Derivation and computation of the Fluoride Toothpaste Affordability Ratio (FTAR)

The WHO/HAI approach uses the lowest-paid unskilled government worker’s daily wage as the threshold for a medical product treating an acute condition to be affordable. If more than one day of work is required to buy a medical product, it becomes unaffordable [21].

We developed the Fluoride Toothpaste Affordability Ratio (FTAR) to assess FT affordability. Assuming 182.5g is the recommended annual consumption of FT [23], it is an unaffordable medical product in a given country when FTAR is greater than 1 calculated with Eq 1: (1)

If FTAR≤1, purchasing FT is affordable. We assume the poorest individuals to preferentially buy the cheapest available FT in terms of price/gram.

Moreover, consumer purchasing decisions of FT are also influenced by availability, marketing and individual preferences. Therefore, data from the Euromonitor database¹⁹ providing information about the three FT brands with the largest market shares for 52 countries, 40 of which were included in our study, were considered. In this case, the FTAR was modified, and FT became an unaffordable medical product in a given country when the FTAR was greater than 1 calculated with Eq 2: (2)

Eq (1) has been applied for countries, for which data on the top-three selling FTs was unavailable from Euromonitor [24]. The FTAR for countries, for which data was available from Euromonitor, was determined according to their cheapest top-three selling FT brand, i.e., not the cheapest FT brand overall necessarily. Therefore, we considered both Eqs (1) and (2) for computing FTARs across countries.

Study design

To obtain information related to the FTAR nominator (Eq (1) for non-Euromonitor countries or Eq (2) for Euromonitor countries), a standardised protocol was developed by the WHO Oral Health Programme Office in English, Spanish and French. The protocol asked the respondents to submit pictures through mobile phones, presenting information about the ingredients, price, package size, and full product name of FT products in their country of residence (S1 File). The invited respondents were either members of the WHO Global Oral Health Network of Chief Network Dental Officers (CDO), directors of WHO Collaborative Centres, or other oral health experts, and received invitation to the study via e-mail from the WHO Global Oral Health Programme. The respondents’ pictures were received by e-mail, or a mobile messaging app, and then were saved, compiled, and processed in Microsoft Excel, to estimate the FTARs. As our study’s findings are part of the upcoming WHO Global Oral Health Report, the invited respondents were informed that their submission of pictures would contribute to this report.

The protocol targeted the cheapest available product at a common point of purchase, selected of the country-specific top-three selling FT products according to Euromonitor [24]. The point of purchase was defined as a place where families or households would usually buy their supplies. It was up to the responders’ judgment to determine the most relevant common point of purchase in their country of residence. When the top-three selling FT brands could not be identified for a specific country, the data collection targeted the cheapest FT available at a common point of purchase instead. The sample protocol for Euromonitor countries is shown in S1 File. The sample protocol for non-Euromonitor countries is shown in S2 File.

The main aim of such a design was to collect FT data from as many LMICs as possible, and from all WHO Regions, in the most convenient way possible for the invited responders. To ensure homogeneity in the computation of FTAR figures, we reported the package size of all FTs in grams; therefore, if there was no package information regarding the density of g/ml in a FT, the package size of which was originally reported in ml, we assumed a density of 1.30 g/ml to convert the figure. The data collection took place between June 2019 and September 2019.

Data entry

With respect to the FTAR denominator, we estimated the “daily wage of the lowest-paid unskilled government worker” through proxies. For most (71 of 78) sampled countries, the daily expenditures per capita of the poorest 15% of the population was the corresponding proxy. For 64 countries, we computed such a proxy by using the Households and Non-Profit Institutions Serving Households (NPISHs) Final consumption expenditure in constant USD PPP rates, the most recent population estimates, and the averages of the most recently reported shares of national income held by the poorest 10% and poorest 20% of the population [25–28]. The most recent estimates of these indicators were available for the year 2017 at the time of data entry. For seven countries (Solomon Islands, Saint Kitts and Nevis, Lesotho, Myanmar and Fiji), we computed the proxy by using the Gross National Income (GNI) in constant USD PPP rates [29], as the NPISHs Final Consumption expenditure was unavailable, the most recent population estimates and the averages of the shares of national income held by the poorest 10% and 20% of the population. We applied the GDP deflator to two of these countries (Myanmar and Solomon Islands) as their latest available GNI data were before 2017 [30].

