Original Article

Self-perceived health and functional status of older people: Telephone-based lifestyle survey of older adults in Tehran province

Introduction

Increasing life expectancy and the decreased fertility rate in communities has led to a significant worldwide growth in the aging population with impressive needs to health care services in recent decades.^1,2 Although longer living due to the reduced mortality is a valuable achievement of advances in health sciences, it may be accompanied with an increased prevalence of multimorbidities, disabilities, and the incremental increases in health care utilization.^3,4 Chronic non-communicable diseases are still the most common causes of death and disability in older population, particularly in low and middle income countries.^5,6 Multimorbidities not only lead to more health care costs, but also will result in poorer subjective well-being.^7,8

Iran will face a huge number of old population in near future.⁹ The aging population of Iran ( > 60 years) has increased from 6.6% in 1996 to 9.3% in 2016, and the number of old people is expected to double between 2015 and 2030.¹⁰ Therefore, meeting health care needs of the aged population is a challenging necessity for the health system.^11,12 Priority setting while allocating the resources needs a comprehensive knowledge about the health status of community dwelling older population.

Knowing the health status, including functional status, disease profile, pain, continence, and sensory status as well as self-perceived health (SPH) can be helpful for health policymakers to design appropriate care and preventive programs for older adults. Moreover, the subjective aspects of health are important in a similar vein to objective ones in the profile of active aging.¹³ SPH is a simple method for evaluating the individual’s health status. SPH is a powerful predictor of mortality and morbidity in old age, and is affected by many different factors such as physical and mental health, and cultural background.^14,15 Numerous studies have revealed an association between SPH and health outcomes, including functional limitations,¹⁶ frailty¹⁷ and mortality¹⁵ among older people. The socio-cultural structure of communities may affect the health condition of individuals.¹⁸ There is a lack of evidence regarding the perception of various dimensions of health status in low- and low-middle income countries.¹⁶

There is a scarcity of data about the health status of older adults in Iran, particularly in Tehran province. Some of these data is very crucial for policymaking, including data of independency in activity of daily living (ADL) and instrumental activity of daily living (IADL), as well as the prevalence of multimorbidity.

This study was designed to assess the epidemiologic characteristic of health condition, independency, multimorbidity, and SPH condition of the older adults in Tehran province. Tehran province is the most populous province of Iran and one-sixth of Iranian older adults are living in this province. Because of huge immigration of population, the population of Tehran province is approximately representative of Iran’s population. This study provided data about self-report health condition and history of health problems in a representative sample of community dwelling older people of Tehran province. As the health indices are significantly different between both sexes in older adults, we need the reliable data on each sex for policymaking. Although similar research is conducted in Tehran province, but the present research is unique in term of scope.¹⁹ Therefore, this study aimed to evaluate the geriatric syndrome, dependency in activities of daily living, health utilization, physical and mental health status in the mentioned population.

Material and Methods

Setting and sampling

This is a cross-sectional telephone-based survey carried out from July 2015 to February 2016. This study had a representative sample of community dwelling older adults who lived in Tehran province which has more than 13 million populations and is the most populous province in Iran encompassing 10.4% of adults aged ≥60 years old. This province has 16 counties; and Tehran metropolitan itself has 22 districts. The sampling of study is proportionated to rural and urban regions. The sampling was based on telephone numbers using a systematic random sampling for each county and each district of Tehran metropolitan. Before the random sampling, the telephone numbers of non-residential places were excluded. As the proportion of aged adults living in Tehran province is about 10% of the total general population and the expected response rate was estimated as 50%, the number of telephone was estimated 20 times greater than the sample size. In cases that there were no older adults in family or if there was an older adult unwilling to participate, the next telephone numbers were replaced to reach to a family that one of members had criteria for enrollment and agree to participate.

In order to decrease intracluster correlation between the data of the samples, in some cases that two or more older adults were living in a residential place (apartment or house), one was randomly selected.

