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 Table of Contents  
Year : 2015  |  Volume : 59  |  Issue : 4  |  Page : 272-278  

Assessment of validity and reliability of Hindi version of geriatric oral health assessment index (GOHAI) in Indian population

1 Lecturer, Department of Public Health Dentistry, Terna Dental College, Navi Mumbai, Maharashtra, India
2 Professor, Department of Public Health Dentistry, Terna Dental College, Navi Mumbai, Maharashtra, India
3 Lecturer, Department of Public Health Dentistry, Government Dental College, Goa, India

Date of Web Publication17-Nov-2015

Correspondence Address:
Romi Jain
C-503, Intop Heights, Sector 22, Airoli - 400 708, Navi Mumbai, Maharashtra
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0019-557X.169654

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Objective: The objective of this study was to translate the Geriatric Oral Health Assessment Index (GOHAI) into the Hindi language and assess its validity and reliability for use among people in India. Materials and Methods: GOHAI was translated into the Hindi language and self-administered to 420 subjects aged 55 years or above. The measures for reliability, and concurrent, convergent, and discriminant validity were assessed. The questionnaire sought information about sociodemographic details, habits related to tobacco, dental visits, tooth brushing, and self-reported perceptions of general and oral health. Results: Cronbach's alpha (0.774) showed high internal consistency and homogeneity between items. Low GOHAI scores were associated with the perceptions of poor oral and general health, low satisfaction with oral health, and a perceived need for dental care. Respondents with high socioeconomic status were likely to have high GOHAI scores. Conclusion: The Hindi version of the GOHAI demonstrated acceptable validity and reliability, and will be an important instrument to measure oral health-related quality of life (OHRQoL) for people in this region.

Keywords: Geriatric oral health assessment index (GOHAI), oral health-related quality of life (OHRQoL), reliability, validity

How to cite this article:
Jain R, Dupare R, Chitguppi R, Basavaraj P. Assessment of validity and reliability of Hindi version of geriatric oral health assessment index (GOHAI) in Indian population. Indian J Public Health 2015;59:272-8

How to cite this URL:
Jain R, Dupare R, Chitguppi R, Basavaraj P. Assessment of validity and reliability of Hindi version of geriatric oral health assessment index (GOHAI) in Indian population. Indian J Public Health [serial online] 2015 [cited 2023 Apr 1];59:272-8. Available from:

   Introduction Top

Oral health has traditionally been defined in term of disease and illness. The contemporary definition of oral health rejects the notion that health is equivalent to the absence of physical disease. [1] The use of only clinical indicators for oral health status and treatment-needs evaluation is recognized to have serious limitations. [2] Currently, conceptual models of oral health are focused on a psychosocial perspective, qualitative measurements, and the incorporation of the patient's point of view. Perception of oral health depends upon the subject's understanding of what normal oral health is and of the specific symptoms he/she may have experienced, the cultural values, past experiences with the health care system, general health, and psychosocial well-being. [3]

Self-reported measures of the impacts of oral conditions (generic health status and disease-specific) on quality of life have increased in number rapidly in the medical literature. Specific measures of oral health-related quality of life (OHRQoL) are likely to be more sensitive than generic health status measures because oral health is perceived as a distinct dimension of overall quality of life. [4]

A variety of OHRQoL instruments have been developed during the past 20 years. Frequently used questionnaires include the Oral Health Impact Profile (OHIP), [5] the Oral Impacts on Daily Performance (OIDP), [6] and the well-established Geriatric Oral Health Assessment Index (GOHAI). [7] The use of these indicators represents one of the most detailed methods for the measurement of oral health impact on quality of life. [8] They have been used in many international cross-sectional and longitudinal studies, as well as in comparative studies in different countries, allowing valid comparisons of the concerns of the population about their oral health status, when evaluated both objectively and subjectively and based on standardized criteria. [9]

