Occupational accidents among rice farmers in Northern Vietnam

According to the International Labour Organization (ILO), farmers face more injuries than other occupations worldwide¹. The agricultural sector is also noteworthy for its diversity of tasks, including heavy machinery operation, plant protection products², and the widespread utilization of various chemical substances³. This job requires a high level of physical effort and strength and is often performed in harsh environmental conditions and with low levels of education⁴. These factors contribute to numerous occupational hazards farmers face and usually lead to workplace accidents.

Occupational injuries in agriculture are a significant global concern. For instance, in India, a survey involving 92,793 farmers estimated the occupational injury risk, revealing that among the 21 reported agricultural incidents, 14% resulted in fatalities. The incidence rate of agricultural accidents was 0.23 per 1,000 farmers per year, and for agricultural machinery, it was 0.2 per 1,000 per year. These incidents lead to severe economic losses and significant harm to laborers due to work stoppages⁵. Similarly, in Spain, the agricultural sector ranks third in terms of workplace accidents, accounting for 4.62% of the total number of accidents during 2013–2018⁶. These global statistics highlight the inherent dangers faced by agricultural workers worldwide. In Vietnam, rice cultivation is the primary occupation for many farmers and presents its own set of occupational hazards. Although comprehensive national data on agricultural accidents in Vietnam are limited, regional studies suggest that rice farmers may experience similar or even higher rates of occupational injuries compared to their counterparts in India and Spain. For example, a study in Central Vietnam reported that 50.9% of rice farmers experienced at least one occupational accident, indicating a significant risk level⁷.

Rice farmers in Vietnam are exposed to four types of health hazards: physical, biological, chemical, and ergonomic. The production activities of rice cultivation necessitate extensive use of the musculoskeletal system and require maintaining inconvenient postures daily. Tasks such as soil preparation, planting, weeding, and harvesting involve repetitive motions and prolonged periods of bending or squatting, which increase the risk of musculoskeletal injuries^8,9. For example, a study in Bangladesh found that, the duration of threshing is significantly associated with pain in the lower back (p = 0.00), knee (p = 0.009), finger (p = 0.046), and wrist (p = 0.032). Additionally, work fatigue contributes to pain in the lower back (p = 0.018), shoulder (p = 0.018), thigh (p = 0.048), elbow (p = 0.001), knee (p = 0.022), and wrist (p = 0.022) during threshing¹⁰. Another study in Thailand indicated that compared to those working 7 h and above, the risk of musculoskeletal disorders during planting was lower among farmers working less hours during seedling activities (aPR = 0.76) and tasks like topping plants (aPR = 0.74)¹¹. The production activities of rice cultivation necessitate the extensive use of musculoskeletal systems and require the maintenance of inconvenient postures daily. In addition to the inconvenience of posture, rice cultivation is also associated with mud (field flooding), pathways (field edges), the use of unsafe bridges in transportation to and from the fields (often crossing canals and ditches), the use of heavy hand tools and others. This phenomenon renders rice farmers more vulnerable to accidents and injuries, which has been corroborated in numerous prior studies^12,13,14,15. The accumulated evidence demonstrates that farmers engaging in rice cultivation are at risk of occupational accidents, which can have short-term or long-term impacts on their health^13,16,17. Hence, the challenge ahead is to address methods to minimize occupational accidents in rice production. However, to date, evidence has been scarce about occupational accidents in the rice cultivation sector in Vietnam. Therefore, this study investigated the rate of agricultural occupational accidents among rice farmers and the factors related to this problem in Vietnam.

Ethical issues

This study was approved by the Institutional Review Board of Hanoi Medical University (Approval Number: 1054/GCN-HMUIRB, Project Code: TNLDLUA). Permission was also obtained from the local authorities to conduct the research. All participant data were anonymized and securely stored to ensure confidentiality and were used exclusively for research purposes. Participants were fully informed about the objectives and procedures of the study, and written informed consent was obtained prior to their participation.