Participants

Old adults aged ≥ 60 years who could communicate via telephone were included. Those who were excluded from the research were elderlies with moderate to severe cognitive impairment, according to state of their caregivers (which impaired his/ her daily function due to cognitive impairment), patients with end stage cancer, and bed ridden older adults. Those subjects diagnosed with dementia, but had no problem in daily functions were included in the study.

Data collection

The participants data on demographic characteristics, history of past health conditions, history of hospital admission in the last 6 months and times of admission, and continence (bowel and urine) were collected using a questionnaire approved by an expert panel. Pain assessment was performed by asking the participant about presence, location, and severity of chronic pains. The items for pain evaluation were derived from Brief Pain Inventory (BPI). Sensory status, oral health, sleep status and denture having were asked during the telephone-based interview. ADL and IADL were assessed using the Persian version of Katz’ ADL²⁰ and Lawton’s IADL.²¹ Katz’ ADL included 6 items, and a score of 12 indicates full function (each item can change from zero to 2 score) and the minimum score could be zero. The highest score of Lawton’s IADL is 8 indicating the complete independency and the minimum score is zero. SPH was evaluated using the well-known question. We assessed history of hospital admission, falls, and accidents over last six months by asking participants or one of informants. Self-reported history of health problems such as diabetes, hypertension, dyslipidemia, coronary heart disease, cerebrovascular disease, thyroid problems, peripheral vascular disease, heart failure, renal failure, liver failure, dementia, Parkinson’s, chronic obstructive pulmonary disease, cancers, infections, including pneumonia and urinary tract infections last year, and the history of aging syndromes such as delirium, pressure ulcers, urinary and feces incontinence in the last 6 months, were revealed by asking from the participants or their informants. The drug history and previous health conditions were self-reported and answered by the study participants themselves.

Trained nurses or gerontologists performed the interviews by telephone during one or two call sessions. Each interview lasted between 20 to 40 minutes. In cases of doubtful responses, interviews were performed with one of the participants’ informants.

Suffering from any type of pain, locations and severity of pain also interfering of pain with the work were detected in the interviews.

The data about lifestyle is based on a questionnaire created by researchers that was inspired by two questionnaires, HELP and Life Style Profile II, and includes questions about seven categories, including physical activity, smoking, alcohol consumption, and sleep characteristics.

The data collected through the telephone survey by the researchers were recorded in the ASP.NET MVC web application and stored in the MSSQL database.

Statistical analysis

The statistic significant were defined as P values < 0.05. All statistical tests were performed as two-way. As the prevalence rates of the conditions that we reported are population-structure related, we carried out as survey analysis with weights equal to the inverse of the sample-population ratio to address this concern. Description of the prevalence was conducted by the point estimation of frequency and 95% confidence interval. Normal distributed variables were compared using independent t test. The proportions were compared using χ2. All analysis were done using STATA package version 11.0 (Stata Statistical Software: Release 11. StataCorp LP. Package, College Station, TX, USA).

Results

In this study, 1251 aged people (54.83% were female) participated with the mean age of 67.03 ± 7.51 years. In total, 74.82% (936) of participants were married, and 96.91% of them had children. (See Table 1).

Functional status

Table 2 shows the functional status of the participants defined by the ADL (Katz) and IADL (Lawton) in different gender and age groups. More than 42.0% of the female > 80 years were totally dependent while, 42.5% of male > 80 years were totally independent by ADL. Near to 73.6% of female and 55.5% of male > 80years were dependent in 3 domain or more by IADL.

Pain

Among all the participants, 79.4% (95% CI = 79.4-79.5) mentioned that they were suffering from any pain that 87.8% (95% CI = 87.7-87.8) of women and 71% (95% CI = 70.9-71.1) of men reported to have pain at a least one organ. However, by gender, 82.7% (95% CI = 82.6-82.8) of females with older ages were experiencing pain and this portion seems to increase with age so that most age groups experiencing pains were women older than 80 years old. (91.2%; 95% CI = 91.1-791.4).

