Incremental net benefit and acceptability of alternative health policies: a case study of mass screening for colorectal cancer

The incremental net benefit (INB) and the related acceptability curves for public health programs provide valuable tools for decision making. We proposed to apply them to the assessment of mass screening of colorectal cancer. The now standard guaiac fecal occult blood test (FOBT) is already implemented in several countries. We considered the innovative immunological FOBT and computed tomography colonography (CTC) as competing screening technologies. Using biennial guaiac FOBT as the reference strategy, we estimated the cost-effectiveness of the following alternatives: biennial immunological FOBT, CTC every 5 years (strategy CTC5), and CTC every 10 years (strategy CTC10). Over a 30-year horizon and from the perspective of a third-party payer, we developed a Markov model on a hypothetical cohort of 100,000 subjects at average risk of colorectal cancer. Close expected net benefits between immunological FOBT and CTC5 induced uncertainty in the choice of the optimal strategy. Probabilistic sensibility analysis then suggested that below a willingness to pay (WTP) per life-years gained (LYG) of 8,587 €/LYG, CTC10 was optimal, while CTC5 would be preferred beyond a WTP of 8,587 €/LYG.     

US and UK versions of the EQ-5D preference weights: Does choice of preference weights make a difference?

Background Most US studies that estimate EQ-5D index score generally apply the UK preference weights. We compared the validity of a newly-developed US weights to the UK weights for use of EQ-5D as a measure of health-related quality of life. Methods Data were collected from a randomized clinical trial for patients with HIV (n = 1,126) in the US. Convergent validity was examined by comparing Pearson correlations of EQ-5D index scores with the MOS-HIV Health Survey scale scores and Physical and Mental Health Summary (PHS, MHS) scores using the US and UK weights. Known-groups validity of EQ-5D US versus UK index scores was compared using clinical variables (CD4+ cell count and HIV viral load), and the MOS-HIV PHS and MHS. Score changes in the EQ-5D index from baseline to week 50 were examined using effect size (ES) estimates. Results The mean EQ-5D index scores was slightly higher using US weights than UK weights (0.87 vs. 0.84, respectively). The correlation coefficient for EQ-5D utilities using the US and UK weights was 0.98. The correlations of EQ-5D index scores with the MOS-HIV scores were moderate and similar using the US and UK weights. The EQ-5D index scores discriminated equally well for both versions between levels of CD4+ count, HIV viral load, and PHS and MHS scores (P < 0.05), suggesting equivalent known-groups validity. The changes in EQ-5D index scores from baseline to week 50 were similar for both versions (ES: 0.21 vs. 0.22 for US and UK, respectively), suggesting equivalent responsiveness to score changes. Conclusions EQ-5D index scores generated using UK and US preference weights showed equivalent psychometric properties. For assessing treatment benefit in a single population, the use of either the UK or US weights as a measure of HRQOL will not change inferences. However, for comparisons across US and UK populations, the choice between these two weights should be based on their relevance to the study population.     

Health state preference scores for children with permanent childhood hearing loss: a comparative analysis of the QWB and HUI3

PURPOSE: The aim of this study was to compare two preference-weighted, caregiver-reported measures of health-related quality of life for children with permanent childhood hearing loss to determine whether cost-effectiveness analysis applied to deaf and hard of hearing populations will provide similar answers based on the choice of instrument. METHODS: Caregivers of 103 children in Arkansas, USA, with documented hearing loss completed the Quality of Well-Being Scale (QWB) and the Health Utilities Index Mark 3 (HUI3) to describe the health status of their children. Audiology and other clinical measures were abstracted from medical records. Mean scores were compared overall and by degree of hearing loss. Linear regression was used to correlate preference scores with a four-frequency pure-tone average, cochlear implant status, and other factors. RESULTS: Mean preference scores for the QWB and HUI3 were similar (0.601 and 0.619, respectively) although the HUI3 demonstrated a wider range of values (-0.132 to 1.000) compared to the QWB (0.345-0.854) and was more sensitive to mild hearing loss. Both measures correlated with the pure-tone average, were negatively associated with comorbid conditions and positively associated with cochlear implant status. In the best fitting regression models, similar estimates for cochlear implant status and comorbid conditions were obtained from the two measures. CONCLUSIONS: Despite considerable differences in the HUI3 and the QWB scale, we found agreement between the two instruments at the mean, but clinically important differences across a number of measures. The two instruments are likely to yield different estimates of cost-effectiveness ratios, especially for interventions involving mild to moderate hearing loss.     

Increasing the acceptability of HIV counseling and testing with three C's: Convenience, confidentiality and credibility

Agencies engaged in humanitarian efforts to prevent the further spread of HIV have emphasized the importance of voluntary counseling and testing (VCT), and most high-prevalence countries now have facilities that offer testing free of charge. The utilization of these services is disappointingly low, however, despite high numbers reporting that they would like to be tested. Explanations of this discrepancy typically rely on responses to hypothetical questions posed in terms of psychological or social barriers; often, the explanation is that people fear learning that they are infected with a disease that they understand to be fatal and stigmatizing. Yet when we offered door-to-door rapid blood testing for HIV as part of a longitudinal study in rural Malawi, the overwhelming majority agreed to be tested and to receive their results immediately. Thus, in this paper, we ask: why are more people not getting tested? Using an explanatory research design, we find that rural Malawians are responsive to door-to-door HIV testing for the following reasons: it is convenient, confidential, and the rapid blood test is credible. Our study suggests that attention to these factors in VCT strategies may mitigate the fear of HIV testing, and ultimately increase uptake in rural African settings.     