Among the 1171 participating rice farmers, the average age was 59.10 ± 12.15 years, with the majority (58.3%) being 60 years or older. The gender distribution showed that there were more female farmers than male farmers. In terms of educational attainment, 76.5% of participants had an education level at or below the lower secondary level. Additionally, 44.4% of the farmers were the primary economic providers for their families. Regarding lifestyle habits, 47.4% of the participants reported engaging in daily physical exercise, while 7.7% reported smoking, and 15.8% reported consuming alcohol.

The proportion of individuals engaged in occupations other than rice production was 44.2%. The average number of years spent in the rice agricultural profession was 33.10 ± 13.92 years, with individuals spending an average of 4.87 ± 2.15 h daily engaging in this agrarian activity.

Results in Table 1 shows that 17.5% of rice farmers experienced occupational accidents in the past six months, with significant associations between accidents and factors such as age (χ² test, p = 0.004), education level (χ² test, p = 0.017), and daily exercise (χ² test, p = 0.008). Older farmers, particularly those aged 60 and above, were more likely to report accidents (20.6%), while farmers with lower education levels (below secondary school) and those who did not engage in daily exercise also faced higher risks (19.0% and 20.3%, respectively). Gender (χ² test, p = 0.270), smoking (χ² test, p = 0.533), and alcohol use (χ² test, p = 0.112) were not significantly associated with accidents, although current alcohol users showed a higher rate of accidents (22.7%). These findings suggest that physical fitness, education, and age might play important roles in occupational safety, underscoring the need for targeted interventions to reduce risks in vulnerable farmer populations.

The analysis of the causes of occupational accidents among rice farmers revealed significant differences in two key areas. Male farmers reported a significantly higher rate of accidents from carrying tasks (19.5%) compared to female farmers (5.7%) (χ² test, p = 0.002), possibly reflecting the heavier loads typically handled by men in rice farming. Additionally, machinery-related accidents were more common among male farmers (18.3%) compared to females (6.5%) (χ² test, p = 0.009), suggesting that men are more frequently involved in tasks requiring the operation of machinery. These findings point to specific tasks, such as carrying and machinery operation, as higher-risk activities for male farmers, indicating the need for targeted safety interventions for these tasks to reduce the risk of accidents. (Table 2)

The analysis of the characteristics of occupational accidents among rice farmers showed that 41.0% of farmers experienced three or more accidents, but there was no statistically significant difference between male and female farmers regarding the number of accidents (χ² test, p = 0.408). Injuries were mostly concentrated in the limbs, with 74.1% of accidents resulting in injuries to the arms or legs, again with no significant gender differences (χ² test, p = 0.696). Although female farmers reported slightly higher rates of multiple injuries (43.1%) compared to male farmers (37.8%), this was not statistically significant (χ² test, p = 0.408). The injured body parts also did not differ significantly between genders; for example, head, face, and neck injuries accounted for only 9.8% of cases, without a meaningful difference between males and females (χ² test, p = 0.631). These results suggest that the severity and ___location of injuries, as well as the frequency of accidents, are relatively similar between male and female farmers. However, the high proportion of farmers experiencing multiple injuries (28.3%) highlights the need for interventions focused on preventing recurrent accidents, especially in areas of the body most vulnerable during agricultural work. (Table 3)

Table 4 presents both univariable and multivariable logistic regression analyses to identify factors associated with occupational accidents among rice farmers. The key takeaway from the analysis is that age, gender, education level, daily exercise, alcohol use, and working hours are significant predictors of occupational accidents. Specifically, older age (aOR = 1.022, p = 0.002) and being female (aOR = 1.521, p = 0.028) were significantly associated with a higher risk of accidents, which may suggest that physical limitations due to aging and potentially different work responsibilities or ergonomic factors contribute to these risks. Farmers with lower educational attainment were also more likely to experience accidents (p = 0.018 in univariable analysis), possibly due to less awareness of safety practices. Lack of daily exercise was another significant factor (aOR = 1.497, p = 0.011), indicating that physical fitness could play a protective role in accident prevention. Additionally, current alcohol use was a significant predictor of accidents (aOR = 1.938, p = 0.006), suggesting that alcohol consumption impairs concentration and physical performance. Longer working hours were also associated with a higher accident risk (aOR = 1.092, p = 0.015), possibly due to fatigue.

