of the trials. |
| Withdrawals due to high blood pressure | See comment | See comment | Not estimable | ‐ | See comment | This outcome was not assessed by any of the trials. |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (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). CI: Confidence interval; RR: Risk ratio; | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1. Nordström 1997, Peeters 1996, Pincus 1990 2. Almost all domains had a high or unclear risk of bias. 3. Small sample size 4. Nordström 1997, Peeters 1996 5. mHAQ: modified Stanford Health Assessment Questionnaire