Among the participants, 26.0% (95% CI = 26.0-26.1) asserted that they suffered moderatejoint pain and 20.5% (95% CI: 20.5-20.6) of them had history of mild headache. The prevalence of sever joint pain was more common in the age-group of > 80 years old (35%; 95% CI = 34.8-35.3) (see Supplementary file 1, Table S1).

Pain effect

Among participants, 4.2% (95% CI: 4.1-4.2) of the responders stated that “their pain has extremely interfere with normal work” and 23.7% (95% CI: 23.6-23.8) stated that “quite a bit interferes with their work”, and the highest proportion of the participants; 34.7% (95% CI: 34.6-34.8) reported the pain moderately interfered with their normal work; 28.3% (95% CI: 28.2-28.3) reported the pain interference was “a little bit” and only 8.8% (95% CI: 8.8-8.9) reported that they have no pain “not at all” (See Table S2).

Self-perceived health

Only 13.01% (95% CI: 12.97-13.05) of the participants reported their perceived health reported as excellent, 59.90% (95% CI: 59.85-59.96) of the participants reported that had very good health condition, and 5.00% (95% CI: 4.97-5.02) reported as suffering bad health condition.

Balance problems

Totally, 65.4 % (95% CI: 65.4-65.5) of older adults reported that they had balance problems. The highest prevalence of balance problem was observed in women in the age-group ≥80 years (47.3%; 95% CI 47.0-47.6) (See Table S3).

Amongst the participants, 11.6% (95% CI: 11. 5-11.6) had a history of hospital admission over the last 6 months, and the age group of 70-79 years had the highest proportion of hospital admission among all age groups. The detailed information about the hospital admission times in all age groups and the disease profile of the participants are listed in Table S4.

Medical history

Totally 57.5% (95% CI: 57.4-57.5) of older adults reported that they had ≥ 3 comorbidities. The most prevalent reported health problem among the participants was osteoarthritis 46.1% (95% CI: 46.0-46.1). Moreover, 40.6% (95% CI: 40.5-40.6) of older adults had a history of hyperlipidemia (see Table S5, S6).

Using assistive instruments

Of total, 64.72% (95% CI: 64.66 – 64.77) and 8.66% (95% CI: 8.63 – 8.70) of participants were using glasses and hearing aid, respectively (see Table S7)

Teeth and eating ability

Among the participants, 60.2% (95% CI: 60.1-60.2) were using dentures. Also 90.3% (95% CI: 90.2-90.3) had intact eating ability (see Table S8).

Sleep status

Of total, 32.7% (95% CI: 32.6-32.8) had problems with sleep, 40.3% (95% CI: 40.0-40.6) female participants aged > 80 years had problem with sleep (see Table S9).

Continence

Amongst the participants, 71.5% of them (95% CI: 71.4-71.5) stated that they could completely control their urine sphincters, and 5.3% reported that was completely incontinent. In addition, 91.9% of them (95% CI: 91.9-92.0) stated that they could completely control their stool sphincter, and 3.1% reported that have fecal incontinence (see Table S10).

Discussion

This study was carried out to assess geriatric syndrome, functional status (ADL and IADL), health conditions such as pain, polypharmacy, sensory disability, incontinence, and SPH status of older adults in Tehran province. Despite the heterogeneity of older adults, it seems that with the aging of population, a poorer health situation among older adults was expected which may require more comprehensive health service packages.

Functional status

Near to two third of the participants were totally independent in terms of ADL and IADL and this rate increased with aging of the population; More than one third of ≥80 years old group, while less than one tenth of participants aged 60-69 years were dependent in ADL. In general, more than one third of the community dwelling older adults in all age groups needed some degree of helping for performing of ADL. This high proportion of dependency in this Iranian older population should be considered by the policy makers to extend elderly home care services. Furthermore, only a little more than 40% of the participants were able to do their chores in IADL independently. As the population of older adults is growing in Iran with the changes in the family structures, it is expected that the responsibility of care for older adults will be moved from family members to the formal care settings during in the near future. Although Taheri Tanjani et al reported an independency of 86% in ADL among older adults in a sample from 5 provinces of the country, as the participants of that study were somehow active members of health care centers, they may underestimate the dependency prevalence among the older adults because their participants had a better functional status than the target population. On the other hand, five-province in 2012 over Iran reported that only 31% of the participants were independent in IADL; which was a little less than our study. This discrepancy may be due to this fact that they evaluated less than 8 domains in study, while we used standard version of IADL questionnaire (8 domains).²²