Table 5 presents the treatment and consequences of occupational accidents among rice farmers, revealing several key findings. The majority of farmers (62.9%) reported receiving first aid after an accident, with no significant difference between male and female farmers (χ² test, p = 0.111). Notably, 76.0% of those who received first aid treated themselves, with self-administered aid being slightly more common among males (82.5%) than females (70.8%), though this difference was not statistically significant (χ² test, p = 0.125). Interestingly, a large portion of farmers did not seek further medical treatment after the accident, with 52.7% reporting no follow-up care. Among those who did receive treatment, district hospitals were the most common ___location (57.7%).

In terms of the impact on household economy, 43.9% of farmers reported a moderate influence of accidents, while 17.6% reported a significant financial burden. However, there were no significant gender differences in the economic impact (χ² test, p = 0.101). The average cost of treatment for an occupational accident was 1,241.12 thousand VND, with no significant difference between male and female farmers (p = 0.444, Mann-Whitney U test). These findings suggest that while many farmers manage their injuries through self-administered first aid, the lack of follow-up treatment could be a concern, especially for severe injuries. The financial burden on households also highlights the economic impact of occupational accidents, particularly for those reporting moderate to significant effects. These trends may reflect limited access to healthcare or a cultural preference for self-reliance in managing injuries among rice farmers.

Overall, the results reveal significant occupational risks for rice farmers, with factors such as age, gender, education, physical activity, and alcohol use being critical determinants of accident rates. Older and female farmers were found to be particularly vulnerable, potentially due to physical limitations and differing farming roles. Lower education levels were associated with higher accident rates, likely reflecting gaps in safety knowledge or training. Carrying heavy loads and machinery use were prominent causes of accidents, particularly for male farmers. Despite the frequency of accidents, many farmers relied on self-administered first aid, with a large proportion not seeking further medical treatment, raising concerns about access to adequate care. Additionally, accidents placed a moderate to significant economic burden on nearly half of the households. These findings underscore the need for targeted interventions, such as safety training and improved healthcare access, to reduce accident rates and mitigate the economic impact on rice farming communities.

This study found that rice farmers in our sample, particularly those who were older, female, or had lower education levels, experienced a high rate of occupational accidents. Factors such as not exercising daily, alcohol consumption, and longer working hours significantly increased the risk of accidents. Despite the high incidence of accidents, many farmers either self-administered first aid or did not receive any treatment. The accidents had a moderate impact on their families and incurred considerable costs. These findings highlight the need for targeted interventions to improve safety and health practices among rice farmers.

Our findings show that 17.5% of farmers experienced at least one workplace injury in the preceding six months, which is considerably lower than the reported 69.0% of farmers in Nepal who suffered injuries in the previous year¹⁸. This significant difference may be due to variations in farming practices, where Nepalese farmers often engage in more labor-intensive and hazardous manual work, potentially without adequate safety measures. In contrast, the outcome is more comparable to a prior study in Thailand, where 19.2% of farmers reported workplace injuries¹⁷. This similarity might reflect shared agricultural practices and challenges between Vietnam and Thailand, such as reliance on manual labor and exposure to similar risks. However, differences in safety regulations, enforcement, and the availability of personal protective equipment (PPE) could explain the slight variance between the countries. Additionally, cultural factors influencing safety awareness, risk perception, and reporting behaviors may also contribute to these discrepancies. In Vietnam, rice cultivation involves significant physical exertion and manual labor throughout various stages—soil preparation, sowing, planting, hand weeding, fertilizing, water management, pesticide application, harvesting, processing, and preservation^19,20. Farmers are exposed to hazards from agricultural machinery²¹, biological and chemical agents, and social and environmental stressors, which are consistent with the risks faced by farmers in other rice-producing countries like Thailand and Nepal. However, the extent of these risks may vary based on the level of mechanization and safety measures in place across different regions.

