Statins and associated risk of pneumonia: A systematic review and meta-analysis of observational studies

Chun Shing Kwok, Jessica Ka Yan Yeong, Richard M. Turner, Rodrigo Cavallazzi, Sonal Singh, Yoon Kong Loke

Research output: Contribution to journalArticle

Abstract

Purpose: Statins have potential anti-inflammatory effects, but the association between statin use and lower incidence of pneumonia is unclear. We have therefore performed a systematic review on the risk of pneumonia in statin users versus non-users. Methods: MEDLINE and EMBASE were searched in December 2010 for controlled observational studies that reported on the risk of pneumonia in statin users. We performed a random effects meta-analysis and assessed heterogeneity using the I 2 statistic. Results: A total of 451 citations were screened, and ultimately nine studies (4 case-control, 4 retrospective cohort, 1 prospective cohort) with more than 3 million participants were included in the meta-analysis. Pooled analysis of seven studies that reported unadjusted data failed to show a significantly reduced risk of pneumonia [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.84-1.06, p=0.33, I 2=79%] in statin users as compared to nonusers. However, a significant reduction in the likelihood of pneumonia associated with statin use (n=8 studies, OR 0.85, 95% CI 0.75-0.97, p=0.02, I 2=81%) was found in the meta-analysis of adjusted data. Both analyses were limited by substantial statistical heterogeneity. Sensitivity analysis failed to fully clarify the source of heterogeneity, but cohort studies seemed to be less heterogenous (n=5 studies, OR 0.92, 95% CI 0.84-1.01, I 2=43%). Conclusion: Our findings indicate that the purported benefit of statins in preventing pneumonia is inconsistent, and of low magnitude, with upper bounds of the confidence interval being close to null. In view of the substantial statistical and clinical heterogeneity in the dataset, there is no convincing evidence to support the therapeutic application of statins for reducing the risk of pneumonia.

Original languageEnglish (US)
Pages (from-to)747-755
Number of pages9
JournalEuropean Journal of Clinical Pharmacology
Volume68
Issue number5
DOIs
StatePublished - May 2012

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Hydroxymethylglutaryl-CoA Reductase Inhibitors
Observational Studies
Meta-Analysis
Pneumonia
Confidence Intervals
Odds Ratio
MEDLINE
Case-Control Studies
Cohort Studies
Anti-Inflammatory Agents
Incidence

Keywords

  • Meta-analysis
  • Pneumonia
  • Statins

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Pharmacology

Cite this

Statins and associated risk of pneumonia : A systematic review and meta-analysis of observational studies. / Kwok, Chun Shing; Yeong, Jessica Ka Yan; Turner, Richard M.; Cavallazzi, Rodrigo; Singh, Sonal; Loke, Yoon Kong.

In: European Journal of Clinical Pharmacology, Vol. 68, No. 5, 05.2012, p. 747-755.

Research output: Contribution to journalArticle

Kwok, Chun Shing ; Yeong, Jessica Ka Yan ; Turner, Richard M. ; Cavallazzi, Rodrigo ; Singh, Sonal ; Loke, Yoon Kong. / Statins and associated risk of pneumonia : A systematic review and meta-analysis of observational studies. In: European Journal of Clinical Pharmacology. 2012 ; Vol. 68, No. 5. pp. 747-755.
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AU - Kwok, Chun Shing

AU - Yeong, Jessica Ka Yan

AU - Turner, Richard M.

AU - Cavallazzi, Rodrigo

AU - Singh, Sonal

AU - Loke, Yoon Kong

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N2 - Purpose: Statins have potential anti-inflammatory effects, but the association between statin use and lower incidence of pneumonia is unclear. We have therefore performed a systematic review on the risk of pneumonia in statin users versus non-users. Methods: MEDLINE and EMBASE were searched in December 2010 for controlled observational studies that reported on the risk of pneumonia in statin users. We performed a random effects meta-analysis and assessed heterogeneity using the I 2 statistic. Results: A total of 451 citations were screened, and ultimately nine studies (4 case-control, 4 retrospective cohort, 1 prospective cohort) with more than 3 million participants were included in the meta-analysis. Pooled analysis of seven studies that reported unadjusted data failed to show a significantly reduced risk of pneumonia [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.84-1.06, p=0.33, I 2=79%] in statin users as compared to nonusers. However, a significant reduction in the likelihood of pneumonia associated with statin use (n=8 studies, OR 0.85, 95% CI 0.75-0.97, p=0.02, I 2=81%) was found in the meta-analysis of adjusted data. Both analyses were limited by substantial statistical heterogeneity. Sensitivity analysis failed to fully clarify the source of heterogeneity, but cohort studies seemed to be less heterogenous (n=5 studies, OR 0.92, 95% CI 0.84-1.01, I 2=43%). Conclusion: Our findings indicate that the purported benefit of statins in preventing pneumonia is inconsistent, and of low magnitude, with upper bounds of the confidence interval being close to null. In view of the substantial statistical and clinical heterogeneity in the dataset, there is no convincing evidence to support the therapeutic application of statins for reducing the risk of pneumonia.

AB - Purpose: Statins have potential anti-inflammatory effects, but the association between statin use and lower incidence of pneumonia is unclear. We have therefore performed a systematic review on the risk of pneumonia in statin users versus non-users. Methods: MEDLINE and EMBASE were searched in December 2010 for controlled observational studies that reported on the risk of pneumonia in statin users. We performed a random effects meta-analysis and assessed heterogeneity using the I 2 statistic. Results: A total of 451 citations were screened, and ultimately nine studies (4 case-control, 4 retrospective cohort, 1 prospective cohort) with more than 3 million participants were included in the meta-analysis. Pooled analysis of seven studies that reported unadjusted data failed to show a significantly reduced risk of pneumonia [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.84-1.06, p=0.33, I 2=79%] in statin users as compared to nonusers. However, a significant reduction in the likelihood of pneumonia associated with statin use (n=8 studies, OR 0.85, 95% CI 0.75-0.97, p=0.02, I 2=81%) was found in the meta-analysis of adjusted data. Both analyses were limited by substantial statistical heterogeneity. Sensitivity analysis failed to fully clarify the source of heterogeneity, but cohort studies seemed to be less heterogenous (n=5 studies, OR 0.92, 95% CI 0.84-1.01, I 2=43%). Conclusion: Our findings indicate that the purported benefit of statins in preventing pneumonia is inconsistent, and of low magnitude, with upper bounds of the confidence interval being close to null. In view of the substantial statistical and clinical heterogeneity in the dataset, there is no convincing evidence to support the therapeutic application of statins for reducing the risk of pneumonia.

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