Willingness to pay for a quality-adjusted life year: an evaluation of attitudes towards risk and preferences.

BACKGROUND: This paper examines the Willingness to Pay (WTP) for a quality-adjusted life year (QALY) expressed by people who attended the healthcare system as well as the association of attitude towards risk and other personal characteristics with their response. METHODS: Health-state preferences, measured by EuroQol (EQ-5D-3L), were combined with WTP for recovering a perfect health state. WTP was assessed using close-ended, iterative bidding, contingent valuation method. Data on demographic and socioeconomic characteristics, as well as usage of health services by the subjects were collected. The attitude towards risk was evaluated by collecting risky behaviors data, by the subject's self-evaluation, and through lottery games. RESULTS: Six hundred and sixty two subjects participated and 449 stated a utility inferior to 1. WTP/QALY ratios varied significantly when payments with personal money (mean €10,119; median €673) or through taxes (mean €28,187; median €915) were suggested. Family income, area income, higher education level, greater use of healthcare services, and the number of co-inhabitants were associated with greater WTP/QALY ratios. Age and female gender were associated with lower WTP/QALY ratios. Risk inclination was independently associated with a greater WTP/QALY when "out of pocket" payments were suggested. Clear discrepancies were demonstrated between linearity and neutrality towards risk assumptions and experimental results. CONCLUSIONS: WTP/QALY ratios vary noticeably based on demographic and socioeconomic characteristics of the subject, but also on their attitude towards risk. Knowing the expression of preferences by patients from this outcome measurement can be of interest for health service planning.

Economic valuation of health care services in public health systems: a study about Willingness to Pay (WTP) for nursing consultations.

BACKGROUND: Identifying the economic value assigned by users to a particular health service is of principal interest in planning the service. The aim of this study was to evaluate the perception of economic value of nursing consultation in primary care (PC) by its users. METHODS AND RESULTS: Economic study using contingent valuation methodology. A total of 662 users of nursing consultation from 23 health centers were included. Data on demographic and socioeconomic characteristics, health needs, pattern of usage, and satisfaction with provided service were compiled. The validity of the response was evaluated by an explanatory mixed-effects multilevel model in order to assess the factors associated with the response according to the welfare theory. Response reliability was also evaluated. Subjects included in the study indicated an average Willingness to Pay (WTP) of €14.4 (CI 95%: €13.2-15.5; median €10) and an average Willingness to Accept [Compensation] (WTA) of €20.9 (CI 95%: €19.6-22.2; median €20). Average area income, personal income, consultation duration, home visit, and education level correlated with greater WTP. Women and older subjects showed lower WTP. Fixed parameters explained 8.41% of the residual variability, and response clustering in different health centers explained 4-6% of the total variability. The influence of income on WTP was different in each center. The responses for WTP and WTA in a subgroup of subjects were consistent when reassessed after 2 weeks (intraclass correlation coefficients 0.952 and 0.893, respectively). CONCLUSIONS: The economic value of nursing services provided within PC in a public health system is clearly perceived by its user. The perception of this value is influenced by socioeconomic and demographic characteristics of the subjects and their environment, and by the unique characteristics of the evaluated service. The method of contingent valuation is useful for making explicit this perception of value of health services.

Effectiveness of a cognitive behavioral intervention in patients with medically unexplained symptoms: cluster randomized trial.

BACKGROUND: Medically unexplained symptoms are an important mental health problem in primary care and generate a high cost in health services.Cognitive behavioral therapy and psychodynamic therapy have proven effective in these patients. However, there are few studies on the effectiveness of psychosocial interventions by primary health care. The project aims to determine whether a cognitive-behavioral group intervention in patients with medically unexplained symptoms, is more effective than routine clinical practice to improve the quality of life measured by the SF-12 questionary at 12 month. METHODS/DESIGN: This study involves a community based cluster randomized trial in primary healthcare centres in Madrid (Spain). The number of patients required is 242 (121 in each arm), all between 18 and 65 of age with medically unexplained symptoms that had seeked medical attention in primary care at least 10 times during the previous year. The main outcome variable is the quality of life measured by the SF-12 questionnaire on Mental Healthcare. Secondary outcome variables include number of consultations, number of drug (prescriptions) and number of days of sick leave together with other prognosis and descriptive variables. Main effectiveness will be analyzed by comparing the percentage of patients that improve at least 4 points on the SF-12 questionnaire between intervention and control groups at 12 months. All statistical tests will be performed with intention to treat. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis. DISCUSSION: This study aims to provide more insight to address medically unexplained symptoms, highly prevalent in primary care, from a quantitative methodology. It involves intervention group conducted by previously trained nursing staff to diminish the progression to the chronicity of the symptoms, improve quality of life, and reduce frequency of medical consultations. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT01484223 [http://ClinicalTrials.gov].

