Risk of pneumococcal diseases in adults with underlying medical conditions: a retrospective, cohort study using two Japanese healthcare databases

et al. 2020

Preprint

Background: Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for mortality among hospitalised adults with pneumococcal disease in Singapore. Methods: Retrospective case-cohort study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015-2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design. Results: We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1±15.4yrs, and 65.5% were male. Compared with controls (N=9,181), IPD patients were younger (mean age 61.5±16.3yrs, vs 72.2±16.1yrs in controls; p<0.001) and with less co-morbidities [median Charlson’s score 1 (IQR 0-4), vs 3 (1-5) in controls; p<0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (relative risk ratio=0.20, 95%CI 0.06–0.69; p=0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥85yrs and Charlson’s score >3.Conclusion: Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination was negatively associated with IPD and should be encouraged among high-risk patients.

Section: Discussionmentioning

confidence: 99%

Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a retrospective case-cohort study

et al. 2020

Preprint

“…A Japanese study of 10.4 million individuals demonstrated that younger adults with at least one medical condition were at greater risk of IPD compared to healthy older adults. For example, an adult aged 50-64yrs with an underlying medical condition had a higher risk compared to a healthy adult aged ≥65yrs 28 . Although the overall incidence in younger adults is lower than in older age groups 4,29 , the increased susceptibility of adults <65yrs with chronic diseases suggests that targeted efforts to vaccinate this population might be beneficial in reducing IPD incidence.…”

Section: Discussionmentioning

confidence: 99%

Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a case-control study

et al. 2020

Preprint

Background: Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore. Methods: Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015-2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design. Results: We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1±15.4yrs, and 65.5% were male. Compared with controls (N=9,181), IPD patients were younger (mean age 61.5±16.3yrs, vs 72.2±16.1yrs in controls; p<0.001) and with less co-morbidities [median Charlson’s score 1 (IQR 0-4), vs 3 (1-5) in controls; p<0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio=0.20, 95%CI 0.06–0.69; p=0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥85yrs and Charlson’s score >3.Conclusion: Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectivenessagainst IPD was estimated to be about 80%, and should be encouraged among high-risk patients.

“…A Japanese study of 10.4 million individuals demonstrated that younger adults with at least one medical condition were at greater risk of IPD compared to healthy older adults. For example, an adult aged 50-64yrs with an underlying medical condition had a higher risk compared to a healthy adult aged ≥65yrs 28 . Although the overall incidence in younger adults is lower than in older age groups 4,29 , the increased susceptibility of adults <65yrs with chronic diseases suggests that targeted efforts to vaccinate this population might be bene cial in reducing IPD incidence.…”

Section: Discussionmentioning

confidence: 99%

Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a case-control study

et al. 2020

Preprint

Background: Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore. Methods: Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015-2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design. Results: We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1±15.4yrs, and 65.5% were male. Compared with controls (N=9,181), IPD patients were younger (mean age 61.5±16.3yrs, vs 72.2±16.1yrs in controls; p<0.001) and with less co-morbidities [median Charlson’s score 1 (IQR 0-4), vs 3 (1-5) in controls; p<0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio=0.20, 95%CI 0.06–0.69; p=0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥85yrs and Charlson’s score >3.Conclusion: Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectiveness against IPD was estimated to be about 80%, and should be encouraged among high-risk patients.