Evaluating the quality of life associated with rifabutin prophylaxis for Mycobacterium avium complex in persons with AIDS: combining Q-TWiST and multiattribute utility techniques

Quality-adjusted time without symptoms or toxicity (Q-TWiST): patient-reported outcome or mathematical model? A systematic review in cancer

OBJECTIVE

Successful cancer treatment is defined as an increase in overall survival and/or progression-free survival. Despite their importance, these metrics omit patient quality of life. Quality-adjusted time without symptoms or toxicity (Q-TWiST) was developed to adjust survival gained, accounting for quality of life. The purpose of this systematic review was to assess the methods reported in cancer literature to determine Q-TWiST values and how these are currently translated to the clinic.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were used to conduct a systematic review of studies indexed on MEDLINE and Web of Science through April 2013. Cancer studies that measured Q-TWiST either as a primary outcome or retrospectively and determined utility coefficients from a patient population were identified, and their methods reviewed to determine how the utility coefficient was calculated. Additionally, other relevant factors such as definitions of health states and significant findings were collected and summarized.

RESULTS

Out of 284 studies, 11 were identified that calculated patient-defined utility coefficients. Several methods to determine utility coefficients were reported, and multiple definitions of health state toxicity were applied. Of these studies, seven reported significant differences (p < 0.05) in quality-adjusted survival. No studies, however, directly discussed the clinical relevance of their findings.

CONCLUSIONS

Currently, Q-TWiST is utilized as a mathematical theory rather than a clinical tool. Standardization of terminology plus reliability and validity testing of determining both utility coefficients and time frame definitions must be performed before Q-TWiST can become clinically useful to physicians and patients alike for making treatment decisions.

Health-related quality of life in veterans and nonveterans with HIV/AIDS

PURPOSE

To compare health-related quality of life (HRQoL) between patients receiving care in Veterans Administration (VA) settings (veterans) and non-VA settings (nonveterans), and to explore determinants of HRQoL and change in HRQoL over time in subjects living with HIV/AIDS.

SUBJECTS

One hundred veterans and 350 nonveterans with HIV/AIDS from 2 VA and 2 university-based sites in 3 cities interviewed in 2002 to 2003 and again 12 to 18 months later.

METHODS

We assessed health status (functional status and symptom bother), health ratings, and health values (time tradeoff [TTO] and standard gamble [SG] utilities). We also explored bivariate and multivariable associations of HRQoL measures with a number of demographic, clinical, spiritual/religious, and psychosocial characteristics.

RESULTS

Compared with nonveterans, the veteran population was older (47.7 vs 42.0 years) and consisted of a higher proportion of males (97% vs 83%), of participants with a history of injection drug use (23% vs 15%), and of subjects with unstable housing situations (14% vs 6%; P<.05 for all comparisons). On scales ranging from 0 (worst) to 100 (best), veterans reported significantly poorer overall function (mean [SD]; 65.9 [17.2] vs 71.9 [16.8]); lower rating scale scores (67.6 [21.7] vs 73.5 [21.0]), lower TTO values (75.7 [37.4] vs 89.0 [23.2]), and lower SG values (75.0 [35.8] vs 83.2 [28.3]) than nonveterans (P<.05 for all comparisons); however, in multivariable models, veteran status was only a significant determinant of SG and TTO values at baseline. Among other determinants that were associated with multiple HRQoL outcomes in baseline and follow-up multivariable analyses were: symptom bother, overall function, religiosity/spirituality, depressive symptoms, and financial worries.

CONCLUSIONS

Veterans reported significantly poorer HRQoL than nonveterans, but when controlling for other factors, veteran status was only a significant determinant of TTO and SG health values at baseline. Correlates of HRQoL such as symptom bother, spirituality/religiosity, and depressive symptoms could be fruitful potential targets for interventions to improve HRQoL in patients with HIV/AIDS.