Pain

Suffering from any chronic pain was reported in near four fifth of the participants, and we observed the highest rate among the age group 70 to 79 years old, which is almost similar to the study of Zarei et al in the South of Iran (76% in over 70 years old population).²³ The most common reported sites of chronic pain in our study were joints, which Zarei et al has also reported joint pain as the most prevalent pain site (foot and joint pain had the share of 31.9%).

As chronic pain is a common debilitating complain in older adults, which affects mental health,²⁴ physical, and social activity also imposes extra costs on health system,^24,25 it seems that the detection and management of chronic pain should be a priority of the primary health care system for older adults, and can effectively improves different dimensions of older adults’ health and decreases the refers to physicians, as well.

Self-perceived health

Most of the participants reported optimal self- perceived health (excellent, good and fair), which is comparable with the findings of Ghalichi et al (about 70% in the group of > 65 years)²⁶ and the study of Mirzaie (57.5% good, 5.1% excellent and 8.8 % very good),²⁷ despite their different method of categorization. Beside all other factors, SPH is deeply dependent to culture. It looks like that Iranian older people less intersected in reporting their health condition as ‘‘excellent’’ or ‘‘very good’’.²⁸ Therefore, most of the participants reported fair health (about 60%) instead of good or excellent. According to the results, SPH is deteriorated by older age as the poor health category changes from about 8% in 60–69 years old to about 32% among equal or over 80 years old adults. This deterioration can be due to the deterioration in physical health and functional status. In addition, about 45% of the participants reported improvement in their health status in comparison with the previous year and just about 20% of them estimated their health condition became worse. As self- perceived health is an important context-based variable, which can predict mortality rate¹⁴ in older adults, further studies maybe need to evaluate the factors that affect the perceived health status included depression and mood condition.²⁹

Urine and fecal continence

Among the participants, urinary incontinence (UI) reported in more than one fifth of the participants reported occasional UI, and less than 4% of them reported no had control. The prevalence of UI increased by age, so that in the age group ≥80 years, more than 40% were suffering from occasional or sustain UI. However, the prevalence of UI was reported more than 60% in older women in Yazd. As culturally, incontinence is assumed as a normal age-related change and older people think that there is no an effective treatment for it, they don’t seek medical treatment and try to cope with this problem, which is perceived as a matter of shame in their view.³⁰ It imposes not only a huge costs on society, but also is associated with depression and mortality.³¹

Fecal incontinence is also another embarrassing feeling, which is called as “silent suffering”.³² In agreement with the reported prevalence in the community based studies³³ near to 8% of the participants reported fecal incontinence(occasional or general), while in Iran Alimohammadian et al reported 18.4% FI in over 40 years older women.³² It seems that UI is usually unrecognized by primary health physicians, whereas there are a lot of noninvasive interventions to improve incontinence in older adults.³⁴ Applying screening programs for both urine and stool incontinence in primary care settings can be helpful in detecting and treating of incontinence and ultimately improves the quality of life among this age group.

Visual and hearing

While, the prevalence of blindness has been reported in 4% in a systematic review on visual problems of people over 50 years in Iran,³⁵ in the present research, it was reported in less than 0.5% of the participants, which could be because of less participation of blind people in this study. Although less than 30% of the participants reported a kind of hearing impairment and only less than 10% of them used hearing aid. Despite the high costs of hearing aid and lack of knowledge among older people and their family members, it seems that there is not cultural acceptance for hearing aids in Iranian older adults.

