The present study aimed to perform a cross-cultural adaptation of the short version of the DHEQ-15 instrument. This version has 15 questions. It is of utmost importance that, before being widely used, questionnaires are adapted to the cultural characteristics of a target population. DHEQ-15 is self-administered and is related mainly to perceived dentine hypersensitivity (DH).
Epidemiological data on DH have demonstrated a wide range of prevalence estimates, depending on the DH diagnosis criteria and where the study was performed. Population-representative studies on DH are scarce. One of the only representative studies on the topic was performed by Costa et al. 3.
In this study, clinical evaluation of dentine hypersensitivity was performed via air blasting and probing. The prevalence estimates were 33.4% and 34.2% for air blast and probing, respectively. This indicates that DH has the potential to impact 1 in every three persons. One of the reasons for the scarcity of representative studies on this topic is the high cost and logistic difficulties. In addition, studies using clinical diagnosis are important. However, they lack the perception of the individuals, which is considered a “true outcome” in healthcare 6.
Therefore, using patient-centered outcome measures has become a valuable way of verifying the occurrence of health events. In this sense, questionnaires have been widely used. In the DH, one instrument was developed and validated in the United Kingdom 1,7. This questionnaire included 35 questions in 5 different domains. The same research group also proposed a short version of the questionnaire, with 15 questions named the DHEQ-15 4. The short version is less time-consuming and, therefore, more accessible to apply, especially in large groups of individuals/populations. The HDEQ-15 has been cross-culturally adapted and validated for use in Brazilian Portuguese, Chinese, and Arabic 8–10(REFS) populations. Therefore, it is recommended that a Spanish version of the instrument be adapted, mainly since Spanish is widely spoken worldwide. With the development of self-administered questionnaires, there is a better possibility of assessing the prevalence and impacts of DH, which are currently unavailable.
The process adopted in the present study involved two steps: (i) First, we translated and cross-culturalized the instrument, and (ii) we assessed the internal consistency of the survey. According to international recommendations 5 for cross-cultural adaptations of questionnaires, the instrument was translated into Spanish and back-translated. After the translation and back-translation processes, the English versions were compared, and the results revealed that the content was adequate since no substantial differences were observed between the original and the back-translated versions. A preliminary Spanish version was obtained and submitted to a pilot study with 20 individuals who answered the questionnaire and provided their opinions about the comprehensiveness of the instrument. Any possible difficulties were discussed in this focus group, and the final version was approved. In the pilot exercise, no significant changes were needed.
With the final Spanish version approved, a cross-sectional study was designed for outpatients of the University of Buenos Aires School of Dentistry. Individuals seeking dental care for multiple reasons at school were included; however, answers to the questionnaire were given before any contact with dental examinations in the facility to avoid bias from the clinical diagnosis.
A total of 2,530 individuals were included in the study, approximately 1/3 of whom were males. This is in accordance with the percentage of males seeking care in the School of Dentistry and the lower percentage of males seeking dental care and participation rates in dental studies. The participants' mean age was approximately 34 years, which is the peak possible age for DH 11. It is noteworthy that the inclusion of 2,530 individuals is considered a robust number in oral epidemiology.
In the present cross-sectional study, we also evaluated an “additional question” related to self-perception of overall oral health. This question is recommended for validated versions of the DHEQ-15. The results demonstrated that 6.1% of the participants perceived their oral health as “excellent”. This point was further used as an independent variable to establish the cutoff point for the questionnaire.
Interestingly, there was a moderate-high correlation between perceived oral health and total DHEQ-15 score. Figure 2 shows that the worse the patient’s perceived overall oral health was, the greater the total DHEQ-15 score. These findings support the use of additional questions as an independent variable at the cutoff point of the questionnaire. Interestingly, the total DHEQ-15 score was associated with the overall health score. In the total sample of the present study, a mean total score of 50.5 was obtained. This short version of the scale ranges from 15 to 105 points. This is related to the fact that we used a 7-point Likert scale, in which 1 was the lowest possible score.
The internal consistency of the Spanish version of the DHEQ-15 reached a Cronbach’s alpha of .961. This value demonstrates that the questionnaire has an excellent level of internal validity since values >.700 are widely accepted as adequate 12. The other cross-cultural adaptations of the DHEQ-15 also presented similar internal consistency values 8–10.
In addition to the overall Cronbach’s alpha, we decided to suppress each of the 15 questions stepwise. This approach would allow us to understand any question that would consistently modify the results of the total score. The suppression of each of the questions did not substantially modify the Cronbach’s alpha of the instrument since the lowest Cronbach’s alpha obtained was .957, with the suppression of either question 7 or question 8.
We also designed an ROC curve to establish an adequate possible cutoff point for the score. We dichotomized the sample using "excellent" perceived overall oral health. Hence, the best cutoff point for higher sensitivity and specificity was 73. The area under the curve was calculated and found to be 0.900, which is considered adequate because of the combination of sensitivity and specificity. With these results, the Spanish version of the DHEQ-15 has good validity.
The present study has several inherent strengths and limitations. First, clinical examination was performed in only 10% of the sample (even though the questionnaire aimed to detect self-perceived DH). A nonrepresentative sample is also a limitation, especially since they seek dental care. Additionally, it should be highlighted that no longitudinal approach was used. Among the study's strengths, the number of included individuals should be highlighted, and a good level of validity should be considered.
Within this cross-cultural adaptation of the DHEQ-15, the proposed Spanish version is suitable for Spanish-speaking populations and reveals good consistency and internal validity.