Oral health status and associated lifestyle behaviors in a sample of Iranian adults: an exploratory household survey

This cross-sectional study focused on adults aged 18–65 y who were recruited between May and October 2016 in Tabriz. A population-based household survey was conducted to recruit a sample of adults from the community. The eligibility criteria were as follows: a) living in the study area and being at home at the time of data collection and (b) not having a diagnosis of mental or cognitive disorders. Written informed consent was obtained from each participant.

The population of Tabriz was estimated to be 980,000 (aged 18–65 y) in 2016 [16]. To estimate the oral health status of 50% (edentulous) of the population, according to the study [9] a likely sample proportion was considered 50%, then, with a 95% confidence, an error of 1.8% and finite population number (980,000), the sample size was estimated (n = 2956). We rounded it to 3000 in practice. For sampling, the study population was sampled using a multi-stage cluster sampling design [17]. In the first sampling stage, the city was divided into four areas (West North, West South, East North, and East south) based on socio-economic status. In the next stage, one health care centers (HCC) was randomly selected from each area (in total four HCCs from 16 HCCs). Because all people’s health records were available in the HCCs, they are used in the sampling as first sampling units. In the next stage, 25% of street blocks in the area of the selected four HCCs were randomly selected. Determined sample size (3000 persons) was proportionally divided into four area. For each block, every 11th household in the block was then contacted, and the suitability of the household members for inclusion in the study was assessed. Finally, in each household, eligible individuals were asked to participate in the study. In total, 690 people refused to participate in the study. Sampling in the blocks was continued until the required sample size specified for that block was reached. Four trained researchers conducted the interviews. Interviewers were public health students working as public health researchers and having at least 2 years of experience as an interviewer in survey-based health researches. They received three 90- min training sessions on successful performance of completing the study questionnaire. Their first ten interviews were qualitatively evaluated by 4 experienced researchers, to guarantee the quality of the interviews. In total, 2310 respondents completed the survey (a 77% response rate).

The WHO’s OHQ for adults was used for measuring the oral health status and oral health behaviors of the participants [17]. The WHO’s OHQ consists of 16 variables. Four questions are used to assess oral health status: (a) self-reported number of teeth present (0 = no natural teeth, 1 = 1–9 natural teeth, 2 = 10–19 natural teeth, and 3 = 20 natural teeth or more),; (b) experience of oral/dental pain/discomfort (yes/no); (c) wearing of removable dentures (partial/full upper/full lower; yes/no); and (d) self-assessment of the status of teeth and gums (ranging from 1 = excellent to 6 = very poor). Three items are used to assess oral health related behaviors: (a) frequency of perform oral hygiene (ranging from 1 = never to 6 = once a day); (b) use of aids/tools for oral hygiene (e.g., toothbrush, wooden toothpick, dental floss; yes/no); and (c) use of a fluoride- or nonfluoride toothpaste (yes/no). Two questions are related to the frequency of dental visits, with scores ranging from 1 (less than 6 mo ago) to 5 (5 y ago or longer), and the reasons for the dental visit(s) (e.g. consultation/advice, treatment/follow-up treatment, and dental or oral pain/discomfort). One question assesses reduced quality of life (QoL) due to 12 oral problems (e.g., difficulty biting or chewing food), with the responses scored as 0 = don’t know, 1 = no, 2 = sometimes, 3 = fairly often, and 4 = very often. One question examines the consumption of sugary foods (e.g., biscuits and cream cakes) and drinks (e.g., tea with sugar) and fresh fruit consumption, with the answers scored as follows: 1 = never/seldom, 2 = several times a month, 3 = once a week, 4 = several times a week, 5 = every day, and 6 = several times a day. One item assesses tobacco use (cigarettes, pipe, cigar, snuff, and tobacco chewing) and frequency (1 = never/seldom, 2 = several times a month, 3 = once a week, 4 = several times a week, 5 = every day, and 6 = several times a day). The last question assesses the consumption of alcohol (usually the number of drinks per day) during the past 30 d (ranging from 0 = less than 1 drink to 5 = 5 or more drinks). The remaining questions relate to the socio-demographic characteristics of the sample in terms of age (18–35, 36–50, and 51–65 y) and sex (male or female).

The validity and reliability of the WHO’s OHQ was assessed based on standardized cross-cultural translation guidelines [18]. The English version of the WHO’s OHQ was translated into Persian. Two native Persian translators unrelated to the study translated the OHQ. Any disputes were resolved by consensus.. Two professional translators then back translated the OHQ from Persian to English. The translators and researchers checked and agreed on the final Persian version. Content validity was determined in a pilot study of 20 individuals [19]. Following feedback on the scale, changes were made to the wording of some items. The Persian version of the WHO’s OHQ was then evaluated by an expert panel (three health educationists and two dentists).

The mean age (SD) of the 2310 participants was 41.6 (23.4) y. Males accounted for 48.8% of the study population. In the sample, 187 (8.1%) participants were edentulous, and 152 (20.7%) of these participants were aged 51–65 y. In addition, 72.3% of the participants were dentate (i.e. 20 or more teeth). The rate was 92.7% for adults aged 18–35 y, 71.3% for adults aged 36–50 y, and 49.4% for adults aged 51–65 y.

In the study, 61.2% of all participants reported experiencing dental and oral pain or discomfort in the previous 12 mo. Table 1 presents an overview of the oral health status of the participants in the different age groups (18–35 y, 36–50 y, and 51–65 y). The results revealed significant between-group differences, with those aged 18–35 y (71.2%) reporting significantly more dental/oral pain or discomfort as compared with that of the individuals aged 36–50 y (55.8%) and 51–65 y (54.8%). In total, 359 participants (15.5%) had a removable partial denture, of whom 9% were aged 18–35 y, 16.6% were aged 36–50 y, and 21.8% were aged 51–65 y.

The tooth brushing and cleaning habits of the three age groups are shown in Table 2. About one-third of the participants reported that they did not brush their teeth daily (23% in the 18- to 35 y -old age group, 35.9% in the 36- to 50 y-old age group, and 44.6% in the 51- to 65 y-old age group). In terms of tooth cleaning habits, 62% reported using a toothbrush, 24% reported using dental floss, and 62% reported using toothpaste.

Table 3 provides information on dental care visits among the three age groups and the reasons for these visits. In the study, 39.4, 34.1, and 26.6% of adults aged 18–35 y, 36–50 y, and 51–65 y, respectively, had visited a dentist less than 6 mo. The most frequent reason (50.9%) for visiting the dentist was dental or oral pain or discomfort.

Table 4 provides an overview of the oral health problems of the study population during the last year. The most frequent oral health issues reported by adults aged 18–35 y were cosmetic concerns related to the appearance of teeth. In contrast, the most frequent oral health problem among adults aged 36–50 y and 51–65 y was mastication difficulty (43.5 and 54%, respectively).

Information on lifestyle behaviors, including dietary habits (e.g., the consumption of fresh fruit, sweets [biscuits and cakes], and sugary drinks) and tobacco and alcohol consumption, is provided in Table 5. Only 5.7% of the participants consumed fresh fruits several times a day, and 85% of the participants consumed fresh fruits several times a week. About one-third (35%) of the participants consumed biscuits, 57.1% consumed cakes, 38% consumed jam or honey every day, and half of them consumed tea with sugar each day. In the sample, 88% of the participants reported never or seldom smoking, and 6% reported consuming alcohol several times a week.