tetano
Editor, Senior Moderator
J Clin Epidemiol. 2014 Apr 23. pii: S0895-4356(14)00060-2. doi: 10.1016/j.jclinepi.2014.02.009. [Epub ahead of print]
After adjusting for bias in meta-analysis seasonal influenza vaccine remains effective in community-dwelling elderly.
Darvishian M1, Gefenaite G1, Turner RM2, Pechlivanoglou P3, Van der Hoek W4, Van den Heuvel ER5, Hak E6.
Author information
Abstract
OBJECTIVE:
To compare the performance of the bias-adjusted meta-analysis to the conventional meta-analysis assessing seasonal influenza vaccine effectiveness among community-dwelling elderly aged 60 years and older.
STUDY DESIGN AND SETTING:
Systematic literature search revealed 14 cohort studies that met inclusion and exclusion criteria. Laboratory-confirmed influenza, influenza-like illness, hospitalization from influenza and/or pneumonia, and all-cause mortality were study outcomes. Potential biases were identified using bias checklists. The magnitude and uncertainty of biases were assessed by expert opinion. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using random effects model.
RESULTS:
After incorporating biases, overall effect estimates regressed slightly toward no effect, with the largest relative difference between conventional and bias-adjusted ORs for laboratory-confirmed influenza (OR, 0.18; 95% CI: 0.01, 3.00 vs. OR, 0.23; 95% CI: 0.03, 2.04). In most of the studies, CIs widened reflecting uncertainties about the biases. The between-study heterogeneity reduced considerably with the largest reduction for all-cause mortality (I2 = 4%, P = 0.39 vs. I2 = 91%, P < 0.01).
CONCLUSION:
This case study showed that after addressing potential biases influenza vaccine was still estimated effective in preventing hospitalization from influenza and/or pneumonia and all-cause mortality. Increasing the number of assessors and incorporating empirical evidence might improve the new bias-adjustment method.
Copyright ? 2014 The Authors. Published by Elsevier Inc. All rights reserved.
KEYWORDS:
Bias adjustment, Community-dwelling elderly, Meta-analysis, Observational studies, Seasonal influenza, Vaccination
PMID:
24768004
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24768004
After adjusting for bias in meta-analysis seasonal influenza vaccine remains effective in community-dwelling elderly.
Darvishian M1, Gefenaite G1, Turner RM2, Pechlivanoglou P3, Van der Hoek W4, Van den Heuvel ER5, Hak E6.
Author information
Abstract
OBJECTIVE:
To compare the performance of the bias-adjusted meta-analysis to the conventional meta-analysis assessing seasonal influenza vaccine effectiveness among community-dwelling elderly aged 60 years and older.
STUDY DESIGN AND SETTING:
Systematic literature search revealed 14 cohort studies that met inclusion and exclusion criteria. Laboratory-confirmed influenza, influenza-like illness, hospitalization from influenza and/or pneumonia, and all-cause mortality were study outcomes. Potential biases were identified using bias checklists. The magnitude and uncertainty of biases were assessed by expert opinion. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using random effects model.
RESULTS:
After incorporating biases, overall effect estimates regressed slightly toward no effect, with the largest relative difference between conventional and bias-adjusted ORs for laboratory-confirmed influenza (OR, 0.18; 95% CI: 0.01, 3.00 vs. OR, 0.23; 95% CI: 0.03, 2.04). In most of the studies, CIs widened reflecting uncertainties about the biases. The between-study heterogeneity reduced considerably with the largest reduction for all-cause mortality (I2 = 4%, P = 0.39 vs. I2 = 91%, P < 0.01).
CONCLUSION:
This case study showed that after addressing potential biases influenza vaccine was still estimated effective in preventing hospitalization from influenza and/or pneumonia and all-cause mortality. Increasing the number of assessors and incorporating empirical evidence might improve the new bias-adjustment method.
Copyright ? 2014 The Authors. Published by Elsevier Inc. All rights reserved.
KEYWORDS:
Bias adjustment, Community-dwelling elderly, Meta-analysis, Observational studies, Seasonal influenza, Vaccination
PMID:
24768004
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24768004