A comparative review of health-related quality-of-life measures for use in HIV/AIDS clinical trials

With the advent of highly active antiretroviral therapy (HAART), HIV-infected patients are living longer and are concerned not only with a treatment's ability to extend their life but also with the quality of the life they are able to lead. Regulatory authorities are also paying closer attention to the use of health-related quality-of-life (HR-QOL) measures in clinical trials and to the subsequent claims that are made based on the results. This paper reviews existing HR-QOL measures reported in the HIV/AIDS literature since 1990 and identifies those most worthy of consideration for use in future clinical trials.A comprehensive review following predefined selection criteria was conducted. Generic and HIV-targeted measures were assessed for content and practicality for the clinical trial setting. The generic measures were additionally reviewed for the ability to produce preference-based index scores and for the existence of normative general population data. Three generic and six HIV-targeted measures met these selection criteria and were then assessed more fully in terms of their development (HIV-targeted measures), psychometric properties and appropriateness for use in clinical trials.It was determined that each of the selected generic measures (i.e. Medical Outcomes Study [MOS] 36-Item Short Form Survey Instrument [SF-36], EQ-5D, Health Utilities Index [HUI]) could serve as a useful adjunct to an HIV-targeted measure in a trial. The Functional Assessment of HIV Infection (FAHI) and MOS-HIV health survey were deemed the two most appropriate HIV-targeted measures. Each of the measures can be self-administered in < or = 10 minutes and there was ample evidence of their excellent psychometric properties. However, they would not be optimal in all HIV-infected subgroups (e.g. treatment naive vs advanced; adolescents vs older adults) targeted for clinical trial interventions. Although there is no one best HR-QOL measure for use in HIV/AIDS clinical trials, based on our review criteria we identified three generic and two HIV-targeted candidate measures. However, these measures have their limitations and it is clear that greater consensus needs to develop regarding more effective and efficient approaches to HR-QOL measurement in HIV/AIDS clinical trials. Along with the increasingly complex HR-QOL measurement task resulting from changes in the HIV-infected population and shifts in the HR-QOL burden associated with HIV infection and its treatment over the past 25 years, it is increasingly important that HR-QOL outcomes become viable endpoints in HIV/AIDS clinical trials.

Nature and correlates of SF-12 physical and mental quality of life components among low-income HIV adults using an HIV service center

OBJECTIVES

This study describes health-related quality of life (HRQOL) among low-income HIV adults using an HIV service center, compares participants' scores to US published norms for the general population and persons with chronic conditions, and examines relationships between patient characteristics, nonadherence, and HRQOL.

METHODS

A cross-sectional survey of individuals on antiretroviral therapy was conducted. The Medical Outcomes Study SF-12 was used to assess HRQOL. Medication nonadherence was assessed using the 9-item Morisky Adherence Scale. Data also were collected on social support, CD4 cell count, and time since diagnosis.

RESULTS

Approximately 84% of the 86 participants were male, 50% were white, and 39% were black. The mean +/- SD Physical component summary (PCS-12) score of 41.0 +/- 12.5 and Mental component summary (MCS-12) score of 41.9 +/- 11.0 were lower than US general population norms (p < 0.001). PCS-12 scores were similar to those of patients with other chronic conditions. Respondents reported lower MCS-12 scores than patients with hypertension and diabetes (p < 0.006). Employment and higher social support had positive associations with PCS-12 scores and nonadherence had a negative association with MCS-12 scores (p < 0.05).

CONCLUSIONS

HRQOL in this sample of low-income HIV adults was comparable to other HIV populations. Identifying strategies for increasing social support and medication adherence for economically disadvantaged persons with HIV/ AIDS may improve their HRQOL.

The economic value of valacyclovir prophylaxis in transplantation

Cytomegalovirus (CMV) infection and disease, with its extensive direct and indirect consequences, adds considerably to the cost of patient management in both solid organ and bone marrow transplantation. Antiviral prophylaxis for CMV infection can offer cost advantages over preemptive therapy and "wait-and-treat" approaches. Valacyclovir has demonstrated efficacy for CMV prophylaxis in renal, heart, and bone marrow transplantation and is cost-effective when compared with placebo in renal transplant recipients at high risk of CMV infection. In reducing CMV infection and disease, valacyclovir prophylaxis appears to be associated with reductions in indirect effects of CMV (acute graft rejection, other opportunistic infections) and, if these effects are considered, the potential exists for even greater savings to be made with valacyclovir therapy. Benefits of valacyclovir in transplantation extend beyond CMV to other herpesviruses and may be increased in some clinical situations by prolonging prophylaxis beyond 3 months.

