Interventions to reduce injuries among older workers in agriculture: A review of evaluated intervention projects

1 Introduction

Approximately 35 per cent of the global workforce is involved in agriculture, forestry, fishing and hunting [1]. At the same time, the number of older workers is increasing due to the demographic change with more elderly people [2–4]. Agricultural workers are already over-represented in the old age workforce and work more often than those in other occupations until older age [5–8].

Furthermore, there is a high incidence of work-related accidents and demands in agriculture and a number of studies highlight the importance of preventing injuries and promoting the health of older agricultural workers [9–13]. Farming consistently ranks as one of the highest injury risk work sectors [1, 14–16]. For example, according to ILO estimates, agriculture is among the most dangerous sectors in terms of fatal accidents, injuries and work-related ill health [1]. At least 170 000 agricultural workers worldwide are killed each year and the mortality rates have remained consistently high over the past decade. In addition, there is widespread under-reporting of injuries, occupational diseases and deaths, which means that the true picture of occupational safety and health (OSH) is likely to be worse. Elderly workers also seem to suffer a higher risk of injuries [17, 18]. Approximately 38 per cent of the general workforce who die from work-related injuries are 55 years or older [19, 20], but roughly 60 per cent of those who die from work-related injuries in agriculture are 55 years or older.

Agricultural workers are at risk from a wide variety of hazards, e.g. machinery, biological, chemical, dust, ergonomic, psychosocial and physical, as well as from long hours of work [1]. Poorly designed tools, difficult terrain and exposure combined with fatigue in older workers increase the risk of injuries. Although technological change has reduced the physical demands of agricultural work in some areas, it has introduced new risks, e.g. associated with the use of sophisticated machinery and the intensive use of chemicals such as pesticides without appropriate safety and health risk control measures, information or training [1].

It is a known fact that functional health decreases in many people as they grow older [21–25]. From 40 years of age, anatomical and physiological systems are declining, as is the interaction between brain, sensory organs, locomotive organs and circulatory organs [26, 27]. The prevalence of chronic pain, problems with hearing and eyesight, and also slower reaction times and work-related exhaustion seem to increase with age [28–30]. This all contributes to older people being at higher risk of injury than middle-aged and young people [18]. Older agricultural workers also seem to take longer to recover and go back to work after an accident [31]. Since functional ageing affects the body and mind of workers in an ageing workforce, many more workplaces will have to be age-adapted [9–13, 32–37].

The overall objective of this study was to extend knowledge about how to decrease risks and work injuries among agricultural workers aged 55 years and older through a systematic review of evaluations of previous intervention programmes with this aim.

2 Materials and methods

The method used was a systematic literature review, performed in several steps in accordance with the literature review guidelines in “Cochrane Handbook for Systematic Reviews of Interventions“ [38]. First, a list of criteria was drawn up with the objective of increasing the validity and limiting the search to the articles most relevant to the topic under investigation. Since the aim of this study was to analyse evaluated health and safety intervention studies on older workers in agriculture, the criteria were set to achieve this aim. The search was limited to articles published from 2000 onwards because older interventions were considered less relevant in light of the fast technical and organisational changes occurring in agriculture. The definition of older workers as 55 years and older was because that is a general age definition of an older worker in research [4].

The criteria for inclusion of articles in the literature review were:

Evaluated intervention project to reduce risks and prevent injuries

Literature searches were conducted in the following electronic databases: Medline, PubMed, Web of Knowledge, Scoop, Google Scholar, Cochrane Library and Science Direct, in order to locate evaluations of intervention and prevention projects targeting older workers in agriculture. Relevant articles were then identified in seven steps. First, a search for articles was carried out in each of the databases using the following seven different key words in various combinations: Older worker, Intervention, Health prevention, Health promotion, Age management, Farm, Agriculture. This resulted in a total of 2 229 289 articles. However, most articles did not meet the criteria set and had no relevance for this literature review. For example, the key word “Agriculture” led to many articles on crops, buildings and clean water. A number of articles also turned up many times in the application of different key word combinations and while searching various databases. Therefore the articles were sorted in order of relevance and those articles not addressing the topic of this literature review and duplicates were removed (Fig. 1).

