Workplace injury and associated factors among construction workers in Gondar town, Northwest Ethiopia

Background The construction industry is one of the most hazardous working areas, where the highest number of labourers engaged. However, the predisposing factors for occupational injury in the construction sites in Ethiopia are not well investigated. This study was, therefore, conducted to assess the magnitude of occupational injury and associated factors among construction workers in Gondar town, northwest Ethiopia. Methods This cross-sectional study was conducted on 566 construction workers. Systematic random sampling technique was used to select study subjects. Data were collected using structured questionnaire and observation checklist. Multivariable binary logistic regression analysis was used to identify variables significantly associated with occupational injury on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p < 0.05. Results The overall prevalence of work-related injury in 3 months prior to the survey was found to be 39% (95% CI = 35.0–43.1%). The occurrence of occupational injury was associated with single workers [AOR = 0.50, 95% CI = 0.25, 0.97], longer service year [AOR = 2.79, 95% CI = 1.72–4.53], poor attention to work [AOR = 2.65, 95% CI = 1.33, 5.29], working with vibrating hand tools [AOR = 3.23, 95% CI = 1.19, 8.76], no aware about occupational hazards [AOR = 4.66, 95% CI = 1.99, 10.87], and alcohol consumption [AOR = 3.16, 95% CI = 2.09, 4.79]. Conclusion High prevalence of occupational injury was reported in the study area. Cut and fall were the leading causes. Marital status, service year, attention to work, use of vibrating hand tools, awareness about occupational hazards, and drinking alcohol were identified as factors associated with occupational injury. Therefore, health and safety trainings have to be taken place to aware workers about occupational injury and safety issues. Regular workplace supervision and provision of appropriate personal protective equipment (PPE) are also needed to prevent occupational injury. The findings of this study are useful to design and implement injury prevention strategies in the country. The study also contributes to the current literature as health and safety information is limited, especially in developing countries.


Background
The construction industry has been considered an accident-prone industry. That is because construction sites are often filled with potential hazards that can lead to serious injury or death [1,2]. Construction workers face a risk of fatal and non-fatal injury higher than any other groups of workers [3]. Although countries differ substantially in their structural industrial distribution or level of occupational health and safety, injuries in the construction industries are the major health and safety concerns in many countries [4]. Moreover, the rate of death of workers is higher in the construction industry than in any other industry [1].
Within the construction industry, the risk of fatality is 5 times higher than in manufacturing, whilst the risk of a major injury is 2.5 times higher [5]. The problem of death and injury as a result of the workplace accident has now been recognized as a global phenomenon. The construction industry accounts for 55,000 fatal injuries each year [1]. Besides, construction injury causes huge economic losses. Globally, the direct and indirect costs of fatal and nonfatal construction injury have been estimated over 10 billion USD per year [6].
Accident causalities in the construction industry is complex and multifaceted and accident prevention begins with having a clear understanding of those factors [7]. Personal and work characteristics combined with the working environment and organizational factors are believed toinfluence the creation of a hazardous environment that could be triggered by differentmechanisms that cause an accident [8][9][10]. Most of the accidents in the construction industry occurred because of insufficient safety measures [11]. Human errors are mainly responsible forconstruction accidents [12][13][14]. Site conditions or work environments play an important role in construction accidents [10]. Moreover, the temporary and transitory nature of construction sites are claimed to contribute to accidents [15]. While environmental factors such as climate, temperature, and geographical conditions could be considered as typical characteristics for construction sites [16]. Organizational factors may include characteristics referring to construction organisations and project-based procurement of works [17]. Size of company [18][19][20], age [21][22][23][24], gender [18][19][20]25], education [19] and type of work [26][27][28] are also associated with occupational injury.
In the developed countries, several attempts have been made to investigate factors influencing safety performance on construction sites. However, the predisposing factors for occupational injury in the construction sites in Ethiopia are not well investigated. This study was, therefore, conducted to assess the magnitude of occupational injury and associated factors among construction workers in Gondar town, northwest Ethiopia.

Design and settings of the study
An institutional-based cross-sectional study design was conducted among construction workers in Gondar town. More than 20 construction sites were found in Gondar town as of April 2015 and the major sites are owned by eight different companies. Around 2586 workers were engaged in different working units in all sites. Workers who directly engaged in different working units were considered as study subjects and workers who were not engaged in construction works like administrative workers were excluded from the study.

Sample size determination
The sample size was determined using single population proportion formula with the following assumptions: prevalence of occupational injury (p) = 38.7% [29], margin of error (w) = 4, 95% confidence interval (standard normal probability), and level of significance (α) = 4. Therefore, the sample size (n) was computed as n

Sampling technique and sampling procedure
More than 20 construction sites with more than 2586 workers are found in Gondar town as of April 2015. Eight construction sites were selected using simple random sampling technique. All workers who actively engaged in different sections were included and persons who had no exposure to occupational hazards like office workers were excluded from the study. Hence, the number of workers at each site varied; the sample size was proportionally allocated (Table 1). Finally, the study subjects from each site were selected by simple random sampling technique (using random number generator) using workers in the registration book as a sampling frame.