We used the daily minimum wage, as of 2019, as an alternative proxy for seven (of 78) sampled countries (Trinidad and Tobago, Saint Kitts and Nevis, Cambodia, Central African Republic, Japan, Hong Kong SAR (China) and New Zealand), for which no national income share data were available [31]. Minimum wages reported in months (years) were converted to daily minimum wages by dividing monthly (annual) minimum wages by 30 (365). If minimum wages were reported in hours, we assumed an average working time of eight hours per day to obtain the daily figures.

With respect to the FTAR nominator, the obtained 2019 prices/g of the cheapest (top-three selling) FTs in local currency units were converted to the corresponding USD PPP rates [32], and then were adjusted to 2017 prices/g in USD PPP rates through the GDP deflator, to match the 2017 figures [30], which were the most recent available estimates for use in the computation of FTARs at the time of data analysis. When the daily minimum wage was the alternative proxy, we made no inflation adjustments, as the figures corresponded to year 2019.

Estimation of FTARs and statistical analysis

We computed the FTARs of all countries according to the extracted primary data regarding the price/g of the cheapest (top-three selling) FT, related to the nominator of the FTAR, and the estimates of the daily wage of the lowest-paid unskilled government worker, related to the denominator of the FTAR. We also estimated and discussed the corresponding FTAR descriptive statistics. Additionally, we estimated the variations in FTAR figures by different World Bank Income Groups i.e., high-income group, upper middle-income group, lower middle-income group and low-income group, through stratified descriptive statistics, to explore the potential variations in the affordability of FT around the globe. Furthermore, we estimated the variations in FTAR figures by different WHO Regions.

To confirm whether the variations in the affordability of FT across Income Groups (and WHO Regions) existed because of potential FT price variations, i.e., variations in the nominator of the FTAR, or solely due to variations in the daily wages of the lowest-paid unskilled government worker, i.e., variations in the denominator of the FTAR, we also undertook two-sample-t-tests of the difference in mean prices/g of the cheapest (top-three selling) FTs between all pairs of World Bank Income Groups and WHO Regions.

Implications of the findings

Our study aimed to evaluate the affordability of FT in as many countries as possible to capture the extent of variations in FT affordability between high-, middle- and low-income countries. Substantial differences in the affordability of FT among World Bank income groups were shown. From the perspective of the lowest-paid unskilled government worker, the annual recommended amount of the cheapest (top-three selling) FT would still be affordable for those living in high-income countries, in contrast to those in low-income countries. The picture in middle-income countries was more mixed, with FT being affordable in most upper middle-income countries, but not all (Brazil, Jordan and South Africa), and unaffordable in most lower middle-income countries. With respect to the analysis by WHO Regions, the variations in FT affordability were largely determined by the economic mix of the WHO Regions’ member states. If faced with unaffordable purchasing choices, consumers living on a low income may avoid buying FT products and hence miss out on their preventive benefits for oral health. Such findings add another aspect on inequalities in oral health and opportunities for effective self-care.

Interestingly, the earnings of the lowest-paid unskilled government worker, rather than variations in the prices per g of the cheapest (top-three selling) FTs, influenced the variability in FT affordability across countries in the sample. It can thus be concluded that current FT prices for populations in low-resource settings are too high related to their earnings. Recent investment case estimates for Burkina Faso, a low-income country, indicate that FT prices would need to be 33% lower than current market prices for a consumer to invest in oral health [33].

Study strengths and weaknesses

Compared to the previous study [22], our study provides evidence on FT affordability from a higher number of countries, covering approximately 40% of WHO member states and including a considerable number of LMICs (44). Moreover, the study’s design reduces the risk of reporting errors in the collection of the FT pricing data through the submission of participant responses via photos instead of self-completed questionnaires. This also increases the overall response rate since only a minimal amount of time during normal shopping is required to collect a response. Furthermore, our study has introduced a new dimension for estimating the FTAR across countries, that is the consideration of the availability, individual preferences, and marketing of FTs at the national level, by asking participants from 40 of 78 included countries to provide pricing information about the cheapest top-three selling FT (according to Euromonitor database [24]) in their country of residence. Finally, we consider the FTAR as a reliable measure for international comparisons of FT affordability, because it is aligned with to the widely adopted WHO/HAI approach [21].