We used telephone survey with a stratified simple random sampling based on the restricts of Tehran metropolitan and all cities exist in Tehran province. This method is a known valid method for choosing a representative population for enrollment into studies.³⁶

Strengths and limitations

Recruiting sufficient participants through random sampling, which consisted population of all counties and districts of Tehran province, and the acceptable response rate (about 90%) was the strength point of this study. However, as the study was a telephone based survey, and face to face interview was not possible, most of the collected data were based on the judgment of older adults and sometimes may be biased, despite the quest’s effort. Moreover, the end stage older adults who were not able to communicate were excluded. Therefore, the functional status and health profile may be estimated a bit better than the real situation.

Conclusion

The results of the present study can provide a good view about the health profile of older adults, including pain, functional status, sphincter control, chronic diseases, sensory status, and SPH. Since the proportion of the elderly over the age of 60 is rising, the task of caring for this population will most likely be transferred from family members to government care facilities for the elderly in the near future. Given this, governments must accurately predict the aging populous necessities. One of the results of this study was the high incidence of chronic pain among the elderly, which, as it impairs their quality of life, necessitates attention to this point among these people’s relevant physicians. Future studies should prioritize SPH as an important predictor of mortality rates. Urinary or fecal incontinence should be included in screening programs for older adults. This is a telephone-based study that, despite its flaws, will assist researchers and policymakers in future planning for care for older adults in the Metropolitan province.

Acknowledgements

The authors would like to acknowledge all of the older adults who participants in this research

Authors’ contributions

MSR, NM, and FSH participated in the study design, final revision and edit. MP, SK, AND ME participated in the sequence alignment and draft the manuscript. SN, FB, and RH participated in the data acquisition. FSH and HA performed statistical analysis. BL participated in critical review. All authors read and approved the final manuscript.

Funding

This work was financially supported by Tehran University of Medical Sciences.

Ethical approval

Verbal informed consent was obtained via telephone interview. The ethical approval was taken from the Ethical Research Committee of Tehran University of Medical Sciences (TUMS) (ethical code: 26572).

Competing interests

The authors declare that they have no conflict of interest.

Supplementary Materials

Supplementary file 1 contains Tables S1-S10.

