Risk factors for unintentional injuries among the rural elderly: a county-based cross-sectional survey

1SCienTifiC REPORTS | 7: 12533 | DOI:10.1038/s41598-017-12991-3
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Risk factors for unintentional
injuries among the rural elderly:
a county-based cross-sectional
survey
Hongping Zhang1, Feng Wei2, Mo Han2, Jianquan Chen3, Songxu Peng1 & Yukai Du1
This study aimed to provide evidence for the prevention and reduction of unintentional injuries in the
rural elderly by analysing epidemiological data of injuries among rural older adults (65+) and identifying
the involved risk and protective factors. This study analysed all information, including the social
demographic characteristics, chronic disease condition, lifestyle, living environment, mental health,
activities of daily living and detailed information about the nature of the injuries. Chi-square tests, rank
tests and a multivariate logistic regression were performed. The prevalence of unintentional injuries
was 44.4%; according to the multivariate regression analysis, ten variables, including gender, floor tiles,
cane use, sleeping duration, roughage intake frequency, mental health status, diabetes, arthritis and
cataracts, were involved in the injury patterns. Low roughage intake (OR = 2.34, 95% CI 1.64–3.35),
the use of a cane (OR = 1.78, 95% CI 1.31–2.41), a sleeping duration of five hours (OR = 1.75, 95% CI
1.27–2.42) and severe mental disorders (OR = 1.61, 95% CI 1.01–2.57) were the top 4 risk factors. In
conclusion, we found that unintentional injuries among the rural elderly were closely related to chronic
disease, mental health and residence environment. These findings could be beneficial for the prevention
of unintentional injuries and for policy makers and health service managers.
Unintentional injuries among older adults are an increasing public health concern due to the overall ageing of
the population. The mortality rate due to injury has increased over the past decade among adults aged 65 years or
older 1–4 . According to Karb, the mortality rate (per 100,000) due to all unintentional injuries among adults aged
65–84 years was 66.87, which is approximately 10 times that observed among children aged 0–14 years; moreover,
the mortality rate among those aged 85 years or older was 337.27, which is nearly 50 times that observed among
children aged 0–14 years in the United States between 1999 and 2012 5 . In Korea, injury-related mortality has
increased among adults aged 65 years or older. In particular, injury-related mortality among women older than
80 years has doubled since 1996. Falls replaced transport as the leading cause of injury-related deaths among
the elderly 6 . In addition, the elderly are often afflicted with a variety of diseases, such as cardiovascular disease
and diabetes, that reduce the likelihood of survival in the case of non-fatal injuries. Furthermore, the increasing
rates of emergency department (ED)-treated and the high number and proportion of inpatient trauma days due
to unintentional injuries among elderly adults poses a challenge to the health care system and increases the eco-
nomic burden on society 3,7,8
. Therefore, more effective measures are needed to prevent and reduce unintentional
injuries among elderly people and minimize the negative health effects and increasing health costs.
Age has been considered a risk factor for unintentional injuries among the elderly because the risk of unin-
tentional injury is higher among the older-elderly population6,9–11 . However, age has also been reported to have
no influence on the rate of injuries among the elderly 3,12 . According to Saveman, the injury rate among elderly
females is higher than that among elderly males 10 ; the unintentional fatal injury rate is higher among females
than that among males; and females older than 70 years are more likely to fall than males, leading to a greater
1Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong
University of Science & Technology, HangKong Road 13, Wuhan, 430030, China. 2Centers for Disease Prevention &
Control of Huangpi District of Wuhan, BaiXiu Street 255#, Huangpi District, Wuhan, 430300, China. 3Department
of Disease Control, Health and Family Planning Commission of Huangpi District of Wuhan, BaiJing Street 224#,
Huangpi District, Wuhan, 430300, China. Correspondence and requests for materials should be addressed to Y.D.