[Quality of life related to health as a factor explaining the use of family medical consultation: a study on the behavioral model]. / La calidad de vida relacionada con la salud como factor explicativo de la utilización de la consulta de medicina de familia: un estudio bajo el modelo conductual.

BACKGROUND: Health services utilization has been studied under several conceptual models. This study is aimed to assess the influence of Health Related Quality of Life (HRQL) on the variability of the primary care consultation utilization under the <> METHODS: A cross-sectional study. Interviews were conducted with 451 subjects at six health centers in the Community of Madrid. Environmental and individual characteristics (predisposing, enabling and need factors) and HRQL (EuroQol-5D) were collected. Annual visits were retrieved from the computerized clinical history. RESULTS: Median utilization was 13 visits/year (interquartile range 7-20). HRQL explained 5,2% of utilization variability, living in high-income areas an additional 2.4%, age a 7.4%, incomes a 1.0% and <> (chronic illnesses or a hospital admission in the last year) explained an additional 4.1% of the variability. Each increase of the tercile in the perception of HRQL was associated with a decrease of 13,8% of the number of visits/year. Living in high-income areas, and each increase of 1000 in the incomes decreased the percentage of annual visits 17.5 % and 9.5% respectively. Age is associated with an increase of 8.0% of annual visits per decade. Suffering from chronic illnesses or a hospital admission in the last year increased the average number of visits/year to 51.9 and 26.5%. CONCLUSIONS: HRQL is independently associated with the variability of the demand for the family physician after adjusting by << health need>> factors as the <> proposes.

Differences between willingness to pay and willingness to accept for visits by a family physician: a contingent valuation study.

BACKGROUND: The economic value attributed by users of health services in public health systems can be useful in planning and evaluation. This value can differ from the perspectives of Willingness to Pay (WTP) and Willingness to Accept [Compensation] (WTA).Our objective was to study the perceptions of the patient about the service provided by the family physician by means of the WTA/WTP ratio. METHODS: An economic evaluation study by the Contingent Valuation Method was designed. Interviews were conducted with 451 subjects at six health centres (four urban and two rural) in areas with different socioeconomic characteristics. A payment card was used to measure the WTP and WTA. Other characteristics of the subject or service that could influence these responses were collected. An explicative model was constructed to study the WTA/WTP relationship. RESULTS: Four hundred and four subjects (89.6%) expressed a WTP and WTA different from zero. The WTA/WTP quotient showed a median of 1.55 (interquartile range 1-3.08) and a mean of 3.30 (IC 95%: 2.84-3.75). The WTA/WTP ratio increases with age and in low-income areas. It decreases in professional groups with more specialized activities, with growing family income, and in the chronically ill. Other characteristics related to the perception of state of health, accessibility to the service, satisfaction, or perception of risk were not explicative. CONCLUSIONS: Subjects who were older and had a less favourable socioeconomic situation expressed a higher WTA/WTP ratio when valuing the visit to the family physician. These characteristics could identify a profile of "aversion to loss" with respect to this service.

Comparison of levels of antiretroviral drugs with efficacy in children with HIV infection.

OBJECTIVE: To determine the prevalence of low and high antiretroviral (ARV) plasma levels and to analyze correlation between ARV concentrations and the appearance of therapeutic failure and toxicity. METHODS: The authors present here a study evaluating antiretroviral plasma concentrations in HIV infected children on nonnucleoside reverse transcriptase inhibitors and protease inhibitors based therapy. The authors carried out a multicentre, cross-sectional study, including HIV-infected children from five large Hospitals in Madrid, Spain. Clinical, haematological, biochemical and immuno-virological parameters were assessed. Antiretroviral plasma trough levels were performed using a validated high performance liquid chromatography method. RESULTS: Between April 2006 and April 2008, 129 children were enrolled in the present study, with median treatment duration of 39.2 months. 25.5% of the non-nucleoside reverse transcriptase inhibitors levels were low and 17.6%, high. 27.9% percent of the protease inhibitors levels were low and 12.5%, high. A correlation was found among adequate or high levels of antiretrovirals and normal CD4 percentage and low viral load. Lopinavir/ritonavir plasma levels were correlated with an increase in lipodystrophy. Patients with Tanner stage 1 presented the lowest ARV plasma levels. Full adherence was reported for all the participants by a questionnaire. CONCLUSION: Many HIV-infected children show ARV plasma levels out of the therapeutic range which demands a child-adjusted approach. However, larger studies are urgently needed in pediatric populations to define optimal reference values.

