Introduction
Risk of falling and frailty syndrome are common in old age [1]. Fear of falling is one of the common complications after falling in the elderly [2]. At first, it was thought that it occurs only because of a fall accident, but in a prospective cohort study in Japan, it was found that people without a history of falling also have a fear of falling [3]. Its destructive psychological effects can cause movement impairment and reduce activities of daily living, and the quality of life [4]. On the other hand, it is believed that the motor impairment due to the fear of falling can increase the risk of developing frailty syndrome [4]. Identification of modifiable risk factors of frailty syndrome is very important for the development of targeted interventions to prevent or reduce vulnerability in the elderly [1, 5, 6], because by early identification of the underlying factors in the initial stages, we can improve the conditions to some extent; if the syndrome progresses, it will increase the health care costs, creating a double burden on the elderly, their families, and the health system [6, 7].

Methods
This is a descriptive-analytical study with a cross-sectional design. First, six comprehensive health service centers in two areas of Bushehr city were selected by cluster sampling method. Then, 215 samples were randomly selected. The criteria for entering the study were age ≥60 years, the ability to communicate verbally in Persian, not being permanently dependent on a wheelchair, not living in care centers for a long period, no blindness or severe visual impairment, and no deafness or severe hearing loss. The tools used in this study were a demographic/clinical form, Falls Efficacy Scale International (FES-I), and Fried’s frailty scale. The FES-I was developed by Yardley et al., and its Persian version was validated by Khajavi et al. in 2012 [8, 9, 10]. In our study, Cronbach’s α coefficient for the reliability of Persian FES-I was obtained 0.954. The frailty scale is one of the most common qualitative and clinical indicators of frailty in the world, which was designed by Linda Fried [11, 12, 13]. It measures 5 criteria of exhaustion, weakness, slowness, low physical activity, and weight loss [7, 14]. To measure the relationship between the response variable and other independent variables, chi-square test was first used, and then the relationship between the variables was checked using logistic regression analysis in SPSS software, version 24.

Results
Of 215 participants (mean age=68.81±8.31), 56.7% (n=122) were female and 43.3% (n=93) were male. Based on the chi-square test results, the fear of falling was significantly higher in those with younger age, low education level, low income, those who were widower/widow, housekeeper or retired, and those with a history of falling in the last year and frailty. The fear of falling was also significantly different in terms of the number of drugs used and the number of underlying diseases (P<0.001). According to Table 1, based on the regression model without adding confounding variables (model 1), the fear of falling with moderate intensity had no significant relationship with frailty syndrome, but the fear of falling with high intensity had a significant relationship with frailty, such that the chance of having frailty syndrome in older people with high fear of falling was 17 times more than that in older people with moderate fear of falling (OR=17.4, 95% CI, 5.12%-59.12%). 


Based on the logistic regression model moderated by age, weight and height factors (model 2), the probability of having frailty syndrome in older people with high fear of falling was 10 times more than that in older people with low fear of falling (OR=10.4, 95% CI, 2.49%-43.54%). In the third regression model, the rest of confounding variables including employment status, marital status, income level, and educational level were added and the results showed that the risk of developing frailty syndrome in older people with a high fear of falling was 6 times more than that in those with low fear of falling (OR=6.37, 95% CI, 1.44%-28.08%). In the multivariate logistic analysis model to predict the frailty syndrome, the factors that were significant in the bivariate analysis and as well as gender and age were added. Omnibus Test was used to evaluate the logistic regression model, whose results (X2=121.314, P<0.001) showed that a significant prediction model was designed. Also, the Hosmer-Lemeshow test results was not significant (P=0.074), which indicates the good fit of the logistic model. In the Nagelkerke R-Squared test, it was shown that the dependent variable was predicted by the independent variables with 50% accuracy. The overall accuracy of the model was 78%. Examining the logistic regression coefficients showed that the variables of being married (0.69%), being employed (0.67%) were protective factors that could reduce the risk of suffering from frailty syndrome. The variables of using ≥3 drugs (3.8 times), having ≥3 underlying diseases (3.6 times), high fear of falling (1.4 times), and having a history of falling (3.9 times) were the factors that could increase the risk of frailty syndrome.

Conclusion
The results of this study showed a direct relationship between the fear of falling and frailty syndrome, where the elderly with high fear of falling were at a higher risk of suffering from the frailty syndrome. This is consistent with the results of Qin et al. in China [4], Esbrí-Víctor et al. in Portugal [6], and Merchant et al. in Singapore [15]. Fear of falling is influenced by several factors such as previous experience of falling, unsafe environmental conditions, low quality of life, and unhealthy lifestyle [16, 17]. The elderly people living in Bushehr city suffer from unsafe living environment, low activity due to the hot climate, and low quality of life. It is possible to prevent the occurrence or aggravation of the frailty syndrome in these people by preventing the factors that cause or intensify the fear of falling, such as reducing the use of multiple medications, preventing underlying diseases, increasing health literacy, raising the quality of life, and increasing physical activity.

