Antiretroviral therapy in HIV-infected individuals in clinical practice: are the criteria for initiating and choosing the type of drug regimen based only on immunologic and virologic values?

CD4 cell count and initiation of antiretroviral therapy: trends in seven UK centres, 1997-2003

OBJECTIVES

We examined whether the timing of initiation of antiretroviral therapy (ART) in routine clinical practice reflected treatment guidelines, which have evolved towards recommending starting therapy at lower CD4 cell counts.

METHODS

We analysed longitudinal data on 10,820 patients enrolled in the UK Collaborative HIV Cohort (UK CHIC) Study, which includes seven large clinical centres in south-east England. CD4 cell and viral load measurements performed in the period between 1 January 1997 and 31 December 2003 were classified according to whether ART was subsequently initiated or deferred, to estimate the probability of ART initiation by CD4 count and viral load over time. The effect of nonclinical factors (age, sex, ethnicity, and exposure category) was analysed by logistic regression. Kaplan-Meier analysis was used to estimate the proportion of patients who had initiated ART by a particular CD4 count among 'early' presenters (initial CD4 cell count >500 cells/microL).

RESULTS

There was a tendency to initiate ART at lower CD4 cell counts over time in the years 1997-2000, especially in the range 200-500 cells/microL, with little change thereafter. An estimated 34% of HIV-infected individuals having presented early initiated ART at a CD4 count <200 cells/microL. We also found an independent influence of viral load, which was particularly pronounced for CD4 <350 cells/microL. Use of injection drugs was the only nonclinical factor associated with initiation of ART at lower CD4 cell counts.

CONCLUSIONS

The initiation of ART in the clinics included in this analysis reflected evolving treatment guidelines. However, an unexpectedly high proportion of patients started ART at lower CD4 counts than recommended, which is only partly explained by late presentation.

Differential diffusion of HIV technologies by gender: the case of highly active antiretroviral therapy

We sought to examine whether diffusion of new HIV technologies differed by gender in the United States, the source of any such disparities, and whether disparities narrow over time as technologies become more established. In particular, we assess how rates of use of highly active antiretroviral therapy (HAART) varied between males and females during the late 1990s, when HAART was rapidly diffusing. We examined data from a prospective cohort study of a national probability sample of 1421 HIV-infected adults in medical care who were enrolled in the HIV Cost and Services Utilization Study (HCSUS) from January 1996 to December 1998. We found that HAART use substantially increased between 1996 and early 1998 for all groups. Women were less likely to receive HAART at all time points, although the diffusion of HAART between 1996 and 1998 reduced gender disparities. Gender disparities in 1998 were only partially explained by women's lower income and educational levels. We conclude that HAART therapy diffused more slowly to HIV-positive females than other groups. Policies that reduce the impact of income and education inequalities on health care may help to narrow gender disparities for new HIV technologies, but other factors may also disadvantage women.

Influence of gender and HIV transmission group on initial highly active antiretroviral therapy prescription and treatment response

BACKGROUND

The literature contains conflicting findings on the influence of gender and HIV transmission group on the initial prescription of highly active antiretroviral therapy (HAART) and its biological and clinical efficacy.

METHODS

We conducted a cohort study involving 62 French hospitals. We used Cox proportional hazards models to examine whether gender and HIV transmission group influenced the timing of elective HAART initiation, and the clinical and biological response to treatment.

RESULTS

We studied 5735 patients enrolled between January 1997 and December 2001 who did not start HAART or develop a stage C HIV-related event during the first 3 months after inclusion. In multivariate analysis, no gender differences were found in the interval between enrollment in the database and HAART initiation, but this interval was shorter in homosexual patients than in other transmission groups; CD4 cell counts at treatment initiation were also higher in the homosexual group. The immunovirological response to treatment did not differ according to gender, but was better in homosexual patients than in patients in other categories. Injecting drug users had the weakest immunovirological responses. Clinical outcome was not related to gender or to HIV transmission group.