Cost-effectiveness model of cytomegalovirus management strategies in renal transplantation. Comparing valaciclovir prophylaxis with current practice

BACKGROUND

Cytomegalovirus (CMV) disease may occur following renal transplantation and has been shown to have health and cost consequences in this setting.

OBJECTIVE

To compare the cost effectiveness of different CMV management strategies for renal transplant patients: prophylaxis with (i) oral valaciclovir or (ii) intravenous ganciclovir; viral testing for CMV followed by (iii) pre-emptive therapy with intravenous ganciclovir or (iv) adjustment of immunosuppression and intensive monitoring; or (v) waiting to treat when CMV disease develops.

METHODS

A decision-tree model was constructed that included the different management strategies for the donor seropositive/recipient seronegative (D+R-) population. Clinical outcomes for the D+R- population came from clinical trials. Treatment algorithms and costs for CMV syndrome and tissue invasive disease were developed from published literature and UK physician interviews. One- and 2-way sensitivity analyses were performed.

STUDY PERSPECTIVE

UK National Health Service.

RESULTS

Prophylaxis with either oral valaciclovir or intravenous ganciclovir dominated (lower costs and fewer cases of CMV disease) the pre-emptive treatment and wait-and-treat strategies. The cost per patient was from 157 Pounds to 438 Pounds higher with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis and the incremental cost per case of CMV disease avoided with valaciclovir prophylaxis ranged from 2243 Pounds to 8111 Pounds (1996 values). These results are sensitive to the efficacy of intravenous ganciclovir prophylaxis and CMV management costs.

CONCLUSIONS

For D+R- renal transplant patients, prophylaxis is the dominant (more effective and less costly) management strategy compared with pre-emptive and wait-and-treat strategies. The cost per patient with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis is slightly higher in our base case scenario, but may be lower under reasonable alternative assumptions.

A multi-attribute model of prostate cancer patient's preferences for health states

Multi-attribute utility theory (MAUT) provides a way to model decisions involving trade-offs among different aspects or goals of a problem. We used MAUT to model prostate cancer patients' preferences for their own health state and we compared this model to patients' global judgments of health state utility. 57 patients with prostate cancer (mean age = 70) at two Chicago Veterans Administration health clinics were asked to evaluate health states described in terms of five health attributes affected by prostate cancer: pain, mood, sexual function, bladder and bowel function, and fatigue and energy. Each attribute had three levels that were used to form three clinically realistic health state descriptions (A = high, B = moderate, C = low). A fourth personalized health description (P) matched the patient's current health. We first measured patients' preferences using time trade-off (TTO) judgments for the three health states (A, B, and C) and for their own current health state (P). The TTO for the patient's own health state (P) was standardized by comparing it to TTO judgments for states A and C. We next constructed a multi-attribute model using the relative importance of the five attributes. The MAU scores were moderately correlated with the TTO preference judgments for the personalized state (Pearson r = 0.38, N = 57, p < 0.01). Thus, patients' preference judgments are moderately consistent and systematic. MAUT appears to be a potentially feasible method for evaluating preferences of prostate cancer patients and may prove helpful in assisting with patient decision making.

Associations of clinical parameters with health-related quality of life in hospitalized persons with HIV disease

To assess the associations of clinical parameters with health-related quality of life (HRQOL) in hospitalized patients with HIV a cross-sectional survey and medical record review was conducted. Medical record reviews for clinical data were completed for 217 hospitalized, HIV-positive individuals. HRQOL was measured in face-to-face interviews using a 44-item survey instrument that yielded 11 multi-item scales. Internal consistency reliability was adequate for the 11 HRQOL scales. HRQOL scores were significantly lower for our hospitalized sample compared to a previous sample of ambulatory clinical trial patients. As expected, individuals reporting more days spent in bed due to illness had significantly lower HRQOL than those reporting fewer days spent in bed due to illness. In addition, those with greater severity of illness had significantly lower HRQOL than persons with less severe illness. In multivariate models, severity of illness and the number of disability days due to illness were significantly associated with worse HRQOL, controlling for CD4 count, symptoms and other patient characteristics. Severity of illness and disability days due to illness are associated with poorer functioning and well-being in hospitalized persons with HIV disease. HRQOL measures are useful tools for assessing the effects of HIV disease on the day-to-day life of individuals with HIV disease.