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of the University of Social Welfare and Rehabilitation Sciences (Code: IR.USWR.REC.1400.159).

Funding
This research did not receive any grant from funding agencies in public, commercial or non-profit sectors.

Authors' contributions
All authors participated in the design, execution and writing of all parts of the present study.

Conflicts of interest
The authors declared no confilict of interest.

References

1. Ray M. Fear of falls and frailty: Cause or consequence or both? Journal of Aging Research And Healthcare. 2021; 4(2):1-13. [DOI:10.14302/issn.2474-7785.jarh-21-4041]
2. Rabiei MA. Evaluation of the fear of falling and related risk factors in elderly people from Hamadan, Iran: A cross sectional study. The Egyptian Journal of Geriatrics and Gerontology. 2021; 8(2):20-4. [DOI:10.21608/ejgg.2021.204174]
3. Borhaninejad V, Rashedi V, Tabe R, Delbari A, Ghasemzadeh H. [Relationship between fear of falling and physical activity in older adults (Persian). Medical Journal of Mashhad University of Medical Sciences. 2015; 58(8):446-52. [Link]
4. Gillespie S, Friedman SM. Fear of falling in new long-term care enrollees. Journal of the American Medical Directors Association. 2007; 8(5):307-13. [DOI:10.1016/j.jamda.2007.04.006] [PMID] [PMCID]
5. Makino K, Makizako H, Doi T, Tsutsumimoto K, Hotta R, Nakakubo S, et al. Impact of fear of falling and fall history on disability incidence among older adults: Prospective cohort study. International Journal of Geriatric Psychiatry. 2018; 33(4):658-62. [DOI:10.1002/gps.4837] [PMID]
6. Torkaman Gholami J, Mohamadi Shahbolaghi F, Norouzi K, Reza Soltani P. [The relationship between fear of falling and activity limitations among seniors of Ghaem Shahr City in 2013 (Persian)]. Iranian Journal of Rehabilitation Research in Nursing. 2015; 2(1):45-52. [Link]
7. Qin Y, Li J, McPhillips M, Lukkahatai N, Yu F, Li K. Association of fear of falling with frailty in community‐dwelling older adults: A cross‐sectional study. Nursing & Health Sciences. 2021; 23(2):516-24. [DOI:10.1111/nhs.12840] [PMID] [PMCID]
8. Dhar M, Kaeley N, Mahala P, Saxena V, Pathania M. The prevalence and associated risk factors of fear of fall in the elderly: A hospital-based, cross-sectional study. Cureus. 2022; 14(3). [DOI:10.7759/cureus.23479]
9. Merchant RA, Chen MZ, Wong BLL, Ng SE, Shirooka H, Lim JY, et al. Relationship between fear of falling, fear‐related activity restriction, frailty, and sarcopenia. Journal of the American Geriatrics Society. 2020; 68(11):2602-8. [DOI:10.1111/jgs.16719] [PMID]
10. Navarrete-Villanueva D, Gómez-Cabello A, Marín-Puyalto J, Moreno LA, Vicente-Rodríguez G, Casajús JA. Frailty and physical fitness in elderly people: A systematic review and meta-analysis. Sports Medicine. 2021; 51(1):143-60. [DOI:10.1007/s40279-020-01361-1] [PMID]
11. Palomo I, García F, Albala C, Wehinger S, Fuentes M, Alarcón M, et al. Characterization by gender of frailty syndrome in elderly people according to frail trait scale and fried frailty phenotype. Journal of Personalized Medicine. 2022; 12(5):712. [DOI:10.3390/jpm12050712] [PMID] [PMCID]
12. Souza Júnior EV, Silva CDS, Pirôpo US, Santos BFMD, Guedes TP, Siqueira LR, et al. Effects of sexuality on frailty and quality of life in the elderly: A cross-sectional study. Revista Brasileira de Enfermagem. 2021; ;75(1):e20210049. [DOI:10.1590/0034-7167-2021-0049] [PMID]
13. Meerkerk C, Chargi N, de Jong P, van den Bos F, de Bree R. Low skeletal muscle mass predicts frailty in elderly head and neck cancer patients. European Archives of Oto-Rhino-Laryngology. 2022; 279(2):967-77. [DOI:10.1007/s00405-021-06835-0] [PMID] [PMCID]
14. Won CW. Implications of frailty interventions from Korean frailty and aging cohort study. Aging Medicine. 2021; 4(4):247-9. [DOI:10.1002/agm2.12188] [PMID] [PMCID]
