Incidence and Risk of Pneumococcal Pneumonia in Adults with Distinct Underlying Medical Conditions: A Population-Based Study

PURPOSE

This study investigated the incidence of pneumococcal pneumonia requiring hospitalisation among middle-aged and older adults with and without specific underlying medical conditions, evaluating the influence of these conditions in the risk of developing pneumonia.

METHODS

Population-based prospective cohort study included 2,025,730 individuals ≥ 50 years around Catalonia, Spain. The Catalonian information system for the development of research in primary care (SIDIAP) was used to establish baseline characteristics of the cohort (comorbidities and underlying medical conditions). Hospitalisations from pneumococcal pneumonia occurred among cohort members between 01/01/2015 and 31/12/2015 were collected from hospital discharge codes of 68 reference Catalonian hospitals. Cox regression was used to estimate the association between baseline conditions and the risk of developing pneumonia.

RESULTS

Global incidence rate (IR) of hospitalised pneumococcal pneumonia was 82.8 cases per 100,000 persons-year. Maximum IRs (per 100,000 persons-year) emerged among persons with haematological neoplasia (837.4), immunodeficiency (709.2), HIV infection (474.7), severe renal disease (407.5) and chronic pulmonary disease (305.7). In the multivariable analyses, apart from increasing age, HIV infection (hazard ratio [HR] 6.78), haematological neoplasia (HR 6.30), prior all-cause pneumonia (HR 5.27), immunodeficiency (HR 4.57) and chronic pulmonary disease (HR 2.89) were the conditions most strongly associated with an increasing risk. Pneumococcal vaccination did not emerge associated with a reduced risk in our study population (nor PPsV23 neither PCV13).

CONCLUSION

Old age, immunocompromising conditions and chronic pulmonary/respiratory disease are major risk factors for pneumococcal pneumonia in adults. Our data underline the need for better prevention strategies in these persons.

Prevalence of high, medium and low-risk medical conditions for pneumococcal vaccination in Catalonian middle-aged and older adults: a population-based study

Background

Updated population-based data on the frequency and distribution of risk factors for pneumococcal disease is scarce. This study investigated the prevalence of distinct comorbidities and underlying risk conditions related to an increasing risk of pneumococcal disease among Catalonian middle-aged and older adults.

Methods

Cross-sectional population-based study including 2,033,465 individuals aged 50 years or older registered at 01/01/2015 in the Catalonian Health Institute (Catalonia, Spain). The clinical research database of the Information System for the Development of Research in Primary Care (SIDIAP database) was used to identify high-risk (asplenia and/or immunocompromising conditions) and other increased-risk conditions (chronic pulmonary, cardiac or liver disease, diabetes mellitus, alcoholism and/or smoking) among study subjects.

Results

Globally, 980,310 (48.2%) of the 2,033,465 study population had at least one risk condition of suffering pneumococcal disease (55.4% in men vs 42.0% in women, p < 0.001; 41.7% in people 50–64 years vs 54.7% in persons 65 years or older, p < 0.001). An amount of 176,600 individuals (8.7%) had high-risk conditions (basically immunocompromising conditions). On the other hand, 803,710 persons (39.5%) had one or more other risk conditions. In fact, 212,255 (10.4%) had chronic pulmonary diseases, 248,377 (12.2%) cardiac disease, 41,734 (2.1%) liver disease, 341,535 (16.8%) diabetes mellitus, 58,781 (2.9%) alcoholism and 317,558 (15.6%) were smokers.

Conclusion

In our setting, approximately 50 % of overall persons 50 years or older may be considered at-risk population for pneumococcal disease (almost 10 % have high-risk conditions and 40 % have other risk conditions).

