Using the Analytic Hierarchy Process to Derive Health State Utilities from Ordinal Preference Data

BackgroundThe EuroQol five-dimensional questionnaire is a standardized instrument used in the economic evaluation of health care to measure health state preferences across disease groups. A time trade-off (TTO) approach is commonly used to elicit preferences from the public. However, there are issues regarding how best to measure worse-than-dead states; at present, extreme valuations are rounded up to more acceptable values. TTO elicitation is also cognitively demanding for respondents and is therefore expensive to investigate.ObjectivesTo describe how the analytic hierarchy process approach could be used to generate utilities from the ordinal relationships between the health states instead of the ordinal relationships between health states, allowing potentially useful preference data to be incorporated rather than excluded as they are at present. It was applied to the Measurement and Valuation of Health study data set, measuring health state preferences for the United Kingdom.MethodsThe analytic hierarchy process approach was explained. Five approaches to structure pairwise comparisons of health state preference were described (two concave, two convex, and one linear).ResultsAll approaches described predicted the rankings of health states well. However, utilities derived followed an unconventional, bunched shape compared with the original Measurement and Valuation of Health TTO study. An approach was identified by optimizing the parameters, minimizing the sum of squared errors between the ordinal “health state ranking” approach and the original TTO-derived utilities.ConclusionsThis approach outlined offers the potential to convert ordinal preference data into cardinal utilities. It is simpler than TTO studies to carry out and removes the need to directly alter results of the preference ranking exercise.     

Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany

Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.     

Novel Reassortant Influenza A(H5N8) Viruses among Inoculated Domestic and Wild Ducks,South Korea, 2014

An outbreak of highly pathogenic avian influenza, caused by a novel reassortant influenza A (H5N8) virus, occurred among poultry and wild birds in South Korea in 2014. The aim of this study was to evaluate the pathogenesis in and mode of transmission of this virus among domestic and wild ducks. Three of the viruses had similar pathogenicity among infected domestic ducks: the H5N8 viruses were moderately pathogenic (0%–20% mortality rate); in wild mallard ducks, the H5N8 and H5N1 viruses did not cause severe illness or death; viral replication and shedding were greater in H5N8-infected mallards than in H5N1-infected mallards. Identification of H5N8 viruses in birds exposed to infected domestic ducks and mallards indicated that the viruses could spread by contact. We propose active surveillance to support prevention of the spread of this virus among wild birds and poultry, especially domestic ducks.     

Pathologic Changes in Wild Birds Infected with Highly Pathogenic Avian Influenza A(H5N8) Viruses,South Korea, 2014

In January 2014, an outbreak of infection with highly pathogenic avian influenza (HPAI) A(H5N8) virus began on a duck farm in South Korea and spread to other poultry farms nearby. During this outbreak, many sick or dead wild birds were found around habitats frequented by migratory birds. To determine the causes of death, we examined 771 wild bird carcasses and identified HPAI A(H5N8) virus in 167. Gross and histologic lesions were observed in pancreas, lung, brain, and kidney of Baikal teals, bean geese, and whooper swans but not mallard ducks. Such lesions are consistent with lethal HPAI A(H5N8) virus infection. However, some HPAI-positive birds had died of gunshot wounds, peritonitis, or agrochemical poisoning rather than virus infection. These findings suggest that susceptibility to HPAI A(H5N8) virus varies among species of migratory birds and that asymptomatic migratory birds could be carriers of this virus.     

Mapping the Clinical Chronic Obstructive Pulmonary Disease Questionnaire onto Generic Preference-Based EQ-5D Values