Medical students'' attitudes to old people and career preference: a comparison of two universities

Medical students' attitudes to old people were compared at broadly similar points in their education at two medical schools, one with a department of health care of the elderly (Nottingham), the other without such a university department (Leeds). The students were tested at both schools before their clinical training in care of the elderly, using a modified Rosencranz-McNevin semantic differential scale to measure general attitudes to old age, and a Likert scale to measure attitudes to medical care. Questions were also asked about career preferences. Both groups of students showed similar general attitudes to ageing. The Nottingham students showed more positive attitudes to care of old people, and this was reflected in career preferences.     

Quality of life measurement in paediatric and adolescent populations with HIV: a review of the literature

Purpose   To review the quality and utility of currently available self-report generic quality of life (QOL) and health-related quality of life (HRQOL) measures for use with children and adolescents with human immunodeficiency virus and/or acquired immunodeficiency syndrome (HIV/AIDS).
Methods   Literature searches were conducted to identify QOL and HRQOL measures developed for, adapted for, or otherwise used with paediatric and adolescent populations with HIV/AIDS. The quality of measures (i.e. item generation techniques, instrument properties including reliability, validity and responsiveness) were compared and critically evaluated.
Results   Nineteen QOL/HRQOL measures were identified. Item content was generated from the respondent (adult) population in only eight (42%) measures. Seventeen (90%) measures reported internal reliability in the accepted range between 0.70 and 0.90 and four (21%) reported reproducibility statistics in this range. Although validity was reported for 19 (100%) measures, only six (32%) showed evidence for three or more properties, with construct validity being the most commonly reported aspect. The authors of eight (42%) measures reported evidence for responsiveness.
Conclusions   While almost all measures reviewed demonstrated adequate psychometric properties, only one-third demonstrated all aspects of validity, and less than half demonstrated responsiveness. None included paediatric or adolescent populations with HIV/AIDS in their development, neglecting to obtain input from target respondents in item generation to determine what health-related and daily functioning factors are of importance to them. Despite noted limitations, the AUQUEI or the SWED-QUAL appear the best currently available generic measure, and the MQOL-HIV the preferred disease-specific measure, at least for use with older adolescents/young adults.     

Changes in expectation of relationship permanence,pregnancy acceptability and desire,and contraceptive use over time among young Latino/a women and men: An exploratory analysis

ObjectiveWe longitudinally assess associations between changes in expectation of relationship permanence—a measure that incorporates both relationship duration and commitment—pregnancy desire and acceptability, and highly effective contraception use among young U.S. Latino/as.Study designWe used multivariable logistic regression to analyze associations between changes in relationship factors, pregnancy acceptability and desire, and contraceptive method use over 6 months among 299 U.S. Latino/a women and men (ages 18–34) in relationships in a longitudinal study (retention rate: 32.4%).ResultsRespondents who found a pregnancy less acceptable at endline than at baseline were more likely to use highly effective contraception at endline (OR 2.97, 95% CI 1.09, 8.08). Respondents estimating an increase in relationship permanence more than one standard deviation of the mean were 4.90 (95% CI 1.17, 20.55) times more likely to use highly effective contraception at endline, compared to those without a change in estimation of relationship permanence.ConclusionIn this longitudinal study of young adult Latino/as in relationships, we found associations between changes in respondents’ perceptions of the acceptability of a pregnancy and expectation of the permanence of their relationship and highly effective contraceptive use. Our findings reiterate the complicated, intertwined links between relationship dynamics, pregnancy orientation, contraception, and time.ImplicationsThe significance of decreased pregnancy acceptability (but not desire) for using highly effective contraception suggests the importance of acknowledging pregnancy acceptability in contraceptive counseling, particularly because providers are more likely to direct Latino/a young adults towards methods that may not fulfill their contraceptive desires. Including discussion of young people’s expectations of relationship permanence may also be meaningful in counseling.     

Air to fat and blood to fat distribution of volatile organic compounds and drugs: linear free energy analyses

Partition coefficients, K(fat), from air to human fat and to rat fat have been collected for 129 volatile organic compounds, VOCs. A linear free energy relationship, LFER, correlates the 129 values of log K(fat) with R(2)=0.958 and a standard deviation, S.D., of 0.194 log units. Use of training and test sets gives a predictive assessment of around 0.20 log units. Combination of log K(fat) with our previously listed values of log K(blood) enables blood/plasma to fat partition coefficients, as log P(fat), to be obtained for 126 VOCs. These values can be correlated with R(2)=0.847, S.D.=0.304 log units; the latter is also our assessment of the predictive capability of the LFER. Values of log P(fat) have been collected for 46 drugs, and can be fitted to an LFER with R(2)=0.811 and S.D.=0.355 log units. Unlike partition into brain or muscle, the data for VOCs and drugs cannot be combined. There are marked discrepancies for PCBs for which partition from blood/plasma into fat is very much less than that calculated from the data on VOCs or from the data on drugs.