CONCLUSIONS

The interval between diagnosis of HIV-1 infection and elective HAART initiation was not influenced by gender. However, homosexual patients had higher CD4 cell counts than other patients at treatment initiation, and also had better immunovirological responses.

Longitudinal trends in antiretroviral use in a cohort of men and women in Ontario, Canada

Initial studies have shown impaired access to antiretrovirals and slower adoption of new therapies by women. It is unclear if similar treatment delays still occur, especially in those with a publicly funded health care system in Ontario, Canada. The objectives of this study were (1) to evaluate longitudinal patterns of antiretroviral use in patients with HIV in Ontario and (2) to determine if gender differences exist in access to and uptake of antiretroviral drugs over time. A retrospective medical chart review was undertaken. One hundred four HIV-positive patients were recruited from nine hospital-based HIV outpatient clinics throughout Ontario. From time of study enrollment in 1999-2001 to the first clinic visit (8.1 +/- 3.2 years; range, 2.3-16.8 years), CD4+ T-cell counts, date of and agents used in initial antiretroviral regimen, and first HAART regimen were evaluated by gender. Kaplan-Meier plots were used to evaluate time to drug initiation from known HIV diagnosis. Serial cross sections of numbers and types of antiretroviral drugs prescribed in March, June, September, and December 1988 to 2001 were also compared as was number of regimens used. There were few differences between men and women in antiretroviral use; both initiated therapy within 2.2 +/- 2.3 years of HIV diagnosis at an average CD4 counts of 300.3 +/- 150.1 cells per microliter. Antiretroviral treatment regimens changed over time, with limited variation by gender. In the period immediately surrounding the first highly active antiretroviral therapy (HAART) recommendations by the U.S. Department of Health and Human Services in July 1997, significantly more antiretroviral drugs were prescribed for men than women. Antiretroviral prescribing in patients attending hospital- based HIV outpatient programs in Ontario is consistent with antiretroviral treatment guidelines over time, without substantial differences in antiretroviral access and use by gender.

Economic evaluation of HIV treatments: The I.CO.N.A. cohort study

OBJECTIVE

To describe the changes in costs of care for HIV-positive patients in Italy after the spread of antiretroviral combination therapies (HAART).

METHODS

Five thousand four hundred and twenty-two patients from the I.CO.N.A. (Italian Cohort Naive Antiretrovirals) study were followed between 1997 and 2002. Costs included antiretroviral therapies (ART), hospital admissions, prophylaxis, and main laboratory examinations. The perspective was that of the National Health Service.

RESULTS

Admission costs per person-year decreased from 2148 euro in 1997 to 256 in 2002, while the average annual costs of ART increased from 2145 to 3149 euro (1997 prices). From 1997 to 1999, ART costs increased from 42.3 to 85.9% of the total, while admission costs decreased from 42.3 to 7.0% and prophylaxis from 7.3 to 1.7%. The breakdown of ART costs shows how dual therapies decreased over time in favor of HAART, falling from 26.8% in 1997 to 5.9% in 2002. Patients with fewer than five treatment switches had the lowest costs distributions over the entire observation period.

CONCLUSIONS

From 1997 to 2002 inpatient costs progressively decreased in favor of antiretroviral therapy. Annual average costs per patient decreased, while total direct costs increased over time: health resources, initially concentrated on hospitalized patients were then distributed over a growing number of subjects.

Hepatitis C infection increases the risk of the modification of first highly active antiretroviral therapy in HIV-infected patients

We assessed predictors of discontinuation or change of the first regimen of highly active antiretroviral therapy in 465 HIV-infected adults, in the first year. A total of 187 patients modified their regimen: 45 discontinuing and 142 changing because of clinical/virological failure, intolerance/toxicity or non-adherence. Predictors of modification of the regimen were hepatitis C seropositivity, liver cirrhosis, higher baseline viral load, sex (women had a lower risk) and calendar year (lower risk staring in 2000).