The GOHAI [7] was developed by Atchinson and Dolan in 1990 and used in North America for elderly patients. Its reliability (internal consistency) was satisfactory, and all hypotheses designed to assess construct and concurrent validity were confirmed in Swedish, [10] Malay, [11] Arabic, [12] and German [13] studies. The GOHAI is fairly compact, having only 12 items. The GOHAI was initially designed to assess the oral health of older adults but has been recently used in the African-American population of all ages in the USA. [8] The GOHAI is an index that incorporates different dimensions of oral health, and it avoids problems connected with weighing, which introduces complications and subjectivity. [14]

Before introducing an index such as GOHAI in a different population with different culture, it is essential to carry out a rigorous translation and validation process. [15] Transferring such indicators from one country to another presents problems at two levels. Direct translations may present linguistic problems because some words and phrases have no direct translation and questions conceived in the context of one language may not be understood in the same way in the other language. Further, languages exist within social and cultural frameworks that are frequently unique and some questions may therefore become different or meaningless in a different culture and location. [16]

For all these reasons, it was decided to develop a Hindi version of GOHAI for use in the Indian population. The aim of this study was to test its validity and reliability.

   Materials and Methods Top

Study population

A total of 500 people aged 55 years or more, who attended Terna Dental College, over a period of 4 months (from November 2013 to February 2014) were invited to participate in the study. Terna Dental College is a private dental college, located in the urban area of Nerul, Navi Mumbai, Maharashtra. The sample size was based on the literature available, which mentions that in assessing the reliability and validity of an index or scale, the minimum necessary sample size for coefficient alpha is commonly suggested as 300, or sometimes 500. The general view on this subject is that the sample coefficient alpha obtained from larger samples tends to produce a more accurate estimate of the population coefficient alpha. [17] Thus we decided to recruit 500 subjects for this study. Eighty subjects were excluded from the study because their questionnaire was incomplete, leaving 420 subjects to be included in the final analysis.

Ethical considerations

Ethical clearance was obtained from the Institutional Review Board and verbal consent was obtained from the participants. The questionnaire forms on which information was recorded were identified by numbers, not names.


The data were collected through a self-administered questionnaire. The questionnaire included sociodemographic characteristics such as age, gender, educational level, occupation, and income. The Kuppuswamy scale modified for 2012 was used to calculate socioeconomic status. [18] Information was also collected regarding the use of tobacco products, visits to the dentist, and tooth-brushing habits. Subjects were also asked about the perception of their general and oral health, whether they were satisfied with their dental condition, their assessment of the need of the dental treatment, pain or discomfort due to temperomandibular joint (TMJ) disorders, burning mouth sensation, the sensation of TMJ clicking, and bad oral habits such as biting objects.

   Gohai Top

The 12 items of the GOHAI assessed the dimensions of physical functions (eating, speaking, and swallowing), psychosocial functions (worry or concern about oral health, dissatisfaction with appearance, self-consciousness about oral health, avoidance of social contact because of oral problems), and pain or discomfort (use of medication to relieve pain, oral discomfort). Subjects were asked if they have always, often, sometimes, seldom, or never experienced any of those problems in the previous 3 months. Questions were worded sometimes in positive and sometimes in negative directions, to require the respondents to consider their answers. Reponses were rated on a five-point Likert scale. When the data were transferred to the computer, the responses were recoded so that the responses indicating good conditions and no problems carried the highest scores. Thus, the scale score was such that a low value indicated an oral health problem. A summary score (Add-GOHAI) ranging 12-60 was calculated for each subject, and a simple count score (SC GOHAI) was calculated by counting the number of items with responses "sometimes," "often," or "always," which shows the negative impact of oral health conditions on quality of life. In the GOHAI questionnaire, questions 3, 5, and 7 are worded positively so that "sometimes," "often," and "always" show positivity or satisfaction toward oral health condition. As we were measuring negative impact, we needed to reverse the score for these three questions. Add-GOHAI and SC GOHAI scores were used to assess the concurrent, convergent, and discriminant validity of the scale by comparing it with different variables.