Description of study variables Dependet variable
Occupational injury, the primary outcome variable of this study, is defined as any physical damage of the human body or tissue like laceration, cut, puncture, fracture, dislocation, amputation, electrocution, ear injury, and eye injury results from harmful contact between people and objects, substances, or other things in their surroundings.

Independet variables
Utilization of PPEs Is defined as use of suitable protective equipment like hand glove, toetector/feet wear, respirator, face mask, reinforced cloth, goggle and helmet on duty. Manual handling Is defined as any load by physical effort incorporates lifting, pushing, pulling, putting down, caring and moving from the ground level and higher level.
Health and safety training Is any formal or informal health and safety education provided for workers to create basic understanding of occupational health, workplace hazards, injury prevention and safety.
Attention to work Is a physical and mental due attention or focus given for the work only.
Alcohol use Male and female participants who drink more than six and five glasses or bottles or cans of any alcoholic beverage, such as beer, wine and Tela (local beverage) respectively on a regular work or weekend days, including the off-work hours were considered as drunker.
Hazard awareness Is defined as an existed knowledge or understanding of occupational hazards. Moreover, health and safety supervision, working hours per week, working section, and socio-demographic characteristics were other predictor variables considered in this study.

Data collection tools and data collection procedures
Data were collected using a structured questionnaire and observational checklists. The data collection tools were adopted from other similar published studies [29][30][31] with simple modification to address contextual issues related to study setting and participants. The questionnaire consisted of socio-demographic information, work-related injury characteristics, work environment and ergonomic related information, and workers behavior-related information. The tools were pretested on workers who were not actually part of the study having similar characteristics with the study subjects in different town and necessary correction was done. Training was given for data collectors and supervisors on data collection procedures and data collection tools. The overall physical condition of the workers and the working condition were observed using checklists [32][33][34][35]. Working conditions and safety practices were the items included in the checklists. We immediately checked and corrected completeness of data before the collectors move to the next interview. Supervisors checked the completeness of all the filled questionnaires daily and 5% of the collected questionnaires were repeated. Furthermore, double data entry and software assisted data cleaning were employed.

Data processing and analysis
Data were entered using EPI-INFO version 3.5.3 and exported to statistical package for social sciences (SPSS) version 20.0 for further analysis. Univariable binary logistic regression analysis was used to choose variables for the multivariable binary logistic regression analysis on the basis of p-value less than 0.2. In the multivariable binary logistic regression analysis, statistically significant variables were identified on the basis of AOR with 95% CI and p < 0.05. Model goodness-of-fit was checked by Hosmer-Lemeshow test. Multicollinearity was also checked.

Socio-demographic characteristics
In this study, 566 construction workers participated. This gives 95% response rate. Of these, 295 (52.1%) were male. The mean age of the participants was 25.78 years with ±6.58 standard deviation. Three hundred fifty (61.8%) of the workers attended primary education. Three hundred ninetynine (70.5%) of the study subjects had five and below years of work experience in the construction industry. About twothird, 358 (63.3%) of the construction workers were daily labourers ( Table 2).

Working condition and workers behaviour
Fifty-four (9.5%) of the respondents worked for more than 48 h per week. Four hundred fifty-seven (80.7%) of the respondents had not been regularly supervised at work and 483 (85.3%) of the study subjects had not ever taken safety and health training. Four hundred sixtythree (81.8%) of the study subjects responded that their job involved manual handling and 530 (93.6%) of the workers worked with vibrating hand tools (Table 3). Four hundred fifty (79.5%) of the respondents were not using PPEs while working. The most frequently reported reason for not using PPEs was shortage of devices, which accounts for 98.2%. The remaining 116 (20.5%) of workers used PPEs. Helmet (33.6%), glove (27.6%), overall (18.1%), boots/shoes (8.6%), earplug (6.9%), respirator (2.6%), and goggle (2.6%) were commonly reported PPEs. The result of this study also showed that 17 (3%), 318 (56.2%) and 16 (2.8%) of the study subjects were smoker, drunker, and chat chewer respectively.

Magnitude of occupational injury
Out of 566 construction workers who directly engaged at different working units, 221 were injured in the last 3 months. Therefore, the overall prevalence of work-related injury was found to be 39% (95% CI = 35.0-43.1%). Of the injured workers, 56 (25.34%) experienced work-related injury more than once (Table 4). Abrasion or laceration was the leading type of injury, which accounts for 108 (48.75%). The commonest causes of injury were found to be cut by sharp objects, 62 (28.05%) and fall to ground level, 52 (23.54%) ( Table 5). The two most reported reasons for injury were the nature of the work (52.03%) and not using PPEs (16.74%) (Fig. 1). Eighty-four (38%) of injury cases were managed in the construction sites using first aid services whereas, 111 (50.2%) and 25 (13.3%) of the injured workers respectively reported as they visited health institution and as they used traditional medicine to manage the injury.

