Nineteen RCTs (1053 participants in total) including 11 studies on patients with acute SCI (n=625) and eight on patients with non-acute SCI (n=428).
Pooled effects (number of weeks needed of prophylaxis to prevent one infection) for any drug vs no drug comparisons:
1. Acute asymptomatic.
All (6 studies) 3.7 (95% CI: -0.40, -0.15), Chi-square p-value=0.50 Without one outlier (5 studies) 2.6 (95% CI: -0.58, -0.21), Chi-square p-value=0.85.
2. Acute symptomatic.
All (2 studies) not significant (95% CI: -0.08, 0.02), Chi-square p-value=0.95.
3. Non-acute asymptomatic.
All (6 studies) 16.7 (95% CI: -0.12, -0.00), Chi-square p-value=0.51 Quality score of 3+ (4 studies) not significant (95% CI: -0.20, 0.05), Chi-square p-value=0.25. Quality score of 2- (2 studies) not significant (95% CI: -0.27, 0.24), Chi-square p-value=0.87.
4. Non-acute symptomatic.
All (4 studies) not significant (95% CI: -0.11, 0.04), Chi-square p-value=0.71.
Quality score of 3+(3 studies) not significant (95% CI: -0.16, 0.03), Chi-square p-value=0.77.
Quality score of 2-(1 study) not significant (95% CI: -0.11, 0.13), Chi-square p-value=not applicable.
Pooled effects (number of weeks needed of prophylaxis to prevent one infection) for specific drugs vs instillation methods comparisons:
1. Nitrofurantoin.
Acute asymptomatic (2 studies) 4.5 (95% CI: -0.36, 0.08), Chi-square p-value=0.34.
Acute symptomatic (0 studies).
Non-acute asymptomatic (3 studies) not significant (95% CI: -0.13, 0.01), Chi-square p-value=0.34.
Non-acute symptomatic (1 study) not significant (95% CI: -0.18, 0.12), Chi-square p-value=not applicable.
2. Methenamine.
Acute asymptomatic (2 studies) 1.8 (95% CI: -0.87, 0.22), Chi-square p-value=0.34.
Acute symptomatic (no studies).
Non-acute asymptomatic (2 studies) not significant (95% CI: -0.65, 0.14), Chi-square p-value=0.23.
Non-acute symptomatic (no studies).
3. Trimethoprim+sulfamethoxazole.
Acute asymptomatic (2 studies) not significant (95% CI: -0.03, 0.35), Chi-square p-value=0.97.
Acute symptomatic (2 studies) not significant (95% CI: -0.08, 0.02), Chi-square p-value=0.95.
Non-acute asymptomatic (3 studies) not significant (95% CI: -0.16, 0.17), Chi-square p-value=0.76.
Non-acute symptomatic (2 studies) not significant (95% CI: -0.11, 0.09), Chi-square p-value=0.59.
4. Instillations.
Acute asymptomatic (3 studies) not significant (95% CI: -0.52, 0.10), Chi-square p-value=0.28.
Acute symptomatic (no studies).
Non-acute asymptomatic (no studies).
Non-acute symptomatic (no studies).
Quality of studies:
Quality of the acute patient studies ranged from 1 to 5 points, with only one study scoring 5 points and six of the studies scoring 1 point. Quality of the non-acute patient studies ranged from 0 to 5 points, with one study scoring 5 points, 3 studies scoring 4 points and only one study scoring 0 points.
Publication bias:
The funnel plot does not support a significant bias due to the lack of publication of significant results.