TABLE 12.
INTERFERON-GAMMA 1B GRADE EVIDENCE PROFILE*
|
Quality Assessment |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of
Studies |
Design |
Limitations |
Inconsistency |
Indirectness |
Imprecision |
Other
Considerations |
|||||||
| Mortality (follow-up 48-96 wk; Study follow up) | 3‡ | Randomized trials | No serious limitations§ | No serious inconsistency | No serious indirectness | No serious imprecision¶ | None | ||||||
| Influenza-like Illness (follow-up 48–96 wk) | 3 | Randomized trials | No serious limitations | No serious inconsistency | No serious indirectness | No serious imprecision | None | ||||||
| Fever (follow-up 48–96 wk) | 3 | Randomized trials | No serious limitations | No serious inconsistency | No serious indirectness | No serious imprecision | None | ||||||
| Fatigue (follow-up 48–96 wk) | 3 | Randomized trials | No serious limitations | No serious inconsistency | No serious indirectness | No serious imprecision | None | ||||||
| Any Adverse
Events (follow-up 48–96 wk) |
3 |
Randomized
trials |
No serious
limitations |
No serious
inconsistency |
No serious
indirectness†† |
No serious
imprecision |
None |
||||||
|
Summary of Findings |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of
Patients |
Effect |
|||||||||
| IFN-γ |
No
IFN-γ |
Relative
(95% CI) |
Absolute |
Quality |
Importance† |
|||||
| Mortality (follow-up 48-96 wk; Study follow up) | 95/722 (13.2%) | 63/452 (13.9%) | RR, 0.94 (0.69–1.28)‖ | 8 fewer per 1,000 (from 43 fewer to 39 more) | ⊕⊕⊕⊕ High | Critical | ||||
| Influenza-like Illness (follow-up 48–96 wk) | 232/713 (32.5%) | 57/443 (12.9%) | RR, 2.31 (1.78–3.01)** | 169 more per 1,000 (from 100 more to 259 more) | ⊕⊕⊕⊕ High | Critical | ||||
| Fever (follow-up 48–96 wk) | 209/713 (29.3%) | 41/443 (9.3%) | RR, 3.22 (2.35–4.41)** | 205 more per 1,000 (from 125 more to 316 more) | ⊕⊕⊕⊕ High | Critical | ||||
| Fatigue (follow-up 48–96 wk) | 221/713 (31%) | 98/443 (22.1%) | RR, 1.35 (1.10–1.67)** | 77 more per 1,000 (from 22 more to 148 more) | ⊕⊕⊕⊕ High | Critical | ||||
| Any Adverse
Events (follow-up 48–96 wk) |
710/722
(98.3%) |
439/452
(97.1%) |
RR, 1.01
(0.99–1.03) |
10 more per
1,000 (from 10 fewer to 29 more) |
⊕⊕⊕⊕ High |
Important |
||||
overall quality of evidence rating is listed in the first row and is the one used in the text of the document. The quality rating for outcomes listed in other rows may differ. How these additional outcomes are rated in terms of quality does not influence the final quality rating as they are to inform, but not to make, decisions.
Importance rating: The relative importance of the outcome for decision making. The rating “critical” indicates making recommendations on choice of testing and treatment strategies. The rating “important” indicates that the outcome is important but not critical for making recommendations.
Studies had different length of follow-up.
In the study by Ziesche and coworkers the methods of randomization, concealment, and other study characteristics were not well described. However, we did not downgrade the quality of evidence, because the results had little impact on the overall results.
The panel did not downgrade for imprecision, although the confidence intervals remain wide despite the two larger studies that have been conducted. One of the underlying reasons for not downgrading is that in the context of the downsides of therapy the still-conceivable benefit (based on the confidence intervals) of therapy likely does not outweigh the harms.
No patient (a total of 18 patients were reported) in the study by Ziesche and colleagues had died after 1 year of follow-up. These data were pooled using a fixed effect model with data from the studies by King and coworkers and by Raghu and colleagues. Ziesche and coworkers reported no death in either group.
The study by Ziesche and colleagues was not included as this outcome was not reported separately.
It is questionable whether counting of any adverse event is direct enough for decision making. It can lead to blurring the effect of important adverse effects.