Inhaled drugs as risk factors for community-acquired pneumonia

The effect of inhaled drugs in community-acquired pneumonia (CAP) is unclear. This case-control study was designed to determine whether inhaled drugs were risk factors for CAP. All incident cases of confirmed CAP that occurred over 1 yr in patients with chronic bronchitis (CB), chronic obstructive pulmonary disease (COPD) or asthma were included, as well as CB, COPD and asthma controls. Risk factors for CAP and inhaled treatment were recorded during a personal interview. An effect of inhaled drugs on the risk of CAP was observed in COPD and asthma patients after adjusting for the effect of other respiratory diseases and their concomitant treatments. In COPD patients, inhaled steroids had a risk OR of 3.26 (95% CI 1.07-9.98) and in asthma patients inhaled anticholinergics had a risk OR of 8.80 (95% CI 1.02-75.7). In CB patients, no association with CAP was observed for any inhaler. These effects were independent of adjusting variables related to severity and other respiratory and non-respiratory risk factors for CAP, including vaccines. Inhaled β(2)-adrenergic agonists did not show a significant effect on the risk of CAP in any of the respiratory diseases. Inhaled steroids may favour CAP in COPD patients, whereas anticholinergics may favour CAP in asthma patients. It is difficult to differentiate the effect of inhaled therapy from the effect of COPD or asthma severity on the risk of CAP, and these relationships may not be causal, but could call attention to inhaled therapy in COPD and asthma patients.

New evidence of risk factors for community-acquired pneumonia: a population-based study

The aim of the present study was to identify risk factors for community-acquired pneumonia (CAP), with special emphasis on modifiable risk factors and those applicable to the general population. A population-based, case-control study was conducted, with a target population of 859,033 inhabitants aged >14 yrs. A total of 1,336 patients with confirmed CAP were matched to control subjects by age, sex and primary centre over 1 yr. In the univariate analysis, outstanding risk factors were passive smoking in never-smokers aged >65 yrs, heavy alcohol intake, contact with pets, households with >10 people, contact with children, interventions on the upper airways and poor dental health. Risky treatments included amiodarone, N-acetylcysteine and oral steroids. Influenza and pneumococcal vaccine, and visiting the dentist were protective factors. Multivariable analysis confirmed cigarette smoking, usual contact with children, sudden changes of temperature at work, inhalation therapy (particularly containing steroids and using plastic pear-spacers), oxygen therapy, asthma and chronic bronchitis as independent risk factors. Interventions for reducing community-acquired pneumonia should integrate health habits and lifestyle factors related to household, work and community, together with individual clinical conditions, comorbidities and oral or inhaled regular treatments. Prevention would include vaccination, dental hygiene and avoidance of upper respiratory colonisation.

Protective effect of pneumococcal vaccine against death by pneumonia in elderly subjects

The present study assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine to prevent pneumonia and death in older adults in a first-time report between January and December 2002. A prospective cohort study was conducted including all individuals>or=65 yrs of age assigned to one of eight primary care centres in Tarragona, Spain (n=11,241). The primary outcomes were community-acquired pneumonia (hospitalised or outpatient) and death from pneumonia. All pneumonias were validated by checking clinical records. The association between the pneumococcal vaccination and the risk of each outcome was evaluated by means of multivariate Cox proportional-hazard models, adjusted by age, sex, influenza vaccination status, comorbidity and immunological status. Pneumococcal vaccination did not alter the risk of hospitalisation from pneumonia (hazard ratio (HR): 0.80; 95% confidence interval (CI): 0.50-1.28) or overall pneumonia (HR: 0.86; 95% CI: 0.56-1.31), but the vaccine was associated with considerable reductions of death risk from pneumonia (HR: 0.28; 95% CI: 0.09-0.83). In conclusion, these results suggest that pneumococcal polysaccharide vaccine may not be effective in reducing the incidence of pneumonia, but may be able to diminish the severity of the infection. These findings support the effectiveness of the pneumococcal polysaccharide vaccine to prevent mortality caused by pneumonia in older adults, providing a new argument to recommend systematic vaccination in the elderly.