EXISTENCIA DE LOS HECHOS

This section contains a discussion about each selected variable and the reason(s) why such variables were or were not eliminated from further analysis.

Setting

This thesis proposed a different setting than that proposed by MINSAL: the application of FV in primary care appointments during well-child check-ups. Despite the fact that such an alternative is relatively new in the Chilean context, the use of well-child check-ups to perform activities related with dentistry is not new, either to deliver oral health education (Hallas et al., 2011) or to perform FV application (Achembong et al., 2014).

Considering that MINSAL currently promotes the use of such check-ups to deliver oral health education by nurses and physicians (MINSAL, 2013d), it is perfectly logical to think about extending the role of well-child check-ups in caries prevention.

Human resources (applicator)

Several repetitions of health interventions were detected in both settings, most of them were related to the variable applicator. The elimination of most of these health interventions from further analysis was due to lack of evidence about the difference in effectiveness between the personnel who apply the varnish, especially between dentists and dental auxiliary personnel (Dyer et al., 2014). Although FV is applied by non-dental professionals in others countries (Hendrix et al., 2013), almost no evidence exists about their relative effectiveness compared with dentists undertaking the application. Some authors have reported relative effectiveness, using some ad hoc outcomes, such as the number of caries-related treatments (Pahel et al., 2011). These data suggest that performance is comparable.

Consequently, it can be concluded that the difference in the type of professional who applied the FV would be explored in a sensitivity analysis that would explore the trade-off between cost and effectiveness rather than designing different comparator arms in the decision model for each type of potential. Although there is a lack of evidence on effectiveness, this form of analysis would allow consideration of whether a difference in effectiveness, as predicted by the model, would be plausible.

The selection of variables only considered clinical aspects, meaning the clinical facet of diagnosis, i.e., screening. However, the selection of limiting factors allowed consideration of other aspects of diagnosis such as prescription and legal limitations. For example, lack of ability to prescribe FV was the most important modifiable limiting factor in both settings. Allowing other carers to prescribe allowed a further set of care health interventions to be provided.

Nevertheless, there are some legal problems with eliminating restrictions on who can prescribe as currently in some of the HIs that would not be legal, such as 120100 or 130100, as dental nurses and dental assistant are not allowed to perform a diagnosis.

Oral health education

Performing oral health education (OHE) in the PSS setting is difficult, mostly due to limited participation by parents in preschool activities. This phenomenon should not happen in the PCS setting as parents are the ones that take children to the WCP. The main problem is the lack of infrastructure that does not allow oral health examinations to be performed by dental assistants and dental nurses. Furthermore, the lack of infrastructure does not allow the dental team to be separated, as there is unlikely to be enough physical space to provide the care required.

In the PCS setting, 20 health interventions with variable education were considered feasible. This means that OHE can be done in this setting. However, given that there is no evidence about the efficacy of FV with or without oral health education (OHE) and the only variation related to education is the cost (wage/hour), further exploration of the impact of this variable using sensitivity analyses was chosen.

Screening

One important consideration detected in this study was related to the concepts of diagnosis and screening, as both are intimately related. Both concepts were defined by Ireland (2010), in the Oxford Dictionary of Dentistry, as follows:

Diagnosis

“The process of arriving at the nature of a disease or condition from consideration of the patient's signs and symptoms and when appropriate, any additional diagnostic tests such as radiographs, biopsy, and blood or saliva analysis. The diagnosis of a condition or disease often involves comparison with other conditions which produce similar signs or symptoms (differential diagnosis)”.

Screening

“The process of testing a large number of asymptomatic or apparently healthy people to separate those who may have a specific disease and would benefit from further testing from those who probably do not. Screening is usually targeted at individuals who are most at risk of the disease, such as screening heavy smokers for oral cancer. Factors which need to be taken into account to determine the appropriateness of screening include the epidemiology of the disease, efficacy and availability of treatment, safety, acceptability, cost, sensitivity, and specificity of the test. Screening for diseases that affect general health, such as diabetes and cardiovascular disease, may be undertaken within a primary dental care setting”.

According to Ireland (2010), and given that the Chilean guideline (MINSAL, 2012c) establishes that a dentist must perform a diagnosis in order to detect which children meet the criteria for application of FV, dentists would be performing the screening rather than the diagnosis. Screening helps detect those individuals with high risk of developing caries and may help prioritising the allocation of resources. But due to the complexity of caries, there is no clear method to identify those children that are likely to develop caries and, unluckily, one stronger predictor of future caries is previous experience of caries (Masood et al., 2012). So, the question is, how do we detect high-risk individuals when the goal of a programme is to avoid any experience of caries?

The fact that almost 80% percent of those with a low SES have a caries history by 6 years of age (Soto et al., 2007a) is a strong argument against individual screening. Paradoxically, the guideline of FV application (MINSAL, 2012c) established as a clinical indication for application, is that the child must be in a low SES group. This leads to questions about the sense of having a dentist just for screening when the entire population of the school would be considered as having low SES, and hence, at high risk of caries; such a question is highly related to opportunity costs.

Referral

All the health interventions related to referral were blocked because of the potential for possible over demand on the health system. It would not be reasonable to refer all children with caries because the Chilean health system does not have the capacity to treat all preschool patients with a history of caries. The treatment cost could be enormous due to the high

prevalence of caries (approximately 50% of the population aged 4 years) and, the fact that most children are very young. Such preschool children require special care and highly trained personnel as well.

Here an ethical question arises: what is the utility of determining an oral health diagnosis knowing that children will not be treated nor referred and their parents must find money to pay a private dentist? More broadly, research is also needed to answer this question.

Booking

This study showed that an important number of health interventions are blocked by difficulties related to a second visit to the school. Also, the argumentative analysis of this limiting factor demonstrated that a possible second visit in the PSS setting is hard to do because there is a low probability of catching those children that did not attend the first visit. By contrast, there were no major problems about rescheduling a visit in the PCS setting.