15. Silveira T, Pegorari MS, de Castro SS, Ruas G, Novais-Shimano SG, Patrizzi LJ. Association of falls, fear of falling, handgrip strength and gait speed with frailty levels in the community elderly. Medicina (Ribeirão Preto). 2015; 48(6):549-56. [DOI:10.11606/issn.2176-7262.v48i6p549-556]
16. Esbrí-Víctor M, Huedo-Rodenas I, López-Utiel M, Navarro-López JL, Martínez-Reig M, Serra-Rexach JA, et al. Frailty and fear of falling: The FISTAC study. The Journal of Frailty & Aging. 2017; 6(3):136-40. [DOI:10.14283/cw.2017.9] [PMID]
17. Fried LP, Tangen CM, Walston J, Newman AB, Hirsch C, Gottdiener J, et al. Frailty in older adults: Evidence for a phenotype. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2001; 56(3):M146-56. [DOI:10.1093/gerona/56.3.M146] [PMID]
18. Hajati S, Bastani F. [Fear of falling and its contributing factors in the elderly with the history of orthopedic surgery (Persian)]. Iran Journal of Nursing. 2019; 32(118):50-61. [DOI:10.29252/ijn.32.118.50]
19. Khajavi D. [Validation and reliability of Persian version of Fall Efficacy Scale-International (FES-I) in community-dwelling older adults (Persian)]. Iranian Journal of Ageing. 2013; 8(2):39-47. [Link]
20. Khajavi D, Farokhi A, Jaberi Moghadam AA, Kazemnejad A. [The impact of a training intervention program on fall-related psychological factors among male older adults in Arak (Persian)]. Iranian Journal of Ageing. 2014; 9(1):32-9. [Link]
21. Aghmashe R, Alavi-Naeini A, Mirzaei K, Yekaninejad M. [Relationship between dietary patterns and moderate frailty syndrome in elderly (Persian)]. Iranian Journal of Nutrition Sciences and Food Technology. 2017; 12(3):19-28. [Link]
22. Hanlon P, Fauré I, Corcoran N, Butterly E, Lewsey J, McAllister D, et al. Frailty measurement, prevalence, incidence, and clinical implications in people with diabetes: A systematic review and study-level meta-analysis. The Lancet Healthy longevity. 2020; 1(3):e106-16. [DOI:10.1016/S2666-7568(20)30014-3] [PMID]
23. Thinuan P, Siviroj P, Lerttrakarnnon P, Lorga T. Prevalence and potential predictors of frailty among community-dwelling older persons in Northern Thailand: A cross-sectional study. International Journal of Environmental Research and Public Health. 2020; 17(11):4077. [DOI:10.3390/ijerph17114077] [PMID] [PMCID]
24. Niksolat M, Zandie Z, Larijani SS, Rashedi V, Mirfakhraee H, Bahadori F, et al. The prevalence of frailty syndrome and its associated factors among elderly hospitalized in Firoozabadi Hospital. International Journal of Early Childhood Special Education. 2022; 14(3):3515-23. [Link]
25. Khalid K, Zulfaqar N, Riaz H, Jabbar M. Prevalence and risk factors of fear of fall among old age population of Lahore, Pakistan: Fear of fall among old age population. Pakistan BioMedical Journal. 2022; 5(7):36-9. [DOI:10.54393/pbmj.v5i7.559]
26. Joanny A, Zahari Z, Mohan V, Justine M. Comparison of sarcopenia indices based on fall history and level of fear of falling among community-dwelling older adults in Selangor, Malaysia. Malaysian Journal of Medicine and Health Sciences. 2022; 18(8):118-24. [Link]
27. Morowatisharifabad MA, Shakeri-Mobarakeh T, Vaezi Sharifabad AA, Bidaki R, Asgari-Shahi M, Rezaeipandari H. Fear of falling and social participation in the elderlies in Mobarakeh, Isfahan Province, Iran. Elderly Health Journal. 2017; 3(1):42-9. [Link]
28. Mohamed Hassan Saleh N, El-Gilany AH, Noshy Abd El-Aziz Mohamed H, Mahmoud Elsakhy N. Effect of matter of balance program on improving balance and reducing fear of falls among community-dwelling older adults. Egyptian Journal of Health Care. 2022; 13(1):1106-16. [Link]
29. Deepa S. Prevention of falls. Journal of The Indian Academy of Geriatrics. 2022; 18(1):1-2. [Link]