(email: [e-mail])
Received: 17 February 2017
Accepted: 14 September 2017
Published: xx xx xxxx
OPEN

www.nature.com/scientificreports/2SCienTifiC REPORTS | 7: 12533 | DOI:10.1038/s41598-017-12991-3
likelihood of bone fractures 2 . Certain chronic diseases, including lumbar spondylosis, orthostatic hypotension,
diabetes and cataracts, are risk factors for falls among elderly individuals 13
. Severe bilateral visual deficits increase
the risk of unintentional mortality among adults over the age of 18 years (including the elderly)14
. Depression15–17
and other mental illnesses 18 are related to the risk of injuries. Elderly individuals with Alzheimer’s disease are
more prone to unintentional poisoning19
. The use of medications also explains the increased rate of unintentional
injuries among the elderly; for example, elderly individuals who consume opioid drugs are more likely to fall20 .
Furthermore, sleep duration affects unintentional injuries among adults; sleeping less than 6 hours was a risk
factor for unintentional injuries21
. The fall risk among elderly individuals is closely related to the activities of daily
living (ADL) capability, physical activity habits, poor living conditions and environmental factors22
. Furthermore,
poverty at the county level confers a greater risk of unintentional injury, and high poverty areas have shouldered
the burden of the recent national increases in the mortality rate due to unintentional injuries2,5,23
. In India, more
than 80% of unintentional injury-related deaths occurred in rural areas2 . There is an increasing socioeconomic
disparity among all combined unintentional injuries. The injuries observed in rural areas and among individual
from low socioeconomic classes are more severe 24
.
In China, most elderly people continue to live in the countryside. Because the young adult labour forces have
migrated from the rural areas to the cities, the elderly population remaining in the rural areas must live alone
without the support of their adult offspring (usually referred to as “empty nesters”). More attention should be paid
to the older rural population because this population is more likely to experience unintentional injuries. Most
elderly people work as active farmers under poor economic conditions with less support from younger adults.
Population-based surveys covering the range of injuries among older rural adults are scarce 10
. Our study attempts
to address these shortcomings.
In this study, we performed cluster sampling using our self-designed questionnaire. The questionnaire assesses
social demographic characteristics, financial situations, conditions of offspring, prevalence of chronic disease,
living environment, mental condition, ADL and instrumental ADL (IADL) among elderly individuals. This study
aims to identify policies, programmes, and resources that ensure a safe environment and promote safe behaviours
to prevent injury. Therefore, the situations responsible for unintentional injuries and the risk and protective fac-
tors that minimize these injuries were analysed. Comparisons of specific injury-related mortality between states
should be conducted with caution because the large differences in the unspecified injury mortality rates across
states could create a bias4
. Furthermore, unintentional injuries are not homogeneous phenomena from an epide-
miological transition perspective25 . This study was conducted amongst the rural population in one entire county
under the jurisdiction of Wuhan City, Hubei Province, China.
Results
General description of the investigation. Of the 3,900 questionnaires distributed, we received 3,752
completed questionnaires, representing a response rate of 96.2%. The database included 1,673 males (44.6%) and
2,079 females (55.4%), and the average age of these individuals was 72.74 ± 6.44 years, with a range of 65 to 100
