Uncertainty in decision-making: value of additional information in the cost-effectiveness of lifestyle intervention in overweight and obese people
Galani C, Al M, Schneider H, Rutten F F
 
 
Record Status

This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.

CRD summary

This study examined the cost-effectiveness of lifestyle intervention in overweight and obese patients and focused on the assessment of the expected value of perfect information. It was concluded that the lifestyle intervention could provide value for money in Switzerland. There was uncertainty around the effectiveness of the lifestyle intervention on the cardiovascular risk factors and utilities. The analysis was based on valid and well described methodology and the authors’ conclusions appear to be valid.

Type of economic evaluation

Cost-utility analysis

Study objective

This study examined the cost-effectiveness of lifestyle intervention in comparison with standard care in overweight patients, with a body mass index (BMI) between 25 and 29.9, and obese patients, with a BMI of 30 or over. The analysis focused on the assessment of the expected value of perfect information (EVPI).

Interventions

The lifestyle intervention consisted of regular physical activity and healthy eating, including a diet rich in fruits and vegetables. Lifestyle intervention group members attended dietician sessions and supervised exercise sessions. The standard care consisted of no intervention for overweight people and basic dietary counselling and physical exercise sessions for obese people.

Location/setting

Switzerland/primary care.

Methods

Analytical approach:

This economic evaluation was based on a probabilistic Markov model with a 60-year time horizon. The authors stated that a societal perspective was adopted.

Effectiveness data:

The clinical inputs for the model came from: a selection of known, relevant published studies, including large epidemiological studies; Swiss federal statistics; and other secondary sources, the designs of which were not reported. A meta-analysis of published randomised controlled trials (RCTs) was carried out to determine the efficacy of the intervention. The key clinical endpoint was the correlation between BMI and the annual risk of developing hypertension, diabetes, and hypercholesterolaemia, which were taken from epidemiological studies.

Monetary benefit and utility valuations:

The utility valuations were derived from three published studies. No other details were given.

Measure of benefit:

Quality-adjusted life-years (QALYs) were the summary benefit measure and were discounted at an annual rate of 3%.

Cost data:

The economic analysis included the costs of the intervention and those associated with obesity complications. Obesity medication costs were not considered. The intervention costs were based on a Finnish study and the complications costs were derived from the literature. Both sets of estimates were adapted to the Swiss setting. Costs incurred after the first year were discounted at an annual rate of 3%. The price year was 2006 and costs were in Swiss francs (CHF).

Analysis of uncertainty:

A probabilistic sensitivity analysis was carried out by assigning probability distributions to the model inputs and a Monte Carlo simulation produced cost-effectiveness acceptability curves (CEACs). The per patient EVPI was calculated as the difference between the expected value of the cost-effectiveness decision made with perfect information and the decision made on the basis of the existing evidence, over a 10-year time horizon. The population EVPI was obtained using the per patient EVPI and an estimated annual incidence of overweight and obese people in Switzerland. The EVPI for specific parameters was also calculated.

Results

The results were reported for ages 30, 40, 50, and 60 years, overweight (BMI: 28) and obese (BMI: 33), men and women. The lifestyle intervention led to a gain of 0.16 to 0.37 QALYs over usual care in overweight and obese patients. The incremental cost of the lifestyle intervention ranged from CHF 388 to CHF 704 in overweight women and from CHF 402 to CHF 438 in overweight men.

When the results were undiscounted, the lifestyle intervention dominated standard care, being less costly and more effective, in obese women aged 40 to 60 years and all four groups of obese men. When a 3% discount rate was applied, the incremental cost-effectiveness ratios with the lifestyle intervention ranged from CHF 1,516 to CHF 4,358 in overweight women, from CHF 195 to CHF 1,922 in obese women, from CHF 1,237 to CHF 2,189 in overweight men, and from CHF 73 to CHF 508 in obese men.

The CEAC indicated that, at a willingness-to-pay threshold of CHF 2,000 for a unit of health gain, the lifestyle intervention had a probability of being cost-effective that ranged from 48% to 91% depending on sex and age group, excluding overweight men and women aged 30 years.

