Role of statin on mortality outcome in pneumonia patients: A meta-analysis

Table 1 Summary of the different studies evaluating the effect of statins on mortality in pneumonia

Ref.	Study design	Patient’s setting and study groups	Outcomes and odds ration (95%CI)	Conclusion
Thomsen et al[43], 2008 Preadmission Use of Statins and outcomes After Hospitalization With Pneumonia: Population-Based Cohort Study of 29900 Patients	Retrospective population based cohort study	29900 adults hospitalized with pneumonia for the first time between January 1, 1997, and December 31, 2004 in northern Denmark. Data on statin and other medication use, comorbidities, socioeconomic markers, laboratory findings,bacteremia, pulmonary complications and death were obtained from medical databases. SU: 1371 NSU: 28529	Of patients with pneumonia, 1371 (4.6%) were current statin users. Mortality among statin users was lower than among nonusers: 10.3% vs 15.7% after 30 d and 16.8% vs 22.4% after 90 d, corresponding to adjusted 30- and 90-d mortality rate ratios of 0.69 (95%CI: 0.58-0.82) and 0.75 (0.65-0.86).	The use of statins is associated with de creased mortality after hospitalization with pneumonia
Schlienger et al[14], 2007 Statins and the Risk of Pneumonia: A population-Based, Nested Case-Control Study	Population-based, retrospective, nested case-control analysis	The study population (134262 patients aged > 30 yr) consisted of 55118 patients who took statins and/or fibrates, 29144 patients with hyperlipidemia not taking lipid-lowering agents, and 50000 randomly selected patients without hyperlipidemia and without lipid-lowering treatment. Authors identified 1253 patients with pneumonia and matched them with 4838 control subjects based on age, sex, general practice, and index date.After adjusting for comorbidity and frequency of visits to general practitioners, we calculated the risks (OR with 95% confidence intervals) of uncomplicated pneumonia, hospitalization for pneumonia with survival, and fatal pneumonia in participants who used statins compared with those who did not. SU: 927 NSU: 326	30 d Mortality ratio 0.262 (0.182-0.377)	Significant lower mortality among statin users as compared to non users
Majumdar et al[23], 2006 Statins and outcomes in patients admitted to hospital with community acquired pneumonia: population based prospective cohort study	Prospective population based cohort study	3415 adult patients admitted with CAP and categorised according to use of statins for at least one week before admission and during hospital stay. SU: 325 NSU: 3090	Of 3415 patients with pneumonia admitted to hospital, 624 (18%) died or were admitted to an intensive care unit. Statin users were less likely to die or be admitted to an intensive care unit than non-users [50/325 (15%) vs 574/3090 (19%), OR = 0.80, P = 0.15]. After more complete adjustment for confounding, however, the OR changed from potential benefit (0.78, adjusted for age and sex) to potential harm (1.10, fully adjusted including propensity scores, 95%CI: 0.76-1.60)	Statins are not associated with reduced mortality or need for admission to an intensive care unit in patients with pneumonia; reports of benefit in the setting of sepsis may be a result of confounding.
Mortensen et al[15], 2005 The effect of prior statin use on 30-d mortality for patients hospitalized with community-acquired pneumonia	Retrospective cohort study	A retrospective cohort study conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of, had a chest x-ray consistent with, and had a discharge ICD-9 diagnosis of pneumonia. Subjects were excluded if they were “comfort measures only” or transferred from another acute care hospital. Subjects were considered to be on a medication if they were taking it at the time of presentation. Data was abstracted on 787 subjects at the two hospitals. SU: 110 NSU: 677	In the multivariable regression analysis, after adjusting for the propensity score and processes of care, the use of statins at presentation (OR = 0.36, 95%CI: 0.14-0.92) was significantly associated with decreased 30-d mortality	Prior outpatient statin use was associated with decreased mortality in patients hospitalized with community-acquired pneumonia despite their use being associated with comorbid illnesses likely to contribute to increased mortality

SU: Statin users; NSU: Nonstatin users.

Table 2 Individual and total evaluation number of statin users and nonusers on the mortality in pneumonia in various studies

Ref.	Mortality in SU	Mortality in NSU	OR	95%CI
Thomsen et al[43]	141/1372	4489/28528	0.61	0.514-0.732
Schlienger et al[14]	54/927	229/326	0.262	0.182-0.377
Majumdar et al[23]	25/325	309/3090	0.75	0.491-1.147
Mortensen et al[15]	5/110	67/677	0.434	0.171-1.101
Total (fixed effects)	225/2734	5094/32621	0.373	0.322 - 0.431
Total (Random effects)	225/2734	5094/32621	0.267	0.0499 - 1.428
Test for heterogeneity Computed value	246.1742
Degrees of freedom	3
Significance level	P < 0.05

SU: Statin users; NSU: Nonstatin users.