The process of adapting the GOHAI index for the elderly into a Hindi version and evaluating its psychometric properties involved three main steps: Translation of the English version into Hindi, a pilot study, and a main study for validity and reliability testing. [19]

Translation process and pilot study

The GOHAI was translated into Hindi by two dentists who were fluent in both English and Hindi. The Hindi draft was then back-translated into English by two other people who were also fluent in English and Hindi. The back-translated version was then compared with the original English version to verify if the questions were properly translated. [19] All of the back-translated items were worded similarly to the original ones and were comparable in their meaning. The final Hindi version was then pilot-tested on a sample of 50 subjects, after which further minor language modifications were made.

Clinical examination

The researcher assessed the number of decayed, missing, filled, and crowned teeth. The examination was done using World Health Organization (WHO) criteria. [20] All the oral examinations were performed on the same day that the questionnaire was administered.

Data analysis

The general approach involved was assessment of the reliability of GOHAI measures and assessment of concurrent, convergent, and discriminant validity.


Cronbach's alpha was calculated to assess the degree of internal consistency and homogeneity between the items. [20],[21] For test-retest reliability, 50 participants repeated the GOHAI after 1 week. Spearman's correlation coefficient was used to measure the test-retest reliability and to measure inter-item and item-scale correlation.


Concurrent validity assessed the degree to which GOHAI scores were related to the following self-reported items: General health, oral health, need for dental care, and satisfaction with oral health status. An attempt was made to assess the ability of GOHAI to distinguish between groups of people with different responses to these self-reported items. Convergent validity was evaluated by assessing the association between GOHAI score and the objective assessment of oral health status (number of missing teeth, decayed teeth), and self-reported symptoms such as TMJ pain, burning mouth sensation, and bad breath, which have hypothesized effects on OHRQoL. Discriminant validity was evaluated by examining the association between GOHAI score and self-reported bad oral habits that were hypothesised not to be associated with OHRQoL. [21],[22]

Statistical Package for the Social Sciences (SPSS version 17 Inc., Chicago, IL, USA) was used to analyze the data. Frequency distributions were produced. Medians, mean, and standard deviations (SDs) of the dependent variables (Add-GOHAI and SC GOHAI scores) were estimated and compared among different groups using the Mann-Whitney U test or the Kruskal-Wallis test as appropriate. Spearman's correlation coefficient was used to measure item-scale correlation. A P value of <0.05 was considered statistically significant.

   Results Top

Participants' characteristics

The total sample consisted of 420 participants, among whom 257 (61.2%) were males and 163 (38.8%) were females. The participants' ages ranged 55-84 years. Around 45% of the study population belonged to the upper lower socioeconomic class. Only 1.7% of the participants reported that they had excellent oral health, while more than half of the subjects perceived themselves to be in need of dental treatment.


For assessing data on the reliability of the Hindi version of GOHAI, Cronbach's alpha (0.77) showed a high degree of internal consistency and homogeneity between items. Inter-item and item-scale correlations varied between 0.740 and 0.811. Test-retest reliability was assessed by repeating the administrations of GOHAI to 50 participants. For the 12 items, the weighted kappa coefficient varied from 0.49 to 0.80, with a Spearman correlation coefficient of 0.82 between two successive GOHAI scores.


Concurrent validity was evaluated by examining the correlation between self-perceived general and oral health status and two GOHAI summary scores [Table 1]. Add-GOHAI scores decreased with poorer perceived general and oral health. As self-reported general and oral health decreased, SC scores (number of negative impacts) increased, indicating poor health and OHRQoL. Furthermore, people who perceived themselves as needing dental care and those who were not satisfied with their oral health status had significantly lower mean Add-GOHAI scores and higher SC GOHAI scores, indicating poorer OHRQoL.
Table 1: Concurrent validity: Correlation between self-reported general and oral health and the geriatric oral health assessment index (GOHAI) scores

