Evaluation of three methods assessing the relative value of a dental program

People's Willingness to Pay for Dental Checkups and the Associated Individual Characteristics: A Nationwide Web-Based Survey among Japanese Adults

This study aimed to determine the willingness-to-pay (WTP) values for dental checkups and analyze the association between the values and individual characteristics. This cross-sectional study was conducted using a nationwide web-based survey, and 3336 participants were allocated into groups that received regular dental checkups (RDC; n = 1785) and those who did not (non-RDC; n = 1551). There was a statistically significant difference in the WTP value for dental checkups between the RDC (median: 3000 yen [22.51 USD]) and non-RDC groups (2000 yen [15.01 USD]). In the RDC group, age 50-59 years, household income <2 million yen, homemaker and part-time worker employment status, and having children were significantly associated with decreased WTP values; male sex, household incomes ≥8 million yen, and tooth brushing ≥3 times daily were associated with increased WTP values. In the non-RDC group, age ≥30 years, household incomes <4 million yen, and having ≥28 teeth were significantly associated with decreased WTP values; household income ≥8 million yen was associated with increased WTP values. Conclusively, WTP values for dental checkups were lower in the non-RDC group than in the RDC group; in the non-RDC group, those with lower household income aged ≥30 years were more likely to propose lower WTP values, suggesting the need for policy intervention to improve access to RDC.

Prevalence of Missing Values and Protest Zeros in Contingent Valuation in Dental Medicine

Background: The number of contingent valuation (CV) studies in dental medicine using willingness-to-pay (WTP) methodology has substantially increased in recent years. Missing values due to absent information (i.e., missingness) or false information (i.e., protest zeros) are a common problem in WTP studies. The objective of this study is to evaluate the prevalence of missing values in CV studies in dental medicine, to assess how these have been dealt with, and to suggest recommendations for future research. Methods: We systematically searched electronic databases (MEDLINE, Web of Science, Cochrane Library, PROSPERO) on 8 June 2021, and hand-searched references of selected reviews. CV studies in clinical dentistry using WTP for valuing a good or service were included. Results: We included 49 WTP studies in our review. Out of these, 19 (38.8%) reported missing values due to absent information, and 28 (57.1%) reported zero values (i.e., WTP valued at zero). Zero values were further classified into true zeros (i.e., representing the underlying preference of the respondent) or protest zeros (i.e., false information as a protest behavior) in only 9 studies. Most studies used a complete case analysis to address missingness while only one study used multiple imputation. Conclusions: There is uncertainty in the dental literature on how to address missing values and zero values in CV studies. Zero values need to be classified as true zeros versus protest zeros with follow-up questions after the WTP elicitation procedure, and then need to be handled differently. Advanced statistical methods are available to address both missing values due to missingness and due to protest zeros but these are currently underused in dental medicine. Failing to appropriately address missing values in CV studies may lead to biased WTP estimates of dental interventions.

An overview of the methodological aspects and policy implications of willingness-to-pay studies in oral health: a scoping review of existing literature

Background

Demands for dental services seem to be beyond the capacities of most healthcare systems these days. Patient preferences have been increasingly emphasized to be considered in the joint decision-making process. Willingness-to-pay (WTP) is a recommended method for measuring the utility of health services; increasingly being used in recent decades. Taking these points into consideration, this article aims to provide an overview of the methodological aspects and policy implications of WTP studies in the field of oral health.

Methods

The research was conducted in ISPOR, PubMed and Google Scholar databases. In addition, reference lists of included articles were checked to identify the relevant studies. All studies published were included that were in the English language and reported using WTP for oral health-related goods and services. A data-charting form was developed by a focus group discussion panel of seven experts to derive the main methodological aspects of WTP. Also, Core policy suggestions were categorized through thematic content analysis of the included papers.

Results

The search strategy yielded 389 studies of which 52 were included. WTP studies in oral health show an increasing trend in global publications. The UK and Canada have a greater share in published material than in any other country. The dominant field of these researches is in restorative and prosthetic dentistry, and a wide range of different methodological aspects was documented. Policy suggestions were categorized in three main themes: (A) setting new tariffs or subsidizing the item, (B) provision of the item due to population preferences, and (C) improving literacy regarding the item.

Conclusions

An urgent need for a common framework regarding the design of WTP studies in dentistry seems paramount. Some policy suggestions seem not to be applicable, perhaps due to insufficient familiarity of the researchers with the complexities of the public policymaking process.