Relation of dental wear to the concentrations of essential minerals in teeth of the California sea lion Zalophus californianus californianus.

Tooth wear in marine mammals has been attributed to age, feeding habits, behavior, and contaminants. Advanced tooth wear in some California sea lions, including some of very young age (<5 yr), in the Gulf of California, suggests that there are variations in chemical composition of tooth parts, wherein the concentrations of certain trace minerals might be anomalous, making them more susceptible to erosion. The concentrations of the essential minerals Ca, P, K, Na, Fe, Mg, and Zn in the dentition of Zalophus c. californianus are documented for the first time and are compared for sea lion teeth with different degrees of wear. Canine teeth and molars from 45 skulls collected at 15 localities since 1978 were digested in perchloric acid and analyzed using atomic adsorption spectrometry, the results being expressed in milligrams per 100 g. An index of tooth wear (Id) was established, involving the average wear on the teeth and the age of the organism. No significant difference was detected in the variables, but there was one between ages (p = 0.02). A higher degree of wear was observed up to 7 yr of age than from this age onward. Mineral concentrations did not explain the excessive wear observed (correlation, p > 0.09; ANOVA, p > 0.15); however, the Ca concentration of the teeth was inversely proportional to the age of the animal (sexes combined, p = 0.026) and particularly significant for the females (r2 = 0.112, r = -0.335, p = 0.039). Females could be more prone to decalcification because of their annual bone investment in their offspring. Animals of both sexes were susceptible to tooth wear as their age increased, but the higher frequency of animals between 4 and 7 yr suggests an impact on survival at early stages probably linked to deficient feeding and chronic malnutrition.

Positive virological outcome after lopinavir/ritonavir salvage therapy in protease inhibitor-experienced HIV-1-infected children: a prospective cohort study.

BACKGROUND: Lopinavir/ritonavir has demonstrated antiviral activity in the HIV-infected patient. OBJECTIVE: To analyse virological response to lopinavir/ritonavir therapy in previously protease inhibitor (PI)-experienced HIV-1-infected children. MATERIALS AND METHODS: Sixty-seven HIV-1-children on lopinavir/ritonavir were studied in a multicentre prospective cohort observational study. The outcome variables were undetectable viral load (uVL; VL < or =400 copies/mL) and virological failure after uVL with a rebound of VL >400 copies/mL. VL and genotype of HIV-1-isolates were measured using standard assays. RESULTS: 83.5% of children had a 1 log10 VL decrease including 65.6% who reached uVL. Children with >2 changes of antiretroviral therapy (ART) or >5 drugs needed a median time of 3-4 months higher than children with < or =2 changes of ART or < or =5 drugs previous to lopinavir/ritonavir, to reach those values, and the relative proportions (RP) were 2.2 (P =0.038) and 1.9 (P=0.050), respectively. Children with CD4+>15% (P=0.122), VL < or =30,000 (P < 0.001) copies/mL, and age >12 years (P=0.096) achieved an earlier control of VL during the follow-up. The children with virological failure or rebound of VL had higher baseline VL and lower CD4+ T-lymphocytes/mm3 and had taken a greater number of drugs previous to lopinavir/ritonavir. HIV-children with a new nucleoside reverse transcriptase inhibitor (NRTI), or protease inhibitor (PI) or PI plus non-nucleoside reverse transcriptase inhibitors (NNRTI) in the current regimen had a better virological response than children without these new drugs. Also, children with <6 protease mutations had an RP of 2.31 of achieving uVL. CONCLUSIONS: Highly active antiretroviral therapy (HAART) including lopinavir/ritonavir induces beneficial effects in terms of virological outcome responses, and it is an effective option for salvage therapy in PI-experienced HIV-1-infected children.