References

1. Chatterji S, Byles J, Cutler D, Seeman T, Verdes E. Health, functioning, and disability in older adults--present status and future implications. Lancet 2015; 385(9967):563-575. doi: 10.1016/s0140-6736(14)61462-8 [Crossref]
2. Rahman MS. Health care in aged population: a global public health challenge. J Med 2019; 20(2):95-97. doi: 10.3329/jom.v20i2.42010 [Crossref]
3. Fried LP, Walston JD, Ferrucci L. Frailty. In: Halter JB, Ouslander JG, Tinetti ME, Studenski S, High KP, Asthana S, eds. Hazzard’s Geriatric Medicine and Gerontology. 6th ed. McGraw-Hill; 2009.
4. Deshpande R, Asch WS, Malinis M. Frailty and perioperative outcomes. Curr Anesthesiol Rep 2018; 8(2):225-231. doi: 10.1007/s40140-018-0275-4 [Crossref]
5. Beard JR, Bloom DE. Towards a comprehensive public health response to population ageing. Lancet 2015; 385(9968):658-661. doi: 10.1016/s0140-6736(14)61461-6 [Crossref]
6. Shahraz S, Forouzanfar MH, Sepanlou SG, Dicker D, Naghavi P, Pourmalek F. Population health and burden of disease profile of Iran among 20 countries in the region: from Afghanistan to Qatar and Lebanon. Arch Iran Med 2014; 17(5):336-342.
7. Bähler C, Huber CA, Brüngger B, Reich O. Multimorbidity, health care utilization and costs in an elderly community-dwelling population: a claims data based observational study. BMC Health Serv Res 2015; 15:23. doi: 10.1186/s12913-015-0698-2 [Crossref]
8. Griffith LE, Gruneir A, Fisher K, Panjwani D, Gafni A, Patterson C. Insights on multimorbidity and associated health service use and costs from three population-based studies of older adults in Ontario with diabetes, dementia and stroke. BMC Health Serv Res 2019; 19(1):313. doi: 10.1186/s12913-019-4149-3 [Crossref]
9. Noroozian M. The elderly population in Iran: an ever growing concern in the health system. Iran J Psychiatry Behav Sci 2012; 6(2):1-6.
10. Tabrizi JS, Farahbakhsh M, Sadeghi-Bazargani H, Nikniaz L. Prevention and control of non-communicable diseases in Iranian population: life style promotion project phase II: study protocol. Iran J Public Health 2018; 47(9):1397-1405.
11. Arab-Zozani M, Alizadeh Khoei M, Janati A. Escape from the darkness: the need to provide elder-friendly care policies in Iran. Iran J Public Health 2018; 47(6):934-935.
12. Statistical Center of Iran. Findings of the 2016 National Population and Housing Census Tehran 2018. Available from: https://www.amar.org.ir/english/Population-and-Housing-Censuses/Census-2016-Detailed-Results. Accessed December 8, 2017.
13. Paúl C, Ribeiro O, Teixeira L. Active ageing: an empirical approach to the WHO model. Curr Gerontol Geriatr Res 2012; 2012:382972. doi: 10.1155/2012/382972 [Crossref]
14. Bamia C, Orfanos P, Juerges H, Schöttker B, Brenner H, Lorbeer R. Self-rated health and all-cause and cause-specific mortality of older adults: individual data meta-analysis of prospective cohort studies in the CHANCES consortium. Maturitas 2017; 103:37-44. doi: 10.1016/j.maturitas.2017.06.023 [Crossref]
15. Szybalska A, Broczek K, Puzianowska-Kuznicka M, Slusarczyk P, Chudek J, Skalska A. Self-rated health and its association with all-cause mortality of older adults in Poland: the PolSenior project. Arch Gerontol Geriatr 2018; 79:13-20. doi: 10.1016/j.archger.2018.07.016 [Crossref]
16. Gyasi RM, Phillips DR. Gender, self-rated health and functional decline among community-dwelling older adults. Arch Gerontol Geriatr 2018; 77:174-183. doi: 10.1016/j.archger.2018.05.010 [Crossref]
17. Gijzel SMW, van de Leemput IA, Scheffer M, Roppolo M, Olde Rikkert MGM, Melis RJF. Dynamical resilience indicators in time series of self-rated health correspond to frailty levels in older adults. J Gerontol A Biol Sci Med Sci 2017; 72(7):991-996. doi: 10.1093/gerona/glx065 [Crossref]
18. Gyasi R, Buor D, Adu-Gyamfi S, Adjei PO, Amoah PA. Sociocultural hegemony, gendered identity, and use of traditional and complementary medicine in Ghana. Women Health 2018; 58(5):598-615. doi: 10.1080/03630242.2017.1321608 [Crossref]
