Incremental cost-effectiveness analysis of intravenous ganciclovir versus oral ganciclovir in the maintenance treatment of newly diagnosed cytomegalovirus retinitis in patients with AIDS

HEALTH SERVICES RESEARCH METHODS IN PHARMACY: Evaluation of pharmaceutical services: (2) Methods and measures

Numerous studies have been undertaken to evaluate pharmaceutical services. These include both the evaluation of existing practice and assessments of innovative services in both hospital and community settings. Evaluation requires employment of methods and measures to ensure that relevant data on the effects of a programme are obtained. To evaluate a service from different perspectives (eg, acceptability to health professionals or patients, uptake, clinical outcomes or resource implications), a number of methods may be required. The outcomes may also be wide-ranging. Measures must be selected which provide a true reflection of the extent to which these outcomes are, or are not, achieved. Designs and frameworks used in the evaluation of pharmacy services have been discussed previously,1 this paper reviews the methods and measures that have been employed.

Economic evaluation of treatment administration strategies of ganciclovir for cytomegalovirus retinitis in HIV/AIDS patients in Thailand: a simulation study

BACKGROUND

There are many effective interventions, via various routes (intravenous [IV], oral [OR], intravitreal injection [IVT] and intraocular implantation [IMP]), for treating cytomegalovirus retinitis (CMVR) that have become available. There are large variations in treating CMVR in clinical practice in Thailand.

OBJECTIVE

To evaluate the incremental cost-effectiveness ratio (ICER) of providing (i) IVT, (ii) IV/OR and (iii) IMP ganciclovir to patients with HIV/AIDS and CMVR versus providing no treatment.

DESIGN

A simulation study for which the input parameters were derived from a systematic review of the literature, a hospital-based survey and patient interviews.

SETTING

The analysis assumed a Thai healthcare system perspective. However, the model was run using both societal and healthcare provider perspectives.

RESULTS

Our results suggest that IVT ganciclovir was cost effective and the best option for treating patients with CMVR irrespective of whether patients received antiretroviral treatment (ART). In patients receiving ART, moving from IVT to IV/OR ganciclovir was also likely to be a cost-effective option. Offering IMP ganciclovir was not likely to be cost effective. Providing treatments for patients with bilateral CMVR was more cost effective than providing treatments for those with unilateral CMVR, and offering treatments for patients receiving ART was better value for money than treating patients without ART.

CONCLUSIONS

Our models suggest that IV/OR ganciclovir should be recommended for the treatment of unilateral and bilateral CMVR for patients receiving ART in the Thai healthcare system. IVT ganciclovir may also have a role in the treatment of CMVR patients not receiving ART.

The epidemiology, treatment patterns, and costs of cytomegalovirus retinitis in the post-haart era among a national managed-care population

To examine the epidemiology, treatment patterns, and costs of cytomegalovirus (CMV) retinitis treatment in the post-HAART (highly active antiretroviral therapy) era, a retrospective cohort study was performed using data from US managed-care plans from 1997-2002. Cases with CMV retinitis were defined by requiring diagnosis codes for HIV (or AIDS), CMV, and retinitis and claims for anti-CMV treatment. Costs of oral, intravenous, and intraocular treatment periods were examined. The incidence of enrolled HIV or AIDS cases increased from 7 per million members in 1997 to 150 per million members in 2001. The incidence of CMV retinitis decreased from 23 per 10,000 HIV or AIDS cases in 1997 to 8 per 10,000 HIV or AIDS cases in 2001. The average duration of a CMV episode was 192 days and the average cost was 19,576 US dollars. In a multiple linear regression model adjusting for age, gender, insurance type, geographic region, HAART use, and co-existing AIDS-defining illnesses, intraocular and oral treatment periods saved 7135 and US dollars and 6866 US dollars, respectively, per treatment period compared with intravenous treatment (P < 0.05). The incidence of CMV retinitis decreased in this managed-care population during the post-HAART era. Use of oral or intraocular treatment saves costs compared with intravenous treatment in a managed-care environment.

Economic evaluation of systemic treatments for cytomegalovirus retinitis in patients with AIDS

OBJECTIVE

To determine the cost of using systemic therapy to treat newly diagnosed cytomegalovirus (CMV) retinitis in persons with AIDS.

DESIGN

Incidence-based simulation model of CMV treatment from a government payer perspective.

SETTING

Swiss healthcare system.

PATIENTS AND PARTICIPANTS

Patients with AIDS and newly diagnosed CMV retinitis.

INTERVENTIONS

Patients were assigned to 1 of 4 treatment regimens for induction and maintenance therapy: (i) intravenous (IV) cidofovir induction and maintenance (cidofovir IV/IV); (ii) IV foscarnet induction and maintenance (foscarnet IV/IV); (iii) IV ganciclovir induction and maintenance (ganciclovir IV/IV); and (iv) IV ganciclovir induction and oral (PO) ganciclovir maintenance (ganciclovir IV/PO). Following a second relapse, patients were assigned to one of the other regimens.

MAIN OUTCOME MEASURES

Time to first and subsequent progression, duration of maintenance treatment and direct medical expenditures [1998 Swiss francs (SwF)] .

RESULTS

The median time to first progression was longest for cidofovir IV/IV, followed by foscarnet IV/IV, ganciclovir IV/IV and ganciclovir IV/PO. Mean survival was 13 months and mean costs for this period in the base case were lowest in those initially treated with cidofovir (SwF146,742), followed by initial treatment with foscarnet IV/IV (SwF194,809), ganciclovir IV/PO (SwF195,190) and ganciclovir IV/IV (SwF243,964). Costs were most sensitive to changes in efficacy estimates.

CONCLUSIONS

Of the regimens studied, initiation of treatment with systemic cidofovir appears least costly over a 13-month period.