years. Of those surveyed, 64.8% were 65–74 years old, and 5.3% were 85 years old or older. In total, 1,665 injuries
were reported by 805 victims in a sample of 3,752 respondents aged 65 years and older during the 12-month
period covered by this investigation. The observed injury prevalence in this rural elderly population was 44.4%
(Table 1). The questionnaire responses included 487 cases (59.8%) of one injury, 127 cases (15.8%) of two injuries
Causes of injuries
Total Sex Age group in years (y)
N = 3752
n (%)
Male
N = 1673
n (%)
Female
N = 2079
n (%) P-value
65–74
N = 2431
n (%)
75–84
N = 1122
n (%)
≥85 N = 199
n (%) P-value
Total 1665(44.4) 578(34.5) 1087(52.3) 0.000** 1035(42.6) 548(48.8) 82(41.2) 0.130
Falls 1124(30.0) 347(20.7) 777(37.4) 0.000** 639(26.3) 430(38.3) 55(27.6) 0.000**
Cuts 201(5.4) 79(4.7) 122(5.9) 0.476 149(6.1) 49(4.4) 3(1.5) 0.021*
Choking or
swallowing a foreign
body
164(4.4) 77(4.6) 87(4.2) 0.415 121(5.0) 33(2.9) 10(5.0) 0.195
Burns 36(1.0) 5(0.3) 31(1.5) 0.013* 23(0.9) 7(0.6) 6(3.0) 0.258
Traffic accidents 31(0.8) 20(1.2) 11(0.5) 0.004* 23(0.9) 7(0.6) 1(0.5) 0.485
Sunstroke 30(0.8) 12(0.7) 18(0.9) 0.435 23(0.8) 6(0.5) 1(0.5) 0.729
Crushing accidents 22(0.6) 13(0.8) 9(0.4) 0.044* 16(0.7) 6(0.5) 0(0.0) 0.630
Animal bites 19(0.5) 10(0.6) 9(0.4) 0.219 11(0.4) 7(0.6) 1(0.5) 0.706
Percussions 17(0.5) 3(0.2) 14(0.7) 0.326 11(0.4) 1(0.1) 5(2.5) 0.180
Poisoning 6(0.2) 5(0.3) 1(0.0) 0.055 6(0.2) 0(0.0) 0(0.0) 0.284
Drowning 4(0.1) 2(0.1) 2(0.1) 0.638 4(0.2) 0(0.0) 0(0.0) 0.367
Domestic violence 3(0.1) 0(0.0) 3(0.1) 0.262 1(0.0) 2(0.2) 0(0.0) 0.812
Electric shock 1(0.0) 1(0.1) 0(0.0) 0.206 1(0.0) 0(0.0) 0(0.0) 0.779
Other injuries 7(0.2) 4(0.2) 3(0.1) 0.504 7(0.3) 0(0.0) 0(0.0)
Table 1. Prevalence of different types of unintentional injuries by age and gender among the study population.
*P < 0.05; **P < 0.01; % = prevalence.

www.nature.com/scientificreports/3SCienTifiC REPORTS | 7: 12533 | DOI:10.1038/s41598-017-12991-3
and 191 cases (23.7%) of three or more injuries. Falls (30.0%) and cuts (5.4%) were the most common uninten-
tional injuries, followed by choking or swallowing a foreign body (4.4%), burns (1.0%), traffic accidents (0.8%),
and sunstroke (0.8%) (Table 1).
Sex- and age-based injury patterns. The incidence of the unintentional injuries was significantly higher
among the female respondents (52.3%) than among the male respondents (34.5%) (P < 0.001). Females were
significantly more likely to experience fall-related injuries (37.4% vs. 20.7%, P < 0.001) and burn injuries (1.5%
vs. 0.3%, P = 0.049). Males were significantly more likely to experience a traffic injury (1.2% vs. 0.5%, P = 0.004)
and crushing injuries (0.8% vs. 0.4%, P = 0.044) than females (Table 1).
The prevalence of the injuries varied according to the age group and type of injury (Table 1). The group of
participants aged 75–84 years had the highest rates of all injuries (48.8%), followed by those aged 65–74 years
(42.6%), and the group of participants aged 85 years or older had the lowest rate (41.2%). However, no signif-
icant differences were observed among these groups (P = 0.130). The group aged 75–84 years had higher rates
of fall-related injuries (38.3%) than the older group (27.6%) or younger group (26.3%) (P < 0.001). The group
aged 65–74 years had higher rates of cut injuries (6.1%) than the older group (4.4%) and the oldest group (1.5%)
(P = 0.010).
Treatments and costs. Upper and lower limb injuries were the most commonly reported injuries, followed
by head and neck injuries and spine-backbone/back injuries. Bruises, fractures and sprains were the top 3 most
common injuries. The most common settings in which the injuries occurred were at home (40.6%) and the work-
place (22.3%) (Table 2). In total, 44.4% (n = 357) of the study population sought medical help, 28.2% (n = 227) of
the study population did not receive any treatment and 27.4% (n = 221) of the study population self-medicated.