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Convergent validity

Lower Add-GOHAI scores were associated with self-reported TMJ pain, burning mouth sensation, and bad breath, a finding that supports convergent validity [Table 2]. Participants who had one or more missing or decayed teeth had lower Add-GOHAI scores than those who had no missing or decayed teeth.
Table 2: Convergent validity: Difference in the mean scores of GOHAI (Add-GOHAI and SC GOHAI) according to different health-related questions and objective assessment of oral health

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Discriminant validity

It was evaluated by examining the association between GOHAI scores and self-reported bad oral habits, which were hypothesized not to be notably associated with OHRQoL and thus have no effect on the GOHAI scores. [Table 3] shows that there was no statistically significant difference in GOHAI scores between those who reported bad oral habits and those who did not. Moreover, GOHAI could not discriminate between participants according to the number of filled or crowned teeth.
Table 3: Discriminate validity: Difference in the mean scores of GOHAI (Add-GOHAI and SC GOHAI) according to variables that have no predicted effect on OHRQoL

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GOHAI scores were also studied among groups known to have different levels of health. Those belonging to low socioeconomic status had significantly lower Add-GOHAI and higher SC GOHAI scores. GOHAI discriminated between the subjects according to tooth brushing and visits to the dentist. Those who regularly brushed their teeth and visited a dentist had higher Add-GOHAI scores than others [Table 4].
Table 4: Association between the variables with predicted effect on OHRQoL and GOHAI scores

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   Discussion Top

This study examined the validity and reliability of the Hindi version of GOHAI in a selected group of people in Mumbai, Maharashtra. The GOHAI, which was originally developed and tested among well-educated, elderly Americans, [7] has also been demonstrated to be suitable for geriatric poorly educated populations. [8] Hindi is official language of the Union Government of the Republic of India. The population of Mumbai is multiethnic; hence, language use varies not only across different areas but also among the different ethnic groups. Due to the cultural diversity, there was much deliberation over the best way to express the GOHAI items in Hindi. This necessitated pretests of the translations.

Problems of validity stemming from cultural or language differences appear to be more complex, and populations with different cultural backgrounds may respond differently to the same GOHAI items. Thus, it is important that the GOHAI be tested in diverse populations in terms of culture, language, and geography. In this study, the first step consisted of using a standardized translation process. [19] Translation and back-translation were conducted to ensure the accuracy and interpretability of the questions. This allowed the creation of a Hindi version that exhibited satisfactory psychometric properties.

As did Locker et al., [23] we found that GOHAI was very successful at detecting oral disorders, with a few participants having a very high score of 55-57. This is because GOHAI places great emphasis on functional limitations and pain or discomfort, which are more immediate and more common outcomes of oral disorders in the elderly population.

The item measuring problems with the ability to swallow comfortably was originally developed to measure the problems that people with xerostomia might encounter. Xerostomia is more common in older adults, which is evident in this study from the fact that a higher proportion of the study population reported having difficulty in swallowing. Similar results were not obtained in a study done in France among 18-45-year-old individuals. [16] This might be due to the younger age group involved in this study.

Socioeconomic data suggest that more than half of the sample belonged to the upper lower class. Self-rating of oral health was particularly poor and perception of dental care needs was high, indicating a substantial negative impact of oral conditions. This is in accordance with previous findings showing that populations with lower socioeconomic status experienced a greater negative impact of oral conditions on functioning and well-being. [24] The perception of oral health and the level of acceptance of oral conditions may vary according to the country and the socioeconomic status, irrespective of the objective dental status. [12],[25]

The results showed that the Hindi version of GOHAI exhibits satisfactory psychometric properties. The analysis reported that the Hindi GOHAI demonstrates good internal consistency. The Cronbach's alpha coefficient was similar to the values obtained in previous surveys. [7],[23],[24],[25] Results concerning stability indicated good reproducibility concerning the global score of GOHAI (Spearman correlation coefficient r = 0.82), as in the Chinese version where 47 elderly persons were interviewed after 1 week. [16],[25] Calabrese et al.[26] obtained a lower score (r = 0.61) from 23 older adults. In this study, subjects filled in the GOHAI administered by a dentist for the first time and 8 weeks later by a physician. A longer period between the two administrations and a change in way the questionnaire was administered between the two sections might explain this lower correlation coefficient.