Critical review of willingness to pay for clinical oral health interventions

OBJECTIVES

This critical review aimed to identify, consolidate and evaluate the quality of Willingness to Pay (WTP) studies applied to clinical contexts in the field of dentistry.

METHODS

PubMed and Web of Science databases were systematically searched for relevant publications. Screening and data extraction was then performed. Primary literature in English-language were included to assess the WTP for oral health interventions, when the valuations were applied to a clinical measure. Twenty-six publications met the inclusion criteria.

RESULTS

WTP was elicited mainly via face-to-face interviews (13 publications) and questionnaires (12 publications). The majority (24) of publications selected an out-of-pocket payment vehicle. Eleven publications adopted a bidding method, nine publications adopted an open-ended format, and the remaining six studies adopted a payment card or choice method. Pre-testing was reported in only nine publications, and few studies accounted for starting point bias. Eight of 11 publications found that higher incomes were associated with higher WTP values. The female gender, a younger age and higher education levels were associated with a higher WTP in select studies.

CONCLUSIONS

Only a small minority of the studies used strategies to avoid well documented biases related to WTP elicitation. Cost versus benefit of many clinical scenarios remain uninvestigated.

CLINICAL SIGNIFICANCE

WTP studies in dentistry may benefit from pre-testing and the inclusion of a script to minimise hypothetical bias. They may also be better conducted face-to-face and via a shuffled payment card method. Income levels, and potentially education levels, gender and age, should be assessed for their influence on WTP values.

Determinants of demand for total hip and knee arthroplasty: a systematic literature review

BACKGROUND

Documented age, gender, race and socio-economic disparities in total joint arthroplasty (TJA), suggest that those who need the surgery may not receive it, and present a challenge to explain the causes of unmet need. It is not clear whether doctors limit treatment opportunities to patients, nor is it known the effect that patient beliefs and expectations about the operation, including their paid work status and retirement plans, have on the decision to undergo TJA. Identifying socio-economic and other determinants of demand would inform the design of effective and efficient health policy. This review was conducted to identify the factors that lead patients in need to undergo TJA.

METHODS

An electronic search of the Embase and Medline (Ovid) bibliographic databases conducted in September 2011 identified studies in the English language that reported on factors driving patients in need of hip or knee replacement to undergo surgery. The review included reports of elective surgery rates in eligible patients or, controlling for disease severity, in general subjects, and stated clinical experts' and patients' opinions on suitability for or willingness to undergo TJA. Quantitative and qualitative studies were reviewed, but quantitative studies involving fewer than 20 subjects were excluded. The quality of individual studies was assessed on the basis of study design (i.e., prospective versus retrospective), reporting of attrition, adjustment for and report of confounding effects, and reported measures of need (self-reported versus doctor-assessed). Reported estimates of effect on the probability of surgery from analyses adjusting for confounders were summarised in narrative form and synthesised in odds ratio (OR) forest plots for individual determinants.

RESULTS

The review included 26 quantitative studies-23 on individuals' decisions or views on having the operation and three about health professionals' opinions-and 10 qualitative studies. Ethnic and racial disparities in TJA use are associated with socio-economic access factors and expectations about the process and outcomes of surgery. In the United States, health insurance coverage affects demand, including that from the Medicare population, for whom having supplemental Medicaid coverage increases the likelihood of undergoing TJA. Patients with post-secondary education are more likely to demand hip or knee surgery than those without it (range of OR 0.87-2.38). Women are as willing to undergo surgery as men, but they are less likely to be offered surgery by specialists than men with the same need. There is considerable variation in patient demand with age, with distinct patterns for hip and knee. Paid employment appears to increase the chances of undergoing surgery, but no study was found that investigated the relationship between retirement plans and demand for TJA. There is evidence of substantial geographical variation in access to joint replacement within the territory covered by a public national health system, which is unlikely to be explained by differences in preference or unmeasured need alone. The literature tends to focus on associations, rather than testing of causal relationships, and is insufficient to assess the relative importance of determinants.

CONCLUSIONS

Patients' use of hip and knee replacement is a function of their socio-economic circumstances, which reinforce disparities by gender and race originating in the doctor-patient interaction. Willingness to undergo surgery declines steeply after the age of retirement, at the time some eligible patients may lower their expectations of health status achievement. There is some evidence that paid employment independently increases the likelihood of operation. The relative contribution of variations in surgical decision making to differential access across regions within countries deserves further research that controls for clinical need and patient lifestyle preferences, including retirement decisions. Evidence on this question will become increasingly relevant for service planning and policy design in societies with ageing populations.