The total medical costs of the 1,665 injuries were 1,656,845 RMB; 144 people (20.3%) were admitted for 2,346
days in hospitals, representing an expenditure of 1,330,600 RMB. In total, 51.3% of the elderly was covered by
the New Rural Cooperative Medical Care Scheme, 40.3% of the elderly paid for their treatments and 8.4% of the
elderly used another health insurance carrier, such as free medical service or commercial insurance (Table 3).
Risk factors. Our study identified 27 factors related to injuries by performing a single-factor logistic regres-
sion analysis with the occurrence of injuries as the dependent variable. This study subsequently assessed the
above-mentioned 27 factors by performing a multivariable logistic regression analysis. According to this analysis,
ten variables, including gender, the presence or absence of floor tiles, a residence near a road, use of a cane or
walking stick, sleep duration, food intake, mental health, diabetes, arthritis and cataracts, were all factors in the
injury patterns (presented in Table 4).
In general, women had a 46% greater chance of injury than men, and these higher odds reached 72% for
fall-related injuries. Compared with people with a non-slippery floor, elderly adults with slippery floors had a 10%
higher probability of injury, and those who had no floor (i.e., those living in a dwelling with an earth or cement
floor) had a 60% higher chance of sustaining an injury. Using approximately 9 hours of sleep as a reference, the
adjusted injury risk (odds ratio) for those who sleep less than 4 hours/day was 0.88. The odds ratio was 1.75 for
those sleeping 5 hours per day, 1.45 for those sleeping 6 hours per day, 1.01 for those sleeping 8 hours per day and
1.10 for those sleeping 9 hours or more per day. The risk difference was significantly different between the 5- and
6-hour cohorts. In this study, the risk increased as sleep duration decreased from 7 hours to less than 4 hours.
The use of a cane or walking stick increased the odds of injury by 78%. The group with the lowest food intake
had a 2.34-fold higher probability of sustaining an injury than the group with normal food intake. Individuals
with severe mental disorders were 61% more likely to sustain recurrent injuries and 59% more likely to sustain an
injury than the individuals in the moderate mental disorder group. People who had a chronic disease had a higher
risk of injury as follows: individuals with diabetes had a 42% higher probability of sustaining an injury, individu-
als with arthritis had a 27% higher probability, and individuals with cataracts had a 38% higher probability.
Discussion
This is the first study to investigate the rate of unintentional injury among rural elderly individuals using compre-
hensive information regarding the socio-demographic characteristics, chronic disease condition, lifestyle, living
environment, mental condition, ADL and IADL. The prevalence of unintentional injuries was 21.5% in this rural
elderly population. The top six unintentional injuries were falls, cuts, choking or swallowing a foreign body,
burns, traffic accidents and sunstroke. Prior domestic and foreign studies mostly investigated the elderly in a city
or community environment, in which falling and traffic injuries are the most common injury types 2,26 . By con-
trast, this study was conducted among the elderly in rural areas, and injuries from cuts ranked the highest because
this population typically uses blades or other sharp-edged implements for agricultural production. Some elderly
individuals use wood instead of gas or coal as fuel to heat their homes and cook. Therefore, these individuals are
prone to injuries from blades as they prepare wood for burning. Because these individuals use wood for heat and
cooking, they are also more prone to burns sustained when feeding the stove. Due to their age, their potential to
experience a burn- or fire-related injury increases as a function of the ageing process, co-morbidities, and limited
financial means 27 . These individuals are also prone to sunstroke while working outside. In this investigation, the
incidence of swallowing a foreign body and choking was 1.6%, ranking as the third most common injury, which
has not been observed in other studies. The elderly are more prone to dysphasia-choking than children, who are
more prone to choke by swallowing a foreign body. Among unintentional deaths in Japan, choking ranks as the
number one cause28 . Among the approximately 800 choking cases attributed to food, mochi ranks the highest at
20%, and this rate is particularly high among elderly individuals aged more than 65 years. Mochi is a traditional
Japanese food and an important festive feature during the New Year’s holiday, particularly among the elderly.
Mochi is made by steaming sticky rice. Mochi is highly cohesive and adhesive and can easily lead to choking. The