Numerous potential hazards were identified as contributing to occupational accidents among rice farmers, many of which are inherent to the agricultural practices involved in rice cultivation. Among these, the use of sharp tools such as hoes, sickles, and knives was a significant risk, with the most common cause of accidents being lacerations from sharp objects, consistent with findings from a study in Thailand, where 33% of injuries were due to such incidents²². Farmers rely heavily on these tools for soil preparation, planting, and harvesting, and accidents can easily occur due to improper handling or careless use. However, the implementation of safety measures to mitigate these risks faces several challenges. Financial constraints are a major barrier, as many farmers may not be able to afford protective equipment like gloves or specialized tools designed to minimize the risk of injury. Furthermore, there is often a lack of access to safety training programs that could educate farmers on proper tool usage and preventive strategies. In rural farming communities, safety protocols are often informal or non-existent, and there is limited awareness of occupational health risks. These factors, combined with the necessity to complete labor-intensive tasks under time pressure, contribute to a higher likelihood of accidents and injuries. Addressing these challenges requires not only making protective equipment more affordable and accessible but also providing widespread safety education tailored to the specific needs of rice farmers.

The allocation of tasks in rice farming often varies based on gender, with men and women traditionally assigned different roles. While it has been observed that women are often regarded as safer workers due to a lower incidence of work-related injuries compared to men, this is largely influenced by the specific tasks each gender performs²³. In our study, a notable difference between male and female farmers was observed in the incidence of injuries related to manual handling and machinery accidents, with men being more prone to these types of injuries. This can be attributed to societal roles, where men are typically responsible for physically demanding tasks such as operating heavy machinery, carrying heavy loads, or engaging in more hazardous activities, while women may focus on less physically demanding, though still labor-intensive, tasks such as planting, weeding, or hand-harvesting^23,24.

In comparison to findings from other countries, such as Japan, where a study reported a male-to-female ratio of 9:1 for machinery-related injuries, our results similarly highlight that men are at a higher risk for such injuries, though the ratios are less extreme²⁵. These differences may reflect cultural and regional variations in farming practices. In Japan, for instance, mechanization may be more advanced, with men taking on a greater share of the risky²⁵, machinery-intensive work, whereas in Vietnam, the division of labor might still involve more manual work for both genders. Access to resources, such as safety equipment or training, could also play a role in these disparities, with men perhaps having more opportunities or responsibilities to handle machinery, and therefore encountering more risks. However, women’s involvement in physically demanding tasks is not insignificant, and their potential for injury could increase with insufficient access to protective equipment or safety training. These gender-based differences suggest that interventions should be tailored to the specific risks faced by men and women in farming, emphasizing safe practices in machinery use for men and considering the ergonomic risks faced by women in repetitive manual tasks. Cultural and regional factors should also be taken into account when designing safety programs, as they can influence both the division of labor, and the types of risks encountered in farming environments.

The findings from our research indicate that rice farmers in Thai Binh province are exposed to a variety of occupational hazards during the production process. These risks align with previous studies, such as a study in Thailand that highlighted hand tractor-related injuries, where running over coconut shell debris was a common cause (33.1%)²⁶. The diversity of risks in rice farming is evident from our study, where 41.0% of farmers experienced occupational injuries three or more times, a notably higher incidence than the 12% reported in a survey conducted in the United States²⁷. The most frequently injured body parts were the limbs, with 74.1% of injuries affecting the hands and feet, a finding consistent with numerous other agricultural studies^28,29,30. Injuries to the limbs are common in rice cultivation due to the frequent use of sharp tools such as hoes, sickles, harvesters, knives, and saws, as well as the manual processing of raw materials, metal hammering, and wading through flooded fields. These tasks place farmers at high risk of cuts, abrasions, and other injuries. Unfortunately, hand and foot protection is often overlooked due to a combination of factors, including a lack of awareness about the risks, discomfort from wearing protective gear, or concerns that safety equipment might hinder work performance. To address these risks, preventive measures must be emphasized. Encouraging the use of proper protective gear, such as gloves and safety boots, is critical in reducing hand and foot injuries. Additionally, safety training programs could improve awareness of the risks associated with sharp tools and the importance of protective equipment. These programs should also highlight the ergonomic risks inherent in repetitive tasks and offer guidance on proper handling techniques to reduce the likelihood of strain injuries. By prioritizing the protection of the hands and feet, which are the most vulnerable body parts during agricultural tasks, farmers can significantly reduce the rate of injuries and improve overall safety in the rice farming process.

