[Pneumonia awareness year, 2004: scientific impact through publications in Archivos de Bronconeumología]

Antibiotic expected effectiveness and cost under real life microbiology: evaluation of ertapenem and ceftriaxone in the treatment of community-acquired pneumonia for elderly patients in Spain

Background

Clinical efficacy of antibiotics may be affected by changes in the susceptibility of microorganisms to antimicrobial agents. The purpose of this study is to assess how these changes could affect the initial efficacy of ertapenem and ceftriaxone in the treatment of community-acquired pneumonia (CAP) in elderly patients and the potential consequences this may have in health care costs.

Methods

Initial efficacy in elderly was obtained from a combined analysis of two multicenter, randomized studies. An alternative scenario was carried out using initial efficacy data according to the pneumonia severity index (PSI). Country-specific pathogens distribution was obtained from a national epidemiological study, and microbiological susceptibilities to first- and second-line therapies were obtained from Spanish or European surveillance studies. A decision analytic model was used to compare ertapenem versus ceftriaxone for CAP inpatient treatment. Inputs of the model were the expected effectiveness previously estimated and resource use considering a Spanish national health system perspective. Outcomes include difference in proportion of successfully treated patients and difference in total costs between ertapenem and ceftriaxone. The model performed one-way and probabilistic sensitivity analyses.

Results

First-line treatment of CAP with ertapenem led to a higher proportion of successfully treated patients compared with ceftriaxone in Spain. One-way sensitivity analysis showed that length of stay was the key parameter of the model. Probabilistic sensitivity analysis showed that ertapenem can be a cost-saving strategy compared with ceftriaxone, with a 59% probability of being dominant (lower costs with additional health benefits) for both, elderly patients (>65 years) and patients with PSI >3.

Conclusion

The incorporation of the current antimicrobial susceptibility into the initial clinical efficacy has a significant impact in outcomes and costs in CAP treatment. The treatment with ertapenem compared with ceftriaxone resulted in better clinical outcomes and lower treatment costs for two segments of the Spanish population: elderly patients and patients with severe pneumonia (PSI >3).

[Epidemiology of community-acquired pneumonia]

AIM

To determine the incidence rate, hospital admission, their mortality related factors in community-acquired pneumonia (CAP) in adults in Gipuzkoa.

PATIENTS AND METHODS

Prospective observational multicenter study of patients over 14 years-old with CAP treated by 33 primary care physicians for a year. Confirmation of the radiologist for diagnosis of pneumonia was required. The participating physicians collected the sociodemographic and clinical variables of all patients with CAP seen in the clinic during one year, and followed-up on the 2nd, 10th and 40th day. Same variables were collected from patients who had CAP in the study period and were diagnosed elsewhere.

RESULTS

The number of patients over 14 years old with CAP during the study was 406 for a population of 48,905 inhabitants. The incidence of CAP was 8.3 cases per 1000 inhabitants/year, and included 56% males and 44% females. The mean age was 56.2 years. The rate of hospital admission during the study period was 28.6% and was not related to comorbidity or age. The overall mortality rate was 2.7% with a mean age of 83.7 years, and was only related to age.

CONCLUSIONS

The incidence of CAP was 8.3 cases per 1000 inhabitants per year. Just over one in four CAP required hospitalization and 2.7% of patients with CAP died. Only age was related to mortality.