The SOHO-5 consists of a child self-report and a parental report of the child’s oral health history. Both versions contain 7 items. For the child version, the report refers to difficulties eating, drinking, speaking, playing, sleeping, smiling (due to pain) and smiling (due to appearance). The answers are reported using a 3-point scale (no = 0, a little = 1 and a lot = 2) aided by an explanation card with appropriate faces. The items in the parental version include difficulty eating, difficulty playing, difficulty speaking, difficulty sleeping, avoiding smiling due to pain, avoiding smiling due to appearance and affected self-confidence. The answering options follow a 5-point scale (no = 0, a little = 1, moderate = 2, a lot = 3 and a great deal = 4). A response of “Don’t know” was not used in the self-administered parental version, as we opted for an interview-administered questionnaire. The SOHO-5 scores are calculated as the sum of response codes. A higher score denotes a greater degree of oral impacts on the children’s quality of life.
Translation and cross-cultural adaptation
The SOHO-5 was translated and adapted according to published standard guidelines [18–21]. Two translations into Portuguese were made by two native Portuguese translators. A revision panel evaluated the translations and determined the conceptual and item equivalence. The consensus-translated version was pilot tested on twenty 5- to 6-year-old children and their parents. The panel developed a pilot version, which was translated back into English by two bilingual translators. The back-translated English consensus version was compared with the original English version to determine semantic equivalence.
Finally, the draft Brazilian version was pilot tested for a second time on a different convenience sample of twenty 5- to 6-year-old children and their parents. There were no changes regarding new suggestions or difficulties of comprehension, and the panel approved the final Brazilian Version of the SOHO-5.
Assessment of validity and reliability
Data were collected from interviews with 193 5- to 6-year-old children and their parents, who were recruited from a paediatric dental screening program at the Faculty of Dentistry, University of São Paulo (USP). Children aged 1–9 years living in São Paulo city were eligible to participate in the screening programme. Children that had not received dental treatment in the last three months, had no systemic diseases and lived with their parents were eligible for inclusion. The study was approved by the USP Ethics Committee in Research, and the parents signed informed consent forms.
The child and one of the parents completed the SOHO-5 in face-to-face independent interviews. The interviews were conducted on the same day prior to the clinical examinations by four trained interviewers who were blind to the clinical findings. The children’s oral examinations referred to dental caries according to standard widely applied clinical criteria  and were conducted by two paediatric dentistry specialists who were calibrated prior to data collection (Kappa: 0.92 for intra- and 0.87 for inter-examiner reliability).
The children’s and parental questionnaires both contained global rating questions. For the children’s questionnaires, the following ratings were included: satisfaction with oral health (‘How happy are you with your teeth?; not happy = 2, a little happy = 1 and very happy = 0’) and presence of dental cavities (‘Do you have any holes in your teeth?; No = 0, Yes = 1’). For the parental questionnaires, the following ratings were included: proxy-rated oral health (‘How would you rate your child’s dental health?; excellent = 0, very good = 1, good = 2, fair = 3, poor = 4’), satisfaction with child’s oral health (‘How happy are you with your child’s dental health?; very happy = 0 to very unhappy = 4’), the child’s overall well-being (‘Do you think the overall well-being of your child is affected by the conditions of their teeth?; not at all = 0 to a great deal = 4’), and the child’s perceived dental treatment needs (‘Do you think your child needs any dental treatment because of the state (holes in teeth or pain) of his/her teeth?; no = 0, Yes = 1’).
Internal consistency was assessed using Cronbach's alpha for the total score and the item-total score correlations. The test-retest reliability was assessed by calculating the intraclass correlation coefficient (ICC) for the SOHO-5 score using the data from 159 children and their parents who were interviewed for a second time 7–14 days after the first interview by the same interviewers. We tested construct validity through associations between the SOHO-5 scores and the global ratings using Spearman's correlation coefficients. Discriminant validity compared the SOHO-5 scores between the children with a history of caries and the children without a history of caries (dmft > 0 vs. dmft = 0) using Mann–Whitney tests.