Marjon van der Pol

Effectiveness of telemonitoring integrated into existing clinical services on hospital admission for exacerbation of chronic obstructive pulmonary disease: researcher blind, multicentre, randomised controlled trial

Objective To test the effectiveness of telemonitoring integrated into existing clinical services such that intervention and control groups have access to the same clinical care. Design Researcher blind, multicentre, randomised controlled trial. Setting UK primary care (Lothian, Scotland). Participants Adults with at least one admission for chronic obstructive pulmonary disease (COPD) in the year before randomisation. We excluded people who had other significant lung disease, who were unable to provide informed consent or complete the study, or who had other significant social or clinical problems. Interventions Participants were recruited between 21 May 2009 and 28 March 2011, and centrally randomised to receive telemonitoring or conventional self monitoring. Using a touch screen, telemonitoring participants recorded a daily questionnaire about symptoms and treatment use, and monitored oxygen saturation using linked instruments. Algorithms, based on the symptom score, generated alerts if readings were omitted or breached thresholds. Both groups received similar care from existing clinical services. Main outcome measures The primary outcome was time to hospital admission due to COPD exacerbation up to one year after randomisation. Other outcomes included number and duration of admissions, and validated questionnaire assessments of health related quality of life (using St George’s respiratory questionnaire (SGRQ)), anxiety or depression (or both), self efficacy, knowledge, and adherence to treatment. Analysis was intention to treat. Results Of 256 patients completing the study, 128 patients were randomised to telemonitoring and 128 to usual care; baseline characteristics of each group were similar. The number of days to admission did not differ significantly between groups (adjusted hazard ratio 0.98, 95% confidence interval 0.66 to 1.44). Over one year, the mean number of COPD admissions was similar in both groups (telemonitoring 1.2 admissions per person (standard deviation 1.9) v control 1.1 (1.6); P=0.59). Mean duration of COPD admissions over one year was also similar between groups (9.5 days per person (standard deviation 19.1) v 8.8 days (15.9); P=0.88). The intervention had no significant effect on SGRQ scores between groups (68.2 (standard deviation 16.3) v 67.3 (17.3); adjusted mean difference 1.39 (95% confidence interval −1.57 to 4.35)), or on other questionnaire outcomes. Conclusions In participants with a history of admission for exacerbations of COPD, telemonitoring was not effective in postponing admissions and did not improve quality of life. The positive effect of telemonitoring seen in previous trials could be due to enhancement of the underpinning clinical service rather than the telemonitoring communication. Trial registration ISRCTN96634935. Funding: The trial was funded by an NHS applied research programme grant from the Chief Scientist Office of the Scottish government (ARPG/07/03). The funder had no role in study design and the collection, analysis, and interpretation of data and the writing of the article and the decision to submit it for publication. NHS Lothian supported the telemonitoring service and the clinical services.

Using conjoint analysis to establish consumer preferences for fruit and vegetables

Considers the technique of conjoint analysis as a method for acquiring insights into the preferences for food products. Applies the technique to establish the trade‐offs that consumers make between price, quality, convenience to prepare and location of purchase in the purchasing of fruit and vegetables. Also uses the technique to estimate indirectly willingness to pay for the included attributes according to income group. Quality was found to be the most important attribute. Reveals, through segmentation of the price attribute by income, that those on higher incomes had a higher marginal valuation of price. Also suggests that respondents understood the questionnaire, and answered it in a meaningful and consistent way. Suggests that the technique could successfully be used to establish consumer preferences for alternative food products that are commercially feasible.

Mapping the EORTC QLQ C-30 onto the EQ-5D instrument: the potential to estimate QALYs without generic preference data.

OBJECTIVES The aim of this article is to map the European Organization for Research and Treatment of Cancer (EORTC) QLQ C-30 onto the EQ-5D measure to enable the estimation of health state values based on the EORTC QLQ C-30 data. The EORTC QLQ C-30 is of interest because it is the most commonly used instrument to measure the quality of life of cancer patients. METHODS Regression analysis is used to establish the relationship between the two instruments. The performance of the model is assessed in terms of how well the responses to the EORTC QLQ C-30 predict the EQ-5D responses for a separate data set. RESULTS The results showed that the model explaining EQ-5D values predicted well. All of the actual values were within the 95% confidence intervals of the predicted values. More importantly, predicted difference in quality-adjusted life-years (QALYs) between the arms of the trial was almost identical to the actual difference. CONCLUSION There is potential to estimate EQ-5D values using responses to the disease-specific EORTC QLQ C-30 measure of quality of life. Such potential implies that in studies that do not include disease-specific measures, it might still be possible to estimate QALYs.

Negative and zero time preference for health

The assumption of positive time preference is seldom challenged in analyses of intertemporal choices, despite considerable evidence of zero and negative discount rates. In this study, the majority of respondents have positive discount rates, but a substantial number have negative or zero discount rates. Using probit regression, the perception of the severity of the health-state, gender, education and perception of the questions in terms of difficulty are shown to influence whether individuals have positive discount rates.