The population EVPI ranged from zero to CHF 6.8 million in overweight people and from zero to CHF 3.2 million in obese people, depending on age, sex, and threshold value. The population EVPI in overweight women was higher than in overweight men reflecting a higher uncertainty. The partial EVPI estimated a higher uncertainty in the model parameters such as utilities, BMI, cardiovascular risk factors, and systolic blood pressure in overweight and obese people.

Authors' conclusions

The authors concluded that the lifestyle intervention could represent value for money in Switzerland. Their analysis highlighted the areas of uncertainty, such as the effectiveness of the lifestyle intervention on cardiovascular risk factors and utilities.

CRD commentary

Interventions:

The selection of the interventions was appropriate and they were likely to be relevant in other health care settings.

Effectiveness/benefits:

The derivation of the clinical inputs was based on a selective approach rather than on a systematic search of the relevant evidence. However, the sources of data appear to have been appropriate, given their relevance (country-specific estimates) or methodological validity (meta-analysis of published RCTs). The authors subjected all the key clinical inputs to analysis of uncertainty. The derivation of the utility values was not clear. These were obtained from published studies, the methods and results of which were also not clearly reported. QALYs are a valid benefit measure, which capture the impact of the interventions on the patients’ health and allow cross-disease comparisons.

Costs:

The types of costs were presented as macro-categories and a breakdown of cost items was not given, which limits the transparency of the economic analysis and prevents an objective assessment of the relevance of these costs to the societal perspective (as the authors stated). The authors used published sources of data, the details of which were not reported. The sensitivity analysis investigated the uncertainty underlying the economic parameters, which was not a key driver of the model. The use of discounting and the price year were reported.

Analysis and results:

The analysis used an appropriate incremental approach to synthesise the costs and benefits and the findings were presented for all age and sex groups. The issue of uncertainty was extensively addressed using specific approaches. The assessment of uncertainty was an explicit objective of the study. In general, the findings were clearly presented and discussed especially with respect to the EVPI. The authors acknowledged that the use of secondary data for costs and non-Swiss epidemiological inputs was a potential limitation of their analysis.

Concluding remarks:

The analysis was based on valid methodology and despite some limited reporting of the sources for cost data, the authors’ conclusions appear to be valid.

Funding

Funded by the Swiss Federal Office of Health (Bundesamtes fur Gesundheit).

Bibliographic details
Galani C, Al M, Schneider H, Rutten F F. Uncertainty in decision-making: value of additional information in the cost-effectiveness of lifestyle intervention in overweight and obese people. Value in Health 2008; 11(3): 424-434
PubMedID
18179675
DOI
10.1111/j.1524-4733.2007.00284.x
Original Paper URL
http://onlinelibrary.wiley.com/cgi-bin/fulltext/120087829/PDFSTART
Other publications of related interest

Galani C, Schneider H, Rutten FF. Modelling the lifetime costs and health effects of lifestyle intervention in the prevention and treatment of obesity in Switzerland. Int J Public Health 2007;52:1-11.

Sculpher M, Claxton K. Establishing the cost-effectiveness of new pharmaceuticals under conditions of uncertainty––When is there sufficient evidence? Value Health 2005;8:433-46.

McGee DL. Body mass index and mortality: a meta-analysis based on person-level data from twenty-six observational studies. Ann Epidemiol 2005;15 87-97.

Lindstrom J, Peltonen M, Toumilehto J. Lifestyle strategies for weight control: experience from the Finnish Diabetes Prevention Study. Proc Nutr Soc 2005;64:81-8.

Indexing Status
Subject indexing assigned by NLM
MeSH
Adult; Aged; Aged, 80 and over; Body Mass Index; Cost-Benefit Analysis; Decision Making; Female; Humans; Life Style; Male; Middle Aged; Obesity /economics /epidemiology /prevention & Overweight /economics /epidemiology /prevention & Prevalence; Risk Factors; Switzerland /epidemiology; Uncertainty; control; control
AccessionNumber
22008101011
Date bibliographic record published
13/05/2009
Date abstract record published
09/09/2009
 
NHS Economic Evaluation Database (NHS EED)
Produced by the Centre for Reviews and Dissemination
Copyright © 2026 University of York
 
Homepage
Options
Print
PDF
 
PubMed record
Original research
 
Share
 

Message for NHS EED database users