This study showed a higher incidence of occupational accidents among individuals aged 60 and older (20.6%), a finding consistent with a survey of South Korean farmers where the highest non-fatal agricultural work injury rate occurred in the 60–64 age group (21.24%)³¹. Elderly farmers in rice cultivation are more prone to accidents due to age-related factors such as declining health, reduced mobility, and diminishing physical capacity, which collectively increase their vulnerability to workplace accidents. However, research from the United States presents a contrasting picture, where younger farmers—especially males under 65—were found to be more at risk of injury³². In the U.S., factors such as male gender, primary occupation in farming, longer working hours, and larger-scale farming operations were identified as risk factors for accidents.

These conflicting findings between countries may be explained by differences in farming practices, cultural attitudes toward aging, and access to healthcare^33,34. In South Korea and Vietnam, for example, elderly farmers often continue working well beyond traditional retirement age, possibly due to economic necessity or a lack of formal retirement plans. This prolonged involvement in physically demanding tasks despite reduced physical capacity may increase their susceptibility to injuries. In contrast, in the U.S., farmers might have more access to mechanized equipment, reducing the physical strain of farming but introducing new risks associated with operating machinery. Moreover, in countries like the U.S., younger farmers often work on larger, more commercialized farms that might involve more complex and hazardous tasks, thus elevating their risk of injury.

Cultural attitudes also play a role, as older farmers in some regions may be more reluctant to delegate labor-intensive tasks or seek assistance, increasing their risk of accidents^35,36. Additionally, access to healthcare and preventive services may differ, with elderly farmers in Vietnam and South Korea possibly having limited access to medical care or safety training, exacerbating their risk of injury. In contrast, U.S. farmers may have better access to healthcare, safety programs, and technology that mitigate risks. These factors suggest that age-related risks in farming are context-dependent, and addressing these risks will require targeted interventions tailored to the specific practices, resources, and cultural attitudes of each region³⁷.

In our study, we found that alcohol consumption and lack of daily exercise were significant risk factors associated with a higher likelihood of occupational accidents among rice farmers. These findings align with a prior study in Ethiopia, where alcohol consumption was linked to common agricultural injuries³⁸. Regular physical exercise improves overall health, balance, flexibility, and endurance, helping farmers better manage the physically demanding tasks of agriculture and reducing injury risks. In contrast, alcohol consumption impairs concentration, reflexes, and decision-making abilities, increasing the likelihood of accidents, particularly when handling machinery or sharp tools. To address these risks, community-based health programs could be developed to promote healthy lifestyle changes among farmers. For example, public health initiatives could incorporate tailored campaigns that raise awareness about the dangers of alcohol consumption during work, while also encouraging regular physical activity to enhance farmers’ resilience to physical strain. These programs could integrate educational workshops, access to fitness resources, and local support networks to help reduce the prevalence of accidents linked to these lifestyle factors, ultimately contributing to a safer and healthier farming environment.