The concurrent validity of the Hindi version of the GOHAI was comparable to that of the original English version. [7] Analysis demonstrated the expected associations between the GOHAI scores and the reported oral and general health status, perceived need for dental treatment, and self-satisfaction with oral health. The lower Add-GOHAI scores were associated with poor perceived oral and general health, need for dental care, and low satisfaction with oral health.

Regarding convergent validity, this study supported others [5],[12] in showing that people with TMJ pain, burning mouth sensation, self-reported bad breath had lower Add-GOHAI scores than those who did not have these symptoms. Bad oral habits did not have any significant effect on the GOHAI scores. However, socioeconomic status was another factor that influenced the GOHAI scores. [12],[27],[28]

This study found a significant relationship between the GOHAI and certain clinical measures, including numbers of decayed and missing teeth. However, associations between the GOHAI scores and the number of filled or crowned teeth were not significant. Missing and decayed teeth affect eating, esthetics, and speech, and cause pain and discomfort. On the other hand, fillings and crowns are designed to restore as much of the lost functions and esthetics as possible, accounting for the fact that those with filled or crowned teeth did not score significantly worse on the GOHAI than on others.

   Conclusion Top

In conclusion, the Hindi translation of the GOHAI demonstrated acceptable validity and reliability when used for people in Mumbai, India. It could therefore be a valuable instrument for measuring ORHQoL for people in this region. Further research is needed to determine the stability of GOHAI over different time periods and to examine it as a tool to evaluate dental treatment outcomes in Indian populations.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