However, four limitations exist. First, we made several approximations of the daily wage of the lowest-paid unskilled government worker to obtain the FTAR figures. For instance, the estimated FTARs of seven countries, which used daily minimum wages as a proxy for the daily wage of the lowest-paid unskilled government worker, may be different from the corresponding FTARs that would have been estimated had the daily expenditure per capita of the poorest 15% of the population data been available with appropriate income shares. Second, consumers do not tend to buy the full annual supply of FT at once; they usually buy it in smaller increments, either when a tube or sachet is empty, or when there is a special bargain at a common point of purchase. Therefore, the theoretical construct of unaffordable expenditure may not match the actual FT consumption behaviour of many individuals. Nevertheless, as this limitation was identified before the data collection process, the study’s protocol asked the responders to provide information about FTs with a package size ranging as closely as possible to 75–100 ml/g. Third, the definition of FTAR may not accurately represent the consumption behaviour of poorer economic groups. Several dependents may rely financially upon the single earning of a lowest-paid unskilled government worker, thus making the earning indirectly lower for such a worker [21]. Fourth, it is likely that regional variations in FTAR within the surveyed countries exist, either due to variations in the income of the lowest-skilled government worker or variations in the cost of the cheapest (top-3 selling) FT product; such variations were not captured in our study.

Policy recommendations for strengthening the universal affordability of FT

The study has shown that the affordability of FT needs to be addressed as a matter of public health concern at least in countries with a risk of unaffordable expenditure, mainly LMICs. Entry points for interventions, leading to lower consumer prices and better affordability, are related to government regulations that influence the prices of medical commodities, such as FT. For other medicines and medical products, equity pricing has been used, where prices are differentiated according to the country’s or population group’s income levels or purchasing power.

The World Trade Organization (WTO) suggests strategies such as generic competition, high volume production “through global or regional procurement”, the adoption of differential pricing, or the strengthening of local production “through voluntary licensing and technology transfer” as viable approaches to make essential medicines more affordable [34]. Similar strategies might be applied for FT as well, ideally aligned with national policies related to essential medicines. In controlled contexts of community, school or workplace programmes policies should be encouraged that provide FT free of charge if financially feasible, to improve the oral health outcomes of people living in socioeconomically deprived areas [35].

Fiscal measures may include the elimination or reduction of VAT for essential medicines or medical products to strengthen consumer demand [36]. Any reduction in VAT or other tariffs would be beneficial for the FT due to the regressive nature of such levies affecting poorer households more than richer households. It is important, however, that any reductions in taxes and tariffs are also passed on to the consumer rather than being used to increase the producer or distributor’s profit margins.

Finally, profit margins for toothpaste products along the production and logistics chains are significant. Packaging and marketing have a large share in production costs [37], which leads to a low-price segment of unbranded products sold by large retailers. Promoting generic competition through social marketing strategy for price reduction, however, is complex and requires a solid framework of quality assurance and standards for FT. Product quality, labelling requirements and consumer safety are matters of public health concern, including a large market share of counterfeit products in the low-price segments in many countries [38].

The WHO Director-General’s report on oral health recommends “promoting legislation to increase the affordability and accessibility of high-quality fluoride toothpaste and advocating for its recognition as an essential health product” [39]. The recent inclusion of FT in the WHO Model List of Essential Medicines [13], as well as our findings, provide a unique and pertinent opportunity to address FT affordability depending on national fiscal setting, taxation systems and regulations, and supported by additional public policy actions to ensure universal access FT.

Conclusions

Fluoride toothpaste (FT) is an essential public health product to reducing the incidence of dental caries, one of the most prevalent non-communicable diseases worldwide. Despite its wide availability for citizens across the globe, FT’s potential benefits are not fully achieved due to high prices for the poor and disadvantaged populations in many middle- and low-income countries. To ensure that everyone has access to FT, health policy options should be considered to address and improve the universal affordability of FTs, such as equity pricing, generic competition, encouragement of local production of FTs, and proper elimination or reduction of VAT for FTs.