The time pressure from seasonal work often forces farmers to work extended hours each day and for more consecutive days per week, leading to increased stress and fatigue—key risk factors for occupational accidents. Extended working hours are widely acknowledged as a significant contributor to accidents in agriculture, as fatigue diminishes concentration and decision-making abilities³⁹. Our study found a clear correlation between the number of hours worked per day in rice cultivation and the incidence of occupational accidents. This pattern mirrors findings from research conducted in Japan, where long working hours were similarly linked to higher rates of injuries⁴⁰. In terms of first aid practices, our study revealed that only 62.9% of rice farmers received immediate first aid following an accident, with no significant gender differences. Notably, most injured individuals (76.0%) self-administered first aid, while only 47.3% sought further medical treatment. District hospitals were the most common ___location for treatment (57.7%). The widespread use of self-administered first aid suggests significant barriers to accessing proper medical care, potentially due to financial constraints, geographical isolation, or a lack of knowledge about the importance of professional treatment. A study from Karnataka, India, indicated that while many farmers had heard of first aid (76.7%) and understood its importance (80%), a substantial number believed that only a doctor should provide it, reflecting possible cultural attitudes toward formal medical care⁴¹. To improve these practices, targeted interventions are needed to increase first aid knowledge and accessibility. Community-based training programs could be established to educate farmers on basic first aid techniques, ensuring they are equipped to handle injuries more effectively in the field. Additionally, increasing awareness about the importance of seeking medical treatment after serious injuries could reduce the reliance on self-administered care. Mobile health units or improved access to local healthcare facilities could further reduce barriers, ensuring that farmers receive timely and appropriate care. By addressing these gaps in knowledge and access, it is possible to reduce the long-term impacts of occupational injuries on rice farmers and improve overall safety in the agricultural sector.

In our study, the average cost incurred by farmers for agricultural care and treatment of accidents was 1,241.12 ± 3,070.43 thousand VND (approximately 50 USD). While this may seem relatively low, it represents a significant financial burden for many farmers, especially those with lower incomes or limited access to resources. Furthermore, 17.6% of rice farmers reported that occupational accidents had a significant impact on their household economy. These costs can lead to financial strain, forcing farmers to divert income from essential needs such as food, education, or farm investment, which can in turn affect their long-term productivity and economic stability. In countries like Thailand, where similar agricultural practices are in place, the economic burden of occupational accidents in the agricultural sector was much higher, with 1,704,655 injuries in 2017 alone costing 36 million US dollars. These comparisons highlight the broader economic impact that occupational injuries can have on a national scale, especially in developing countries where agriculture is a major economic driver³². To alleviate this financial burden on farmers, policy interventions are crucial. Subsidized healthcare or insurance programs specifically for agricultural workers could help mitigate the costs associated with workplace injuries. Additionally, implementing community-based safety programs that provide training on accident prevention and first aid can reduce the frequency and severity of accidents. Governments could also offer financial support or compensation for farmers who are temporarily unable to work due to injuries, thus protecting their livelihoods during recovery. These strategies, combined with broader efforts to improve access to affordable healthcare, would help reduce the economic toll of occupational accidents on farmers and their families.

The findings of this study highlight several key measures to improve the occupational safety of rice farmers and suggest specific recommendations for policymakers, healthcare providers, and community leaders. Policymakers should develop and implement safety training programs tailored for farmers, focusing on hazard recognition, safe use of equipment, and first aid response. These programs can be delivered through agricultural cooperatives or local government initiatives to ensure widespread participation. In addition, policymakers should consider providing subsidies or financial incentives to make PPE, such as gloves, safety goggles, and helmets, more affordable and accessible to all farmers. Healthcare providers can play a critical role by offering routine occupational health screenings, providing injury prevention education, and equipping local clinics with the necessary tools to handle work-related injuries effectively. Collaborating with local agricultural communities, healthcare providers could also host workshops to improve farmers’ understanding of preventive health practices and the importance of PPE. Community leaders should advocate for regular equipment inspections and maintenance to prevent accidents caused by faulty or poorly maintained tools. Additionally, they can help foster a culture of safety by organizing community-based initiatives that encourage safer farming practices, such as rotating tasks to prevent fatigue and organizing workloads to minimize risks of collisions and overexertion. By focusing on these targeted interventions, stakeholders can significantly reduce occupational hazards and promote a safer working environment for rice farmers.

