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Year : 2022  |  Volume : 11  |  Issue : 3  |  Page : 197-202

Validation of the health-related quality of life questionnaire for adult strabismus AS-20 in the Arabic language

1 Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
2 Faculty of Medicine, King Abdulaziz University; Department of Ophthalmology, King Abdulaziz University Hospital, Jeddah, Saudi Arabia

Date of Submission26-Sep-2022
Date of Acceptance19-Oct-2022
Date of Web Publication30-Nov-2022

Correspondence Address:
Lina H Raffa
Department of Ophthalmology, King Abdulaziz University Hospital, Prince Majid Rd, Al Sulaymaniyah, Jeddah 21589
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/sjhs.sjhs_113_22

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Background: The impact of strabismus to the quality of life (QoL) in adult patients has not been assessed and explored in Arab countries. Aims: This study aims to assess the validity and reliability of the Arabic-translated adult strabismus-20 (AS-20) questionnaire in determining the impact of strabismus on health-related QoL (HRQoL) of patients. Settings and Design: A cross-sectional study on the psychosocial and functional scores collected from 161 adult patients with strabismus, diagnosed from 2011 to 2021 in King Abdulaziz University Hospital, Jeddah City. Population with no strabismus manifestation was used as the control group. Subjects and Methods: One hundred and sixty-one adult patients, with a minimum age of 18 years with manifest strabismus, were contacted via phone calls to answer the QoL questionnaire list using Arabic-translated AS-20 questionnaire. Statistical Analysis Used: A model of Alpha (Cronbach) was used to determine the reliability test of the Arabic-translated AS-20 questionnaire. A comparison of two mean scores was performed using an independent t-test or Welsch's t-test, which was only significant at < 0.05 level. Results: The overall AS-20 mean scores for male and female adults were 66.79 ± 28.2, with a total psychosocial and functional mean score of 65.70 ± 30.9 and 67.88 ± 30.8, respectively. In general, female patients have a higher mean score than male patients for all the subscale items, except item 6. The case group, involving strabismic patients, showed significantly lower AS-20 scale mean scores as compared to control (48.53 ± 25.8 vs. 83.48 ± 18.1), with mean scores of 43.85 ± 25.9 and 53.87 ± 24.8 for males and females, respectively. Moreover, excellent overall score was obtained in internal consistency (Cronbach's alpha = 0.918). Conclusions: With its excellent test-retest reliability results, the Arabic version of the AS-20 questionnaire was an applicable tool for assessing strabismus among Arabic-speaking patients. Prominent impact of strabismus on patient's HRQoL was determined by the significantly lower AS-20 scores of the patients than those of the control.

Keywords: Adult strabismus-20, Arabic, health-related quality of life, questionnaire validation, strabismus, test–retest reliability

How to cite this article:
Alamri RS, Alyousef MA, Bamardouf NO, Alharbi BA, Raffa LH. Validation of the health-related quality of life questionnaire for adult strabismus AS-20 in the Arabic language. Saudi J Health Sci 2022;11:197-202

How to cite this URL:
Alamri RS, Alyousef MA, Bamardouf NO, Alharbi BA, Raffa LH. Validation of the health-related quality of life questionnaire for adult strabismus AS-20 in the Arabic language. Saudi J Health Sci [serial online] 2022 [cited 2023 Feb 7];11:197-202. Available from: https://www.saudijhealthsci.org/text.asp?2022/11/3/197/362375

  Introduction Top

Strabismus is defined as the deviation in the eye from an object in a vertical, horizontal, or torsional manner.[1] Most strabismic patients might be experiencing mental health problems.[2] They are also more prone to suffer from social issues, including social phobia disorders, low self-esteem, interpersonal interaction difficulties, and social anxiety.[3] These scenarios can be highly attributed to how social interactions greatly affect humans' quality of life (QoL) and how facial features play an important role in people's initial perception of one another based on physical appearance. The facial symmetry can actually dictate an initial impression of wellness and attractiveness.[4],[5] However, the preconceived judgment that was based on facial appearance can affect multiple aspects of life.[6] This includes relationships, career options, job opportunities, educational prospects, and self-perception which all have been directly proportional to age and strabismus angle.[3],[4],[7],[8] Moreover, strabismus has also been noted to have a great impact on the functional aspect of patients' lives affecting their sensory fusion and binocular visual field; thus, impairing their coordination and motor performance which are both essential components of motor skills and daily functions.[9],[10] One of the strabismus-specific QoL questionnaires, known as adult strabismus (AS-20), has been recently proven to be at a higher retest reliability than any other measurement tool in multiple languages.[11],[12],[13],[14],[15],[16] The impact of strabismus on the QoL in adult patients has not been assessed and explored in Arab countries. The aim of this study is to assess the validity and reliability of the Arabic-translated AS-20 questionnaire and determine the impact of strabismus on health-related QoL (HRQoL) among adult patients in King Abdulaziz University Hospital (KAUH), Jeddah City.

