Table 1

Summary of findings: ribavirin vs. no ribavirin for treating patients with CCHF (population: patients with CCHF; settings: hospital based; intervention: ribavirin)

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect (95% CI)

No of Participants (studies)

Quality of Comments

the evidence (GRADE)

Assumed risk

Corresponding risk

Control

ribavirin


Mortality (RCT)

Follow-up: mean 8 weeks

56 per 1000

63 per 1000

(16 to 242)

RR 1.13

(0.29 to 4.32)

136

(1 study)

⊕⊕⊖⊖

low1,2


Mortality (Observational studies)

Follow-up: 1-12 months

254 per 1000

142 per 1000

(89 to 229)

RR 0.56

(0.35 to 0.9)

955

(11 studies)

⊕⊖⊖⊖

Very low3,4,5,6


Length of Hospital stay (RCT)

Days in hospital Follow-up: mean 8 weeks

The mean length of hospital stay (rct) in the control groups was

6.3 days

The mean Length of hospital stay (RCT) in the intervention groups was

0.21 standard deviations lower (0.55 lower to 0.12 higher)

136

(1 study)

⊕⊖⊖⊖

very low1,2


Length of Hospital Stay (Observational studies)

days in hospital Follow-up: mean 4-24 months

The mean length of hospital stay (observational studies) in the control groups was

6.4 days

The mean Length of hospital stay (Observational studies) in the intervention groups was

0.60 standard deviations lower (1.21 lower to 0 higher)

303

(3 studies)

⊕⊖⊖⊖

Very low3,5,6,7


*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.

Assessment notes

1 No details of allocation concealment and method of randomisation was provided. Open label.

2 Wide confidence intervals.

3 Details of study design and population characteristics not provided in most studies.

4 Two studies (Alavi-Naimi 2006 and Nadeen 2003) were significantly more favourable to ribavirin than the other 9 included observational studies.

5 Although there was no significant lateral asymmetry on the funnel plot, and Egger's regression was not significant (intercept: 0.829, 2-tailed p-value = 0.408), we cannot completely discard publication bias because all studies were observational and published onl in Iran, Pakistan and Turkey.

6 Most studies used historical controls and provided little or no information about how patients were selected, whether they represent the whole population in risk or characteristics of included patients.

7 One study (Cevik 2008) was significantly more favourable to ribavirin than the other 2 included observational studies.

Soares-Weiser et al. BMC Infectious Diseases 2010 10:207   doi:10.1186/1471-2334-10-207

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