2 research outputs found
Pregnancy as a risk factor for severe influenza infection: an individual participant data meta-analysis
Background: WHO identifies pregnant women to be at increased risk for severe outcomes from influenza virus
infections and recommends that they be prioritized for influenza vaccination. The evidence supporting this,
however, is inconsistent. Ecologic studies in particular suggest more severe outcomes from influenza infection
during pregnancy than studies based on individual patient data. Individual studies however may be underpowered
and, as reported in a previous systematic review, confounding factors could not be adjusted for. We therefore
conducted an individual participant data meta-analysis to assess the risk for severe outcomes of influenza infection
in pregnant women while adjusting for other prognostic factors.
Methods: We contacted authors of studies included in a recently published systematic review. We pooled the
individual participant data of women of reproductive age and laboratory confirmation of influenza virus infection.
We used a generalized linear mixed model and reported odds ratios (OR) and 95% confidence intervals (CI).
Results: A total of 33 datasets with data on 186,656 individuals were available, including 36,498 eligible women of
reproductive age and known pregnancy status. In the multivariable model, pregnancy was associated with a 7
times higher risk of hospital admission (OR 6.80, 95%CI 6.02–7.68), among patients receiving medical care as in- or
outpatients, pregnancy was associated with a lower risk of admission to intensive care units (ICU; OR 0.57, 95%CI
0.48–0.69), and was not significantly associated with death (OR 1.00, 95%CI 0.75–1.34).
Conclusions: Our study found a higher risk of influenza associated hospitalization among pregnant women as
compared to non-pregnant women. We did not find a higher mortality rate or higher likelihood of ICU admission
among pregnant women who sought medical care. However, this study did not address whether a true
community based cohort of pregnant women is at higher risk of influenza associated complications
Pregnancy as a risk factor for severe influenza infection: an individual participant data meta-analysis
Background: WHO identifies pregnant women to be at increased risk for severe outcomes from influenza virus
infections and recommends that they be prioritized for influenza vaccination. The evidence supporting this,
however, is inconsistent. Ecologic studies in particular suggest more severe outcomes from influenza infection
during pregnancy than studies based on individual patient data. Individual studies however may be underpowered
and, as reported in a previous systematic review, confounding factors could not be adjusted for. We therefore
conducted an individual participant data meta-analysis to assess the risk for severe outcomes of influenza infection
in pregnant women while adjusting for other prognostic factors.
Methods: We contacted authors of studies included in a recently published systematic review. We pooled the
individual participant data of women of reproductive age and laboratory confirmation of influenza virus infection.
We used a generalized linear mixed model and reported odds ratios (OR) and 95% confidence intervals (CI).
Results: A total of 33 datasets with data on 186,656 individuals were available, including 36,498 eligible women of
reproductive age and known pregnancy status. In the multivariable model, pregnancy was associated with a 7
times higher risk of hospital admission (OR 6.80, 95%CI 6.02–7.68), among patients receiving medical care as in- or
outpatients, pregnancy was associated with a lower risk of admission to intensive care units (ICU; OR 0.57, 95%CI
0.48–0.69), and was not significantly associated with death (OR 1.00, 95%CI 0.75–1.34).
Conclusions: Our study found a higher risk of influenza associated hospitalization among pregnant women as
compared to non-pregnant women. We did not find a higher mortality rate or higher likelihood of ICU admission
among pregnant women who sought medical care. However, this study did not address whether a true
community based cohort of pregnant women is at higher risk of influenza associated complications