  Subjects and Methods Top

Subject recruitment

A cross-sectional case–control study was conducted at Ophthalmology Department, KAUH in Jeddah. The inclusion criteria comprised patients with a minimum age of 18 years who were diagnosed with manifest strabismus. Patients who were unable to fill the questionnaire due to a lack of Arabic literacy were excluded from the study. One hundred and sixty-one patients from 2011 to 2021 were within the inclusion criteria and then contacted through phone call to get the answers for the QoL questionnaire list. The records of patients were reviewed for the strabismus type and demographic data, such as age, gender, and nationality of each patient. Thirty-three of the 161 patients were asked to answer the questionnaire in a follow-up phone call a few weeks after to evaluate test–retest reliability. Controls (n = 197) without manifest strabismus and no known ocular abnormalities were recruited.

AS-20 questionnaires

The AS-20 questionnaire is a reliable and validated 20-question-based HRQoL questionnaire assessing two major aspects namely psychosocial and functional with questions number 1–10 and 11–20, respectively. The “Yes/Always” answer was given a score of 0 while the “No/Never” answer was given a score of 100.[16] To extract definitive answers from participants, “Rarely,” “Sometimes,” and “Often” were eliminated. For a normal individual, the median overall score was 95 (85–100 range). A health-care professional and translator expert, who are fluent in both the Arabic and English languages, translated all the questionnaire items into Arabic. The resulting Arabic questionnaire was then translated into English by two more specialists who can also speak both languages fluently. To ensure the quality of the translation, the back-translated version of the questionnaire was compared to the original English version following the World Health Organization recommendations of reverse translation.[17],[18],[19]

Ethical considerations

Informed consent was obtained from the patient after the research information was given to them. Ethical approval for the study was obtained from the ethical committee of KAUH, with reference number 6408222. The tenets of Helsinki were followed in this study.

Statistical analysis

This study was analyzed using IBM SPSS version 23 (IBM Corp., Armonk, N. Y., USA) and visually presented using GraphPad Prism version 8 (GraphPad Software, Inc., San Diego, CA, USA). A simple descriptive statistic was used to define the characteristics of the study variables through a form of counts and percentages for the categorical and nominal variables while continuous variables are presented by mean and standard deviations. Reliability analysis was used with a model of Alpha (Cronbach) to study the properties of measurement scales and the items that compose the scales and the average inter-item correlation. To compare the scores which are represented by two group means, an independent t-test was used. These tests were done with the assumption of normal distribution. Otherwise, Welch's t-test was used as an alternative test. Finally, a conventional P < 0.05 was the criteria to reject the null hypothesis.

  Results Top

For the case group, the population (n = 180) includes 96 male patients (53.3%) and 84 female patients (46.7%) with the mean age of 28.92 ± 10.02 years old. A distribution of 32.6% had ocular surgery, 58.3% had muscle surgery and 10.6% had Botox injection surgery. The population includes about 20.6% with esotropia, 36.7% with exotropia, and 5.0% with vertical strabismus. Among them, 118 participants have already undergone surgery at a mean number of 1.41 ± 1.0 times, with a maximum number of five. The mean duration since the last surgery was 7.38 ± 2.9 years, and the mean age at the surgery was 24.08 ± 11.15 years old. On the other hand, the control population (n = 197) includes 25 male patients (12.7%) and 172 female patients (87.3%) with the mean age of 34.43 ± 10.99 years old.

The overall mean AS-20fn score of the total population (n = 377) was 66.79 ± 28.2, whereas the overall psychosocial and functional mean scores were 67.88 ± 30.8 and 65.70 ± 30.9, respectively. Moreover, as shown in [Figure 1], the AS-20fn mean scores per group were 48.53 ± 25.8 for the case group while 83.48 ± 18.1 for the control group. With a Cronbach's alpha and P = 0.918 and <0.001, respectively, it was determined that the AS-20 total mean score of the case group is significantly lower than of the control [Table 1]. As summarized in [Table 2], the case group has a significantly higher percentage of participants than the control who replied “Yes” for all the AS-20fn scale items (P < 0.001). However, only item 6, pertaining to having reading problems because of their eye condition, gave no significant difference between the responses of the cases and control group (P = 0.182). In general, the mean percentage of participants with a response of “Yes” among the case group was 51.5% while only 16.5% among the control group, accounting both the psychosocial and functional subscales scores. Furthermore, both the psychosocial and functional subscale scores of the case group were also significantly lower than those of the control group (P < 0.001). For the psychosocial subscale, the mean scores for case and control groups were 46.89 ± 29.8 and 87.06 ± 15.2, respectively. For the functional subscale, the mean scores for case and control groups were 50.17 ± 28.2 and 79.90 ± 26.1, respectively.
Figure 1: Difference between cases and controls according to the mean AS-20fn scores. AS: Adult strabismus