Establishing patient preferences for blood transfusion support: an application of conjoint analysis.

Objective: To develop a method of determining the relative importance of waiting time and location of care for patients with haematological disorders requiring red cell transfusion. Such information is particularly relevant when evaluating interventions that affect patient well-being (e.g. by changing waiting time and location) but do not affect health outcomes. Methods: Conjoint analysis is used to assess the relative importance of waiting time and location with respect to pre-transfusion testing and red cell transfusion. Compensation is also included as an attribute in order to estimate the monetary value of changes in waiting time and location. Results: Waiting time and location are important attributes in the provision of pre-transfusion testing and red cell transfusion. Compensation is not an important attribute. On average patients are willing to wait an additional 45 minutes in order to have pre-transfusion testing in their own home and an additional 35 minutes in order to receive red cell transfusions in their preferred location. Conclusion: The relative importance of waiting time and location of care was established. However, it was not possible to assign monetary values since compensation was not an important attribute for these respondents. The paper highlights the scope for using conjoint analysis to analyse the non-health benefits that may result from changes in the delivery of care.

Saving future lives. A comparison of three discounting models

This paper compares three models of intertemporal choice concerning saving future lives: the constant discounting model, the proportional discounting model and the hyperbolic discounting model. The three models were investigated using data collected from the general public. Since these data have a multilevel structure, ordinary least-squares (OLS) estimates were supplemented by multilevel analysis. There is evidence in favour of the proportional (and to a lesser extent) the hyperbolic model over the constant discounting model. There is clear evidence for this data set that multilevel analysis is more appropriate than OLS.

Constant and decreasing timing aversion for saving lives

The traditional model of time preferences employed by economists is characterised by constant timing aversion. The available evidence suggests that this is not an appropriate assumption. This paper examines evidence for constant and decreasing timing aversion with respect to saving lives. Three discounting models are considered: the constant discounting model; the proportional discounting model; and the hyperbolic discounting model. Data collected from the general public are used to test the constant timing aversion model. Overall, the findings suggest that there is substantial evidence for decreasing timing aversion and against the constant timing aversion hypothesis.

A comparison of the discounted utility model and hyperbolic discounting models in the case of social and private intertemporal preferences for health

Whilst there is substantial evidence that hyperbolic discounting models describe intertemporal preferences for monetary outcomes better than the discounted utility (DU) model, there is only very limited evidence in the context of health outcomes. This study elicits private and social intertemporal preferences for non-fatal changes in health. Specific functional forms of the DU model and three hyperbolic models are fitted. The results show that the stationarity axiom is violated, and that the hyperbolic models fit the data better than the DU model. Intertemporal preferences for private and social decisions are found to be very similar.

Head and neck cancer assessment by flexible endoscopy and telemedicine

We have conducted a feasibility study to establish whether ENT tele-endoscopy would be a suitable method of service delivery for patients who live in the Shetland Islands. Ten clinics were conducted over a period of 17 months using ISDN-based videoconferencing at a bandwidth of 384 kbit/s. A total of 42 patients were seen in Aberdeen via videoconferencing for a head and neck cancer assessment. Feasibility was confirmed after the first 20 patients, following positive feedback from all concerned and the absence of any significant clinical or technical problems. A total of 42 journeys was avoided, each journey saving 123 kg CO2 per person. A preliminary cost analysis showed that the threshold at which tele-ENT became cheaper than travel was a workload of 35 patients/year. The actual workload during the pilot study was 29 patients/year. A national telemedicine service for the initial assessment of potential malignancy has the potential to reduce unnecessary transfers to specialist centres, with accompanying reductions in carbon emissions.

Convergent validity between a discrete choice experiment and a direct, open-ended method: Comparison of preferred attribute levels and willingness to pay estimates

The Discrete Choice Experiment (DCE) has become increasingly popular as a method for eliciting patient or population preferences. If DCE estimates are to inform health policy, it is crucial that the answers they provide are valid. Convergent validity is tested in this paper by comparing the results of a DCE exercise with the answers obtained from direct, open-ended questions. The two methods are compared in terms of preferred attribute levels and willingness to pay (WTP) values. Face-to-face interviews were held with 292 women in Calgary, Canada. Similar values were found between the two methods with respect to preferred levels for two out of three of the attributes examined. The DCE predicted less well for levels outside the range than for levels inside the range reaffirming the importance of extensive piloting to ensure appropriate level range in DCEs. The mean WTP derived from the open-ended question was substantially lower than the mean derived from the DCE. However, the two sets of willingness to pay estimates were consistent with each other in that individuals who were willing to pay more in the open-ended question were also willing to pay more in the DCE. The difference in mean WTP values between the two approaches (direct versus DCE) demonstrates the importance of continuing research into the different biases present across elicitation methods.