World Health Organization. Definition of Health. Available from: who/en/definition.html. [Last accessed on 2013 Sep 8].   Back to cited text no. 1
Locker D. Concepts of oral health, disease and the quality of life. In: Slade G, editor. Measuring Oral Health and Quality of Life. Proceedings of the 4 th Conference of the Californian Dental Association, 3 rd February 1996. Los Angeles, Chapel Hill, USA: University of North Carolina; 1997. p. 11-24.  Back to cited text no. 2
Cruz GD, Galvis DL, Kim M, Le-Geros RZ, Barrow SY, Tavares M, et al. Self-perceived oral health among three subgroups of Asian-Americans in New York City: A preliminary study. Community Dent Oral Epidemiol 2001;29:99-106.  Back to cited text no. 3
Broder HL, Slade G, Caine R, Reisine S. Percieved impact of oral health conditions among minority adolescents. J Public Health Dent 2000;60:189-92.   Back to cited text no. 4
Slade GD, Spencer AJ. Development and evaluation of the Oral Health Impact Profile. Community Dent Health 1994;11:3-11.   Back to cited text no. 5
Adulyanon S, Sheiham A. Oral impacts on daily performances. In: Slade G, editor. Measuring Oral Health and Quality of Life. Proceedings of the 4 th Conference of the Californian Dental Association, 3 rd February 1996. Los Angeles, Chapel Hill, USA: University of North Carolina; 1997. p. 151-60.   Back to cited text no. 6
Atchinson KA, Dolan TA. Development of the Geriatric Oral Health Assessment Index. J Dent Educ 1990;54:680-6.   Back to cited text no. 7
Atchinson KA, Der-Martirosian C, Gift H. Components of self-reported oral health and general health in racial and ethnic groups. J Public Health Dent 1998;58:301-8.   Back to cited text no. 8
Grath CM, Bedi R, Gilthorpe MS. Oral health related quality of life - views of the public in the United Kingdom. Community Dent Health 2000;17:3-7.  Back to cited text no. 9
Hägglin C, Berggren U, Lundgren J. A Swedish version of the GOHAI index. Psychometric properties and validation. Swed Dent J 2005;29:113-24.  Back to cited text no. 10
Othman WN, Muttalib KA, Bakri R, Doss JG, Jaafar N, Salleh NC, et al. Validation of the Geriatric Oral Health Assessment Index (GOHAI) in the Malay Language. J Public Health Dent 2006;66:199-204.   Back to cited text no. 11
Daradkeh S, Khader YS. Translation and validation of the Arabic version of the Geriatric Oral Health Assessment Index. J Oral Sci 2008;50:453-9.  Back to cited text no. 12
Hassel AJ, Rolko C, Koke U, Leisen J, Rammelsberg P. A German version of the GOHAI. Community Dent Oral Epidemiol 2008;36:34-42.  Back to cited text no. 13
Allen PF, Locker D. Do item weights matter? An assessment using the oral health impact profile. Community Dental Health 1997;14:133-8.  Back to cited text no. 14
Murariu A, Hanganu C, Bobu L. Evaluation of the reliability of the Geriatric Oral Health Assessment Index (GOHAI) in institutionalised elderly in Romania: A pilot study. Oral Health and Dental Management in the Black Sea Countries 2010;9:11-5.  Back to cited text no. 15
Tubert-Jeannin S, Riordan PJ, Morel-Papernot A, Porcheray S, Saby-Collet S. Validation of an oral health quality of life index (GOHAI) in France. Community Dent Oral Epidemiol 2003;31:275-84.  Back to cited text no. 16
Charter RA. Sample size requirements for precise estimates of reliability, generalizability, and validity coefficients. J Clin Exp Neuropsychol 1999;21:559-66.  Back to cited text no. 17
Kumar BP, Dudala SR, Rao AR. Kuppuswamy's socio-economic status scale - a revision of economic parameter for 2012. International Journal of Research and Development of Health 2013;1:2-4.  Back to cited text no. 18
Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of the health-related quality of life measures: Literature review and proposed guidelines. J Clin Epidemiol 1993;46:1417-32.  Back to cited text no. 19
World Health Organization. Oral Health Surveys, Indices and Methods for Measurement of Dental Diseases. 4 th ed. Geneva: World Health Organization (WHO); 1997. p. 21-51.  Back to cited text no. 20
Croanbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika 1951;16:297-334.  Back to cited text no. 21
John MT, Patrick DL, Slade GD. The German version of the Oral Health Impact Profile--translation and psychometric properties. Eur J Oral Sci 2002;110:425-33.  Back to cited text no. 22
Locker D, Matear D, Stephen M, Lawrence H, Payne B. Comparison of the GOHAI and OHIP-14 as measures of the oral health-related quality of life of the elderly. Community Dent Oral Epidemiol 2001;29:373-81.   Back to cited text no. 23
Kressin NR, Atchison KA, Miller DR. Comparing the impact of oral diseases in two populations of older adults: Application of the geriatric oral health assessment index. J Public Health Dent 1997;57:224-32.  Back to cited text no. 24
Wong MC, Liu JK, Lo EC. Translation and validation of the Chinese version of GOHAI. J Public Health Dent 2002;62: 78-83.  Back to cited text no. 25
Calabrese JM, Friedman PK, Rose LM, Jones JA. Using the GOHAI to assess oral health status of frail homebound elders: Reliability, sensitivity, and specificity. Spec Care Dentist 1999;19:214-9.   Back to cited text no. 26
Atchinson KA. The general oral health assessment index. In: Slade GD, editor. Measuring Oral Health and Quality Of Life. Chapel Hill: University of North Carolina; 1997. p. 79-80.   Back to cited text no. 27
Allen PF. Assessment of oral health related quality of life. Health Qual Life Outcomes 2003;1:40.  Back to cited text no. 28


  [Table 1], [Table 2], [Table 3], [Table 4]

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