Cost-Effectiveness Analysis of Diagnostic Options for Pneumocystis Pneumonia (PCP)

Abstract

BackgroundDiagnosis of Pneumocystis jirovecii pneumonia (PCP) is challenging, particularly in developing countries. Highly sensitive diagnostic methods are costly, while less expensive methods often lack sensitivity or specificity. Cost-effectiveness comparisons of the various diagnostic options have not been presented.Methods and FindingsWe compared cost-effectiveness, as measured by cost per life-years gained and proportion of patients successfully diagnosed and treated, of 33 PCP diagnostic options, involving combinations of specimen collection methods [oral washes, induced and expectorated sputum, and bronchoalveolar lavage (BAL)] and laboratory diagnostic procedures [various staining procedures or polymerase chain reactions (PCR)], or clinical diagnosis with chest x-ray alone. Our analyses were conducted from the perspective of the government payer among ambulatory, HIV-infected patients with symptoms of pneumonia presenting to HIV clinics and hospitals in South Africa. Costing data were obtained from the National Institutes of Communicable Diseases in South Africa. At 50% disease prevalence, diagnostic procedures involving expectorated sputum with any PCR method, or induced sputum with nested or real-time PCR, were all highly cost-effective, successfully treating 77–90% of patients at $26–51 per life-year gained. Procedures using BAL specimens were significantly more expensive without added benefit, successfully treating 68–90% of patients at costs of $189–232 per life-year gained. A relatively cost-effective diagnostic procedure that did not require PCR was Toluidine Blue O staining of induced sputum ($25 per life-year gained, successfully treating 68% of patients). Diagnosis using chest x-rays alone resulted in successful treatment of 77% of patients, though cost-effectiveness was reduced ($109 per life-year gained) compared with several molecular diagnostic options.ConclusionsFor diagnosis of PCP, use of PCR technologies, when combined with less-invasive patient specimens such as expectorated or induced sputum, represent more cost-effective options than any diagnostic procedure using BAL, or chest x-ray alone.

Development and Evaluation of a Real-Time PCR Assay for Detection of Pneumocystis jirovecii on the Fully Automated BD MAX Platform

“…Consequently, a number of PCR protocols, including nested PCR and real-time PCR, have been published and evaluated (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Moreover, molecular detection of P. jirovecii in less-invasive patient specimens has also been shown to be cost-effective (20). The interpretation of PCR test results requires quantification because carriage of low numbers of P. jirovecii has been reported to occur without disease (1,21).…”

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

“…Various diagnostic methods performed on several different specimens have been proposed for the diagnosis of this infection (86). Older techniques rely on the visualization of Pneumocystis cysts or trophozoites by use of various stains (methenamine silver, toluidine blue, and calcofluor white) on expectorated or induced sputum specimens or on more invasive specimens, such as BAL fluid or lung tissue biopsy specimens.…”

“…Importantly, though, in choosing among different diagnostic practices, one should also consider the cost associated with their utilization, especially for evaluating diseases that preferentially affect populations of lower socioeconomic status, such as opportunistic infections. To address this issue, Harris et al performed a cost-effectiveness analysis to compare the different diagnostic techniques for Pneumocystis pneumonia (PCP) (86). Their results indicate that toluidine blue staining of induced sputum samples is the most cost-effective among the staining methods, while the performance of BAL greatly increased the cost of each method, without significantly affecting the percentage of people successfully treated.…”

High Diagnostic Value of a New Real-Time Pneumocystis PCR from Bronchoalveolar Lavage in a Real-Life Clinical Setting

“…In this context, it is remarkable that in countries with limited health care resources, PCR from sputum nowadays seems to be of higher diagnostic value and more cost-effective than staining methods from BAL [7]. …”

“…In order to complete the diagnosis, bronchoalveolar lavage (BAL) gained by bronchoscopy is recommended [6]. Induced sputum can be used alternatively [7]. The microbiological diagnosis is normally based on the microscopic detection of pneumocystis by immunofluorescence testing (IFT) or by other staining methods from BAL or sputum.…”