The strengths of this research lie in its practical exploration of rice production within the unique historical and cultural contexts of different regions, particularly in the northern region of Vietnam. The study’s novelty comes from its focus on the specific geographical context and characteristics of rice farmers, which have shaped the patterns of occupational injuries and highlighted opportunities for developing targeted strategies to reduce risks. By examining the types of accidents that occur within this distinct environment, the study offers valuable insights that are necessary for crafting recommendations tailored to the specific needs of each region. Moreover, the lack of prior research on occupational accidents in Vietnamese rice farming further underscores the importance of this study. However, there are limitations that should be considered when interpreting the findings. The reliance on self-reported data may introduce recall bias, as participants may not accurately remember or disclose the full details of their accidents. Additionally, the cross-sectional design limits the ability to draw causal relationships between risk factors and accidents, as it only captures data from a single point in time. These factors may affect the generalizability of the findings, particularly in regions with different farming practices or socioeconomic conditions. Future research should consider longitudinal studies to better assess causality and include more objective measures of injury data. Expanding the scope to other regions in Vietnam or internationally would also help to confirm the study’s findings and develop more comprehensive strategies for reducing occupational injuries in rice farming.

The research highlights that occupational accidents remain a significant issue among individuals involved in rice farming. Various factors contribute to the occurrence of these accidents, including gender, age, lack of regular physical activity, alcohol consumption, and extended working hours. Prioritizing preventive interventions for occupational accidents is essential to reducing the risks and improving both work efficiency and quality of life for this vulnerable population.

Study design and participants

A cross-sectional descriptive study was conducted in February 2024 in six communes across two rural districts of Thai Binh, Vietnam, to assess occupational accidents among rice farmers. The cross-sectional design was chosen as it allows for a snapshot of the current prevalence and risk factors associated with occupational accidents, aligning with the study’s objective of identifying immediate risks and areas for intervention in a specific population. The selection criteria for participants included: (1) being a farmer, (2) aged 18 and above, (3) residing in the study area and actively participating in rice cultivation for at least 12 months prior to the study, and (4) voluntary participation. While no explicit exclusion criteria were mentioned, it would be beneficial to clarify if individuals who do not meet the rice farming duration or age requirements were excluded, or if any other restrictions were applied.

The sample size calculation used the formula for estimating a population proportion, with p = 0.192 (based on the proportion of rice farmers experiencing occupational accidents from a previous study¹⁷), α = 0.05, and ε (relative precision) = 0.20. A design effect of 2 was used to account for potential clustering in the population, as rice farmers within communes may have similar exposures and risks. The 10% buffer added to the sample size accounts for potential dropouts or non-responses, a standard practice in survey-based studies to ensure sufficient statistical power and representation. The final sample size was 1171 rice farmers, which exceeds the calculated size of 890, further enhancing the study’s reliability.

A multi-stage random sampling approach was employed. First, two districts—Vu Thu and Kien Xuong—were randomly selected from a list of districts in Thai Binh. These districts were chosen due to their prominence in rice cultivation, making them representative of the rural farming population in the region. From there, three communes within each district were randomly selected. The first farmer was randomly chosen, and door-to-door inquiries continued until the desired sample size was reached in each commune. This method ensured a random and representative sample of rice farmers in the area. (Fig. 1).

Sampling approach.

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The study protocol was approved by the Institutional Review Board of Hanoi Medical University (Code: 1054/GCN-HMUIRB), and all methods were performed in accordance with relevant guidelines and regulations.

Data collection

The data collection team consisted of researchers, medical students from Thai Binh University of Medicine and Pharmacy, and healthcare staff from six commune health stations. To ensure consistency across all interviewers and maintain the quality of data collection, team members were assigned specific roles based on their expertise. Researchers oversaw the overall coordination and data integrity, while medical students and healthcare staff conducted interviews and facilitated communication with participants. All investigators underwent specialized training sessions led by experts, which covered topics such as interview techniques, communication skills, ethical considerations, and the proper use of the structured questionnaire. These training sessions lasted for two days and included practical exercises to simulate real-life interactions, ensuring the team was well-prepared to engage with participants effectively. Inter-rater reliability was tested through mock interviews, with supervisors reviewing the responses to ensure consistency and accuracy in data collection.