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Table 1: Comparison of overall and subscale mean score for case and control group

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Table 2: Differences between cases and controls according to their “yes” response to adult strabismus-20 functional scale

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On the other hand, the overall AS-20fn mean scores, as well as the psychosocial and functional subscale scores of case and control groups were compared depending on the gender of the participants. Among the total population (n = 377), there were total numbers of 121 male and 256 female participants. As shown in [Table 3], the total mean scores for male patients for case group (n = 96) and control group (n = 25) were 43.85 ± 25.9 and 82.40 ± 20.3, respectively. On the other hand, the total mean scores for female patients for the case group (n = 84) and control group (n = 172) were 53.87 ± 24.8 and 83.63 ± 17.8, respectively. In general, male patients have significantly lower mean scores than female patients in both the case and control groups (P < 0.001).
Table 3: Comparison of subscale mean score of different genders

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The breakdown of the overall scores to psychosocial and functional subscale scores was also presented. For the psychosocial scores, male patients of the case group gave a significantly lower mean score of 41.88 ± 30.1 than that of the control group with 82.00 ± 17.8 mean score (P < 0.001). Similarly, female patients of the case group also gave a significantly lower mean score of 52.62 ± 28.5 than that of the control group with 87.79 ± 14.7 mean score (P < 0.001). For the functional scores, it was also observed that male patients also gave a significantly lower mean score of 45.83 ± 27.7 than that of the control group with 82.80 ± 27.8 mean score (P < 0.001). Similarly, female patients of the case group also gave a significantly lower mean score of 55.12 ± 28.0 than that of the control group with 79.48 ± 25.9 mean score (P < 0.001). In general, both the psychosocial and functional mean scores of both male and female patients of the case group were significantly lower than those of the control group (P < 0.001).

On testing the reliability of the Arabic translated questionnaire, as summarized in [Table 4], excellent overall scores were obtained in both internal consistency at Cronbach's alpha value of 0.918.
Table 4: Data for reliability test

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  Discussion Top

This study has quantified the impact of strabismus on the QoL of affected individuals in comparison to those unaffected ones using the AS-20 questionnaire. Results suggested that the patients with strabismus showed a significantly lower mean AS-20 scale score compared to those in the control group, as most of the strabismus patients encountered both psychosocial and functional issues unlike those in the control group. In this study, the overall mean AS-20 score in adults with strabismus was (48.53), and the mean score in a normal nonstrabismic adult was (83.48). While in the study conducted by Sah et al., the overall mean score in a young strabismic adult was found to be (61.62) while the median score in a normal nonstrabismic person range from 85 to 100.[20],[21] Similar findings were also observed in the studies conducted in the United States and China wherein the overall score of strabismus patients was significantly lower than those of without strabismus employing a similar sample-to-control ratio.[22],[23]

The relationship in terms of psychosocial and functional aspects between strabismic and nonstrabismic individuals was also assessed. For the psychosocial aspect, it was seen that strabismic patients have significantly lower mean score of (46.89) than the nonstrabismic individuals with a mean score of (87.06) (P < 0.001). Similar for the functional aspect, strabismic patients have significantly lower mean score of (50.17) than the nonstrabismic individuals with a mean score of (79.90) (P < 0.001). Although there is no test for significant difference between the two aspects in each group, it can be observed that the mean score for psychosocial has a lower value than the functional aspect. In some related studies, it was found that there is a predominance in either functional or psychosocial aspects. In the study conducted by Wang et al., it was revealed that the functional aspect had the upper hand in contributing to decreased QoL[23] while Hatt et al.[20] stated that the effect on the psychosocial aspect was more prominent than the functional aspect. In contrast, Sah et al. revealed that both psychosocial and functional subscale scores in strabismic individuals, in general, were comparable with each other, at mean scores of (61.35) and (61.89), respectively.[21] Unlike with the related studies, multiple social, psychological, environmental, and economical reasons were not elicited in this study which can be accounted to such differences in mean results. In addition, this study was based on “Yes or No” answers to the AS-20 questionnaire, which might limit the results to two polar opposites only instead of viewing strabismus' effect on the QoL as a spectrum. Although the confirmation of such a relationship is still debatable and underway, Durnian et al. (2010)[24] have cited that a lower socioeconomic status can also be associated with lower AS-20 scores.