Factors associated with occupational injury
Sex, marital status, service year, safety training, attention to work, work with vibrating hand tools, hazard awareness, and alcohol consumption were selected for the multivariable analysis. As clearly indicated in Table 6, marital status, service year, attention to work, work with vibrating hand tools, awareness about occupational hazards and alcohol consumption were statistically associated with the occurrence of occupational injury in the final model. The occurrence of occupational injury among single construction workers was 50% to be lower compared with married workers [AOR = 0.50, 95% CI = 0.25, 0.97]. The likelihood of injury occurrence among workers who worked for more than 5 years was 2.79 times to be higher compared with workers who worked for five and below years [AOR = 2.79, 95% CI = 1.72, 4.53]. Those construction workers who had no attention to

Discussion
The overall three-month prevalence of occupational injury among construction workers in Gondar town was 39% (95% CI = 35.0-43.1%). The prevalence reported in this study is the same with findings of studies in Gondar city, 38.7% [30]; Maraki campus, University of Gondar, 38.7% [29]; Southeastern Ethiopia, 41.4% [36]; southwestern Ethiopia, 39.2% [37]; Addis Ababa, 38.3% [35]; and Nigeria, 39.25% [38]. The result of this study is lower than the results of other studies in Addis Ababa, 84.7% [31] and 67.7% [39], Iran, 79.8% [40]; Tamil Nadu, 44.3% [41]; and Egypt, 46.2% [42]. The result of this study is also higher than the report of other studies in Gondar, 15% [43]; Uganda, 32.4% [44]; and China 34.82% [45]. This difference might be due to differences in study settings, working conditions, level of accident prevention strategies, and socio-cultural and regulatory factors. In this study, the prevalence of occupational injury is high may be due to no regular workplace supervision, poor PPEs utilization, use of manually handled vibrating construction materials, and long working hours per week. In this study, a significant proportion of young workers engaged in the construction industry. Young workers are at higher risk of occupational injury than older age groups. Young workers face higher occupational injury risks related to their higher vulnerability. Some known contributors to youth workplace injury include potential lack of specific job training. Many youth are not aware of their legal rights and are thus illequipped to identify potential hazards and request training to appropriately manage these hazards. Youth may also feel intimidated in the workplace. They may feel powerless to change their working conditions, or too shy  to voice their concerns if they are new in their working environment [46][47][48][49].
In this study, the occurrence of occupational injury among single construction worker was 50% lower compared with married workers. The finding of this study is supported by another similar study [50]. This may be due to married workers may engage in other works without taking adequate rest. Stress and fatigue can be higher among married workers than single ones because of higher responsibilities in life. It may be led to more unsafe acts resulting in accident [50][51][52].
This study depicted that workers who reported longer working years had greater chance to occupational injury. This might be explained that accidents usually occur to workers who could still have had a long working career. Those engaged in routine activities for a long period with poor working environment may sustain job dissatisfaction; the work is insecure so that workers stayed for a long period in this insecure job had an increased vulnerability of different injury [35,[53][54][55].
The current study identified that due attention to work was associated with the occurrence of occupational injury. The odds of injury among construction workers who had no attention to work was higher than workers who had. This might be due to the fact that those workers who had no attention to work did not comply with standard work procedures, safety precautions including proper use of PPEs. In addition, workers who had no attention to work would also create hazards to their co-workers. There is some evidence to suggest that there is a link between accidents and distractibility, poor attention and mental error [56][57][58].
This study revealed that workers who used vibrating hand tools were more likely to be injured compared with their counterparts. This may be due to the type of hand tools in which construction workers used to operate their work is associated with their physical health. Physical work demands like vibration and heavy lifting aggravating the occurrence of injury. Vibrating tools can cause loss of muscle strength and reduced grip force due to incomplete muscle contraction [59].
This study found that occupational injury was significantly associated with awareness about occupational hazards. The odds of occupational injury among construction workers who had no awareness about occupational hazards was more likely to be higher. The association of awareness and injury can be justified that workers who were not aware about workplace hazards, prevention of injury and other safety measures may do work with wrong procedures and may not also comply with workplace safety strategies [39,[60][61][62].
This study indicated that the occurrence of occupational injury was associated with alcohol consumption. Construction workers who took alcohol were more likely to be injured compared with their counterparts. This finding is consistent with the findings of other studies [55,63,64]. This may be due to the fact that alcohol can impair judgmental and psychomotor skills. Alcohol took before work begins can cause effects such as fatigue and hangovers. Alcoholic workers may be more likely to be engaged in other behaviors that increase the risk of injury [65][66][67].

Limitation of the study
Workers who were absent from work due to illness were not included in this study. Therefore, the results of the study might be affected by healthy workers effect. Authors tried to check whether the absenteeism was due to occupational injury or not to minimize healthy workers effect.

Conclusion
High prevalence of occupational injury was reported in the study area. Cut and fall were the leading causes of injury. Marital status, service year, attention to work, use of vibrating tools, awareness about occupational hazards, and drinking alcohol were identified as factors associated with occupational injury. Therefore, health and safety trainings have to be taken place to aware workers about occupational injury and safety issues. Regular workplace supervision and provision of PPEs are also needed to prevent occupational injury. The findings of this study are useful to design and implement injury prevention strategies in the country. The study also contributes to the current literature as health and safety information is limited, especially in developing countries.