The structured questionnaire used for the study was pilot-tested to align with the cultural context and the specific circumstances of rice farmers. The pilot test involved a small group of farmers from the same region, and their feedback was instrumental in revising the questionnaire. For example, participants highlighted certain phrases or questions that were unclear or difficult to interpret, leading to adjustments in the language and structure of the questions. The sequencing of questions was also modified based on their feedback to ensure a logical flow that made it easier for farmers to respond comprehensively. This iterative process ensured that the final questionnaire was culturally appropriate and easy to understand, thereby improving the quality of the data collected during the actual study.

Variables

Our study involved several key variables:

• General information: This included demographic data such as age, gender (male/female), educational level (primary school and below/secondary school and above), and whether the participant was the primary household decision-maker (Yes/No).

• Health-related behaviors: Variables included smoking (Yes/No/Ever), alcohol consumption (Yes/No/Ever), and daily exercise (Yes/No). Daily exercise was defined as any physical activity done with regularity for at least 30 min per day, including walking, cycling, or manual labor tasks that elevated heart rate. For alcohol consumption, we further specified frequency (daily/weekly/occasionally) and quantity (number of drinks per occasion) to gain more insight into drinking behaviors.

• Characteristics of labor activity: We asked whether participants engaged in other occupational activities besides rice cultivation (Yes/No). Other labor characteristics included the number of years working in rice cultivation and the average number of hours worked per day in rice cultivation.

• Incidence of occupational accidents: This was self-reported by participants. Farmers were asked if they had experienced any accidents while planting rice (Yes/No) within the past 12 months. The types of accidents were categorized by cause (e.g., Falling, Carrying, Livestock, Machinery, Sharp objects, Traffic accidents, Exposure to sun/heat, Intoxication with plant protection chemicals - PPC). Additionally, participants reported the number of accidents they had experienced (1 time, 2 times, or 3 times or more) and the body parts affected (Head, face, neck/Limb/Body/Whole body). While the data was primarily self-reported, we cross-checked these reports with any available local health records for a subset of participants to increase data reliability.

• First aid and cost of occupational accidents: For first aid, participants were asked whether they administered first aid immediately after the accident (Yes/No) and what specific type of first aid was provided (e.g., wound dressing, splinting, cooling burns). The cost of the occupational accident was calculated by asking participants to report their direct medical cost. These estimates were gathered through participant self-reporting and, where applicable, cross-referenced with local clinic records for accuracy.

Statistical analysis

Data were cleaned and entered using Epidata 3.1 software. During the data cleaning process, we performed several key steps, including checking for missing values, identifying and addressing outliers, and verifying data consistency by cross-referencing with original survey records. Missing data were handled using listwise deletion to ensure the integrity of the dataset. IBM^® SPSS^® Statistics 22.0 (IBM Corp, Armonk, United States) was chosen for data analysis due to its robust capacity to handle a wide range of statistical procedures and ease of use for both univariate and multivariate analysis, particularly logistic regression. SPSS was well-suited to the large dataset and allowed for efficient data management and comprehensive statistical tests.

Continuous variables were assessed for normality using the Shapiro-Wilk test. For variables that did not meet the normality assumption, non-parametric tests such as the Mann-Whitney U test were employed. Categorical variables were compared using the χ² test or Fisher’s exact test when expected cell counts were low. These statistical tests were selected based on the type and distribution of the data, with the Mann-Whitney U test used for non-normally distributed continuous variables, and χ² and Fisher’s exact tests applied to categorical variables to account for the distribution and sample sizes. We did not make adjustments for multiple comparisons in this exploratory analysis, as the study aimed to identify potential risk factors for further investigation. However, we acknowledge the possibility of type I error due to multiple testing, and future studies may consider applying adjustments, such as the Bonferroni correction, to control for this.

Univariate and multivariate logistic regression analyses were conducted to evaluate factors related to occupational accidents among rice farmers. Independent variables included demographic characteristics, lifestyle habits, and agricultural labor activities. In the multivariate logistic regression, we used the stepwise backward elimination method to refine the model by removing variables that did not significantly contribute to the outcome. A significance level of p < 0.05 was applied throughout the analysis, a conventional threshold chosen to balance sensitivity and specificity. While we did not adjust for multiple testing in this initial analysis, this p-value cutoff allows for identifying significant associations that can inform future studies.