ObjectivesTo develop a model to predict EuroQol five-dimensional questionnaire (EQ-5D) values from clinical chronic obstructive pulmonary disease (COPD) questionnaire (CCQ) scores.MethodsWe used data from three clinical trials (the Randomized Clinical Trial on Effectiveness of Integrated COPD Management in Primary Care [RECODE], the Assessment Of Going Home Under Early Assisted Discharge [GO-AHEAD], and the Health Status Guided COPD Care [MARCH]). Data were randomly split into an estimation sample and a validation sample. The conceptual similarity between patient-reported CCQ and preference-based EQ-5D scores was assessed using correlation and principal-component analysis. Different types of models were estimated with increasing complexity. We selected the final models on the basis of mean absolute error and root mean square error when comparing predicted and observed values from the same population (internal validity) and from different trial populations (external validity). We also developed models for different country-specific EQ-5D value sets.ResultsThe principal-component analysis showed that the CCQ domains functional state and mental state are associated with four dimensions of the EQ-5D. The EQ-5D dimension pain/discomfort formed a separate construct on which no CCQ item loaded. The mean observed EQ-5D values were not significantly different from the mean predicted EQ-5D values in internal validation samples but did significantly differ in external validation samples. The models underestimated EQ-5D values in milder health states and overestimated them in more severe health states. The predictive ability of the models was similar across different EQ-5D value sets.ConclusionsThe models can predict mean EQ-5D values that are similar to observed mean values in a similar population. The overestimating/underestimating of the low/high EQ-5D values, however, limits its use in Markov models. Therefore, mapping should be used cautiously.     

A new look at osteomyelitis development – Focus on CCR5delta32. Study in patients from Northeast Brazil

IntroductionCCR5 receptor exerts an important role in the host immune response. Osteomyelitis is an inflammatory process and Staphylococcus aureus is the principal causative agent of this bone injury complication. A deletion of 32 bp (CCR5Δ32) in the CCR5 gene seems to protect against HIV-1, S. aureus and other infections. However, the CCR5Δ32 allele has been associated with an increased risk for other diseases.ObjectiveTo investigate the function of CCR5 and to gather data about the relationship of the CCR5Δ32 mutation and the risk of developing osteomyelitis as a complication in patients with bone traumas.MethodsIn a study of 153 patients with bone traumas the presence of the CCRΔ32 mutation was determined by PCR.ResultsIn this study, the CCR5Δ32 allele was present only in the heterozygous form. Osteomyelitis was more frequent in the wild type carriers (94.87%; 37/39) and most of the CCR5Δ32 carriers (87.5%; 14/16) did not present with osteomyelitis.ConclusionThe CCR5Δ32 could be associated with protection against osteomyelitis caused by S. aureus, corroborating the data from Alonzo & Torres study, in which CCR5 receptor is required for S. aureus leukotoxin ED (LukED) cytotoxicity.     

Contributions from extracellular sources of adenosine to the ethanol toxicity in zebrafish larvae

The effects of ethanol exposure on extracellular adenosine sources in zebrafish were evaluated. In the acute treatment, the embryos were exposed to 2% ethanol on day 1 post-fertilization (dpf). In the chronic treatment, the exposure was continued for 2 h/day up to 6dpf. Ecto-5′-nucleotidase activity was assessed by colorimetric method and gene expression determined by RT-qPCR in 7 dpf zebrafish. Body length, ocular distance and surface area of the eyes were registered in animals acutely exposed to ethanol and pretreated with AOPCP (5–500 nM), an ecto-5′-nucleotidase inhibitor, or dipyridamole (10–100 μM), a blocker of nucleoside transport. Both ethanol exposures promoted increased ecto-5′-nucleotidase activity, impaired locomotion and morphology. Ecto-5′-nucleotidase expression was not affected. AOPCP promoted mild prevention of morphological defects caused by acute treatment, while dipyridamole worsened these defects. Early ethanol exposure altered adenosinergic tonus, especially through nucleoside transporters, contributing to morphological defects produced by ethanol in zebrafish.     

Association between urinary biomarkers of exposure to organophosphate insecticides and serum reproductive hormones in men from NHANES 1999–2002

Exposure to organophosphate (OP) insecticides may alter reproductive hormone levels in men and increase the risk for poor reductive health and other adverse health outcomes. However, relevant epidemiology studies in men are limited. We evaluated urinary concentrations of OP metabolites (3,5,6-trichloro-2-pyridinol and six dialkyl phosphates) in relation to serum concentrations of testosterone (T) and estradiol among 356 men aged 20–55 years old from the U.S. National Health and Nutrition Examination Survey. Biomarkers were detected in greater than 50% of the samples, except for diethyldithiophosphate, dimethylphosphate, and dimethyldithiophosphate. In adjusted regression models, we observed a statistically significant inverse relationship between diethyl phosphate (DEP) and T when DEP was modeled as either a continuous or categorical variable. These findings add to the limited evidence that exposure to certain OP insecticides is linked to altered T in men, which may have important implications for male health.