19. Ghasemi S, Keshavarz Mohammadi N, Mohammadi Shahboulaghi F, Ramezankhani A, Mehrabi Y. Physical health status and frailty index in community dwelling older adults in Tehran. Iran J Ageing 2019; 13(5):652-665. doi: 10.32598/SIJA.13.Special-Issue.652 [Crossref]
20. Sharifi F, Alizadeh-Khoei M, Saghebi H, Angooti-Oshnari L, Fadaee S, Hormozi S. Validation study of ADL-Katz scale in the Iranian elderly nursing homes. Ageing Int 2018; 43(4):508-523. doi: 10.1007/s12126-017-9314-6 [Crossref]
21. Alizadeh Khoei M, Akbari ME, Sharifi F, Fakhrzadeh H, Larijani B. Translation and validation of the activities of daily living scale with Iranian elderly cancer patients treated in an oncology unit. Asian Pac J Cancer Prev 2013; 14(5):2731-2737. doi: 10.7314/apjcp.2013.14.5.2731 [Crossref]
22. Taheri Tanjani P, Motlagh ME, Moradi Nazar M, Najafi F. The health status of the elderly population of Iran in 2012. Arch Gerontol Geriatr 2015; 60(2):281-287. doi: 10.1016/j.archger.2015.01.004 [Crossref]
23. Zarei S, Bigizadeh S, Pourahmadi M, Ghobadifar MA. Chronic pain and its determinants: a population-based study in Southern Iran. Korean J Pain 2012; 25(4):245-253. doi: 10.3344/kjp.2012.25.4.245 [Crossref]
24. Rashedi V, Asadi-Lari M, Foroughan M, Delbari A, Fadayevatan R. Mental health and pain in older adults: findings from Urban HEART-2. Community Ment Health J 2017; 53(6):719-724. doi: 10.1007/s10597-017-0082-2 [Crossref]
25. Dueñas M, Ojeda B, Salazar A, Mico JA, Failde I. A review of chronic pain impact on patients, their social environment and the health care system. J Pain Res 2016; 9:457-467. doi: 10.2147/jpr.s105892 [Crossref]
26. Ghalichi L, Nedjat S, Majdzadeh R, Hoseini M, Pournik O, Mohammad K. Determinants of self-rated health in Tehran, from individual characteristics towards community-level attributes. Arch Iran Med 2015; 18(5):266-271.
27. Mirzaie M. Factors affecting the elderly self-perceived health status. Iran J Ageing 2008; 3(2):539-546.
28. Kandula NR, Lauderdale DS, Baker DW. Differences in self-reported health among Asians, Latinos, and non-Hispanic whites: the role of language and nativity. Ann Epidemiol 2007; 17(3):191-198. doi: 10.1016/j.annepidem.2006.10.005 [Crossref]
29. Morowatisharifabad MA, Rezaei Pandari H, Mazyaki A, Bandak Z. Prevalence of urinary incontinence among elderly women in Yazd, Iran: a population-based study. Elder Health J 2015; 1(1):27-31.
30. Shaw C, Wagg A. Urinary incontinence in older adults. Medicine 2017; 45(1):23-27. doi: 10.1016/j.mpmed.2016.10.001 [Crossref]
31. John G, Bardini C, Combescure C, Dällenbach P. Urinary incontinence as a predictor of death: a systematic review and meta-analysis. PLoS One 2016; 11(7):e0158992. doi: 10.1371/journal.pone.0158992 [Crossref]
32. Alimohammadian M, Ahmadi B, Janani L, Mahjubi B. Suffering in silence: a community-based study of fecal incontinence in women. Int J Colorectal Dis 2014; 29(3):401-406. doi: 10.1007/s00384-013-1809-3 [Crossref]
33. Ng KS, Sivakumaran Y, Nassar N, Gladman MA. Fecal incontinence: community prevalence and associated factors--a systematic review. Dis Colon Rectum 2015; 58(12):1194-1209. doi: 10.1097/dcr.0000000000000514 [Crossref]
34. Goepel M, Kirschner-Hermanns R, Welz-Barth A, Steinwachs KC, Rübben H. Urinary incontinence in the elderly: part 3 of a series of articles on incontinence. Dtsch Arztebl Int 2010; 107(30):531-536. doi: 10.3238/arztebl.2010.0531 [Crossref]
35. Mohammadi SF, Saeedi-Anari G, Ashrafi E, Mohammadi SM, Farzadfar F, Lashay A. Prevalence and major causes of visual impairment in Iranian adults: a systematic review. Middle East Afr J Ophthalmol 2017; 24(3):148-155. doi: 10.4103/meajo.MEAJO_168_16 [Crossref]
36. Glass DC, Kelsall HL, Slegers C, Forbes AB, Loff B, Zion D. A telephone survey of factors affecting willingness to participate in health research surveys. BMC Public Health 2015; 15:1017. doi: 10.1186/s12889-015-2350-9 [Crossref]