Results also showed that both psychosocial and functional aspects were negatively affected in both types of genders. In this study, the total mean scores of male and female patients from the case group, which were (43.85) and (53.87), respectively, were observed to be significantly lower than that of the male and female patients of the control group with mean scores of (82.40) and (83.63), respectively. It was also observed that the case group, regardless of gender, gave a general lower mean score in both subscale aspects. Furthermore, it was noticeable that female patients have an overall higher AS-20 mean score than male patients (P < 0.001). A different trend was observed in the study conducted by Sah et al.[21] wherein the mean score for females (57.68 ± 13.46) was significantly lower than that of males (65.54 ± 13.53). Durnian et al. (2010)[24] also revealed in their study that female patients scored significantly lower than of male patients on the AS-20 questionnaire. Although there is such inconsistency with the literature, the authors of these papers believe that the QoL of women will be less affected by strabismus because women are pushed by the societal pressure to be more aware about their physical appearance regarding strabismus due to the media portraying female bodies in a picture-perfect manner. In this study, females have higher scores which may justify the fact that males are less likely to seek surgical correction unlike their female counterparts.

Moreover, the comparison of mean score to the control group depending on the strabismus type is not feasible in this study because of the small sample size in each strabismus subtype. Nonetheless, related literature revealed that no particular type of strabismus is proven to possibly cause a little or worse impact in QoL.[6],[25] Such findings concurred with the study conducted in the United Kingdom, which reported equal scores between esotropic and exotropic groups of patients.[24] Moreover, Sah et al.[21] have demonstrated that esotropia has worse psychosocial and functional scores as compared to exotropia however that impact was not statistically different. In contrast, a study conducted in New York showed that strabismic faces with esotropia were judged more negatively.[6] The alignment and/or differences in the findings obtained can be justified by the fact that the AS-20 questionnaire is an assessment tool that accounts for a patient's perspective only, which is likely to be unaffected by whichever direction the eye deviates to, but rather by the adversities encountered due to the distortion of appearance and impairment of function.

During the duration of this study, some drawbacks were encountered which are needed to be addressed and identified. First, the data were collected under the circumstances of COVID-19 restrictions; thus, the interaction with patients was limited to phone calls only with a lack of face-to-face interviews which could have added a higher level of accuracy. Second, the AS-20 questionnaire was applied to compare HRQoL of strabismic patients to that of the control group. The ceiling effect resulted in a large proportion of controls achieving a high score because they were more likely to answer “No.” Consequently, this can affect the comparison of HRQoL between strabismic and normal individuals by decreasing the sensitivity. Finally, the data were restricted to a selected group that attended the clinic seeking help regarding their condition, which can negatively skew the scores and disregard strabismus patients that already had a more positive outlook and thus never visited the clinic. As a consequence, it can be predicted that there could be an overgeneralization in the scores being gathered.

On a different note, the AS-20 questionnaire has been validated in many languages such as Chinese, French, Dutch, and others[11],[13],[23] but still, to the extent of our knowledge, attempts to validate this questionnaire in Arabic was not yet done to date. In addition to that, no research has been conducted already to measure the impact of strabismus on HRQoL of adults in Saudi Arabia in comparison to a control group. This study is also focusing in quantifying the test–retest reliability and internal consistency of the AS-20 questionnaire, which was only performed and executed by few numbers of existing studies.

Despite the impacts of the strabismus on a person's vision and psychosocial well-being, strabismus surgical correction is still classified as cosmetic which renders it to be categorized as optional only. Due to this, it still stands as an obstacle in pursuing surgical correction and improving patients' QoL.[5] Although previous studies have claimed that surgical correction of strabismus significantly improves psychosocial functioning and functional deficits,[26] it is highly suggested to compare the AS-20 scores of strabismus patients before and after the strabismus repair operation to further analyze how the operation affects their QoL, which can give additional knowledge and further insights on studying the AS and QoL.

  Conclusion Top

AS-20 is a tool created to assess the HRQoL among strabismic individuals, and it was applied to compare their HRQoL to that of the control group. In conclusion, the AS-20 scores of the patients were significantly lower than those of controls, which reflect the prominent impact of strabismus to their HRQoL. Furthermore, the Arabic version of the AS-20 questionnaire showed adequate test–retest reliability which can be utilized in clinical settings for Arabic-speaking patients. For future studies, this can be helpful to bring the individual's desire to undergo surgical correction into attention and correlate that to the scores they achieved. This study, among others, proves that physicians must recognize the effect of this condition on the QoL, whether it is psychosocial or functional, and incorporate it in the decision-making of indications of surgically managing strabismus.

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Conflicts of interest

There are no conflicts of interest.

  References Top

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  [Figure 1]

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


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