The Quality of Well-Being scale in asymptomatic HIV-infected patients. HNRC Group. HIV Neural Behavioral Research Center

We review applications of the Quality of Well-Being (QWB) scale for use in studies of human immunodeficiency virus (HIV)-infected patients. The QWB scale is a preference-weighted decision theory-based measure that summarizes outcomes in terms of quality-adjusted life years (QALYs). In order to validate the QWB scale for HIV-infected patients, the measure was administered in the University of California, San Diego (UCSD) HIV Neural Behavioral Research Center (HNRC). Data are presented for a cohort of 400 HIV-positive-infected men and 114 HIV-uninfected male controls. The evidence suggests that the QWB scale is a significant prospective predictor of mortality. The QWB scale was concurrently associated with the number of CD4+ lymphocytes and ratings of neurological impairment based upon clinical evaluations. Further, the QWB scale was related to neuropsychological assessments derived from formal tests of cognitive functioning. Neuropsychological impairments may be associated with income loss for affected patients. The QWB scale scores were lower among patients with clinical depression. We conclude that the QWB scale is an appropriate general health outcome measure for use in observational studies and clinical trials for patients with HIV disease.

The effect of mode of administration on medical outcomes study health ratings and EuroQol scores in AIDS

Brief measures of health-related quality of life are being used with increased frequency in AIDS clinical trials. Self-administration of questionnaires can reduce costs in this setting because they require little time. However, the equivalence between self- and interview-administered responses in clinical trials is not known. We evaluated patient and proxy responses to the Medical Outcomes Study HIV Health Survey (MOS-HIV) and the EuroQol. We randomized 68 patients with advanced HIV disease on (1) mode of administration (self vs. interview); (2) type of interview (face-to-face vs. telephone); (3) questionnaire order (MOS-first vs. EuroQol-first); and (4) 2- vs. 3-item response categories for physical limitations. There were few differences in scores between self and interview administration and type of interview. Proxy respondents viewed patients as more impaired than did patients themselves on subjective aspects of health including mental health (63.8 vs. 75.7, p < 0.001), health distress (67.3 vs. 77.1, p = 0.007), pain (64.4 vs. 70.0, p = 0.04), and vitality (48.4 vs. 55.5, p = 0.04). Results concerning questionnaire order and number of response categories were not conclusive. Our results suggest that for patients with advanced HIV disease, data from the MOS-HIV and the EuroQol collected using different modes may be pooled, but that proxy responses should be calibrated.

Physicians' assessments of the utility of health states associated with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infection

An understanding of quality of life (QOL) with human immunodeficiency virus (HIV) is important because the merits of prevention and treatment alternatives may depend substantially on how these interventions affect QOL. Physicians' views about QOL are important, because they influence the therapeutic options that physicians consider or offer, the recommendations that physicians make, and because they are important for the analysis of certain policy questions. We assessed physicians' utilities of health states associated with HIV infection, and hepatitis B virus (HBV) infection; assessment of utilities for HBV was induced to provide a comparison with HIV utilities. We surveyed 200 housestaff and staff physicians in an academic medical centre by anonymous paper-based questionnaire and used the time-tradeoff method to assess physicians' utilities of the health states. On a scale in which 0 was equivalent to death, and 1 was equivalent to good health, the median utilities for asymptomatic HIV infection, symptomatic HIV infection, and AIDS were 0.833, 0.417, and 0.167, respectively (p < 0.01 or each two-way comparison). Median utilities for asymptomatic HBV infection, mildly symptomatic HBV infection, and severely symptomatic HBV infection were 0.917, 0.667, and 0.167, respectively (p < 0.01 for each two-way comparison). Although physicians varied substantially in the ratings of health states, they assessed the utility of life with HIV disease, including asymptomatic infection, as severely reduced. Studies of the effectiveness and cost-effectiveness of preventive and therapeutic interventions for HIV should evaluate the effect of the intervention on utility-based assessments of QOL. Studies that do not assess such effects may significantly underestimate or overestimate the value of these interventions, depending on the intervention's effect on QOL.