3 Results of the search

A total of 2229 references were reviewed in order of relevance to the topic of this literature review. From these, 178 articles were selected by relevance and combination of key words and titles for a more detailed review. In the next step, after reading all the abstracts, summaries and methods, 29 articles were identified as having potential to be included in this review of evaluated intervention projects to reduce injuries among agricultural workers aged 55 years and older. Careful reading and examination of these articles was performed to determine whether they met all four criteria established for inclusion. However, this revealed that only three studies followed the inclusion criteria and could be included in the review and the remaining 26 studies were excluded.

4 Included studies

Of the three intervention studies that had the aim of reducing injury among older workers in agriculture, and were thus included in this review, two were related to general risk assessment and awareness training, i.e. lectures and workshops to reduce the risk of various types of injuries. These two articles concerned the FarmSafe Programme in New Zealand [39] and the Agricultural Health and Safety Network (AHSN) in Saskatoon, Canada [40]. The third article evaluated the effect of an information campaign to increase the use of roll-bars on tractors in the U.S. [41].

The FarmSafe Programme in New Zealand was directed at all farmers and people working with sheep, dairy and beef production on farms [39]. The intervention was carried out by the FarmSafe Consortium, including the Agriculture Industry Training Organisation (AgITO), Telford Rural Polytechnic (Telford), Agriculture NZ (a private training company) and the Injury Prevention Research Unit at the University of Otago. The aim of the study was to present findings from implementation of the intervention. The participants in the intervention were 6341 people working in agriculture in 2003. These participated in 350 workshops that presented e.g. statistics on farm accidents and causes of injuries in agriculture and “farm walks” with risk identification in order to eliminate risks and increase safety on farms. The programme also included a special information package delivered through television and magazine articles with the aim of spreading information about risk and safety in agriculture.

The evaluation article concluded that the intervention was successful in terms of farmer participation. However, it also noted that it was more difficult to reach older farmers and that people aged 55 and older had a much lower participation rate than younger people. Another shortcoming of the study was that it only described workshop participation rates and not the impact of the workshops and information activities on work injury rates among farmers and the participants’ attitude to safety and risk in agriculture. The evaluation was therefore exclusively on the number of participants and not on the effect of the intervention itself and from the text it was impossible to determine whether the intervention actually reduced accidents and injuries in agriculture and to older farm workers.

The Agricultural Health and Safety Network (AHSN) in Saskatoon, Canada, arranged 112 intervention efforts [40]. The intervention programme was developed in collaboration between active farmers and the Centre for Agricultural Medicine, University of Saskatchewan. The objective of the article was to evaluate whether the educational interventions by the AHSN programme were associated with observable differences in farm safety practices, physical farm hazards or farm-related injury outcomes.

The intervention had a pedagogic approach and raised various questions about security on the farm. These included educational interventions on farm safety issues: tractor safety (roll-over protection, extra rider injuries, run-over protection, jump starting), farm machinery safety (harvesting equipment, machinery guards, power take-off devices, all-terrain hazards), non-machinery hazards (falls, large animals, farm structures and buildings, power lines), burden of farm injury (statistical summaries, Impact of injury on farm families), personal and farm protection (emergency preparedness, farm safety audits/modules, hearing) and special populations at risk (children, young workers, older workers).

The subject evaluated in the study was the effect of AHSN activities on risk and injury in agriculture in 50 rural municipalities. The intervention included three groups: one which participated in AHSN for more than 8 years, one which participated in AHSN for 8 years or less and one which did not participate in AHSN. In the evaluation, participants were asked to complete a questionnaire about their farm safety, physical injuries and accidents that occurred on the farm. Adult key informants from 2386 farms responded. To evaluate the intervention results, the three groups were compared.

The results showed that training efforts in the AHSN programme were not associated with observable differences between the three groups in farm safety practices, physical farm hazards or incidence of agriculture-related physical injuries and accidents. A limitation pointed out in the article that could have affected the results was the impossibility of conducting a randomised controlled trial to test the relative effectiveness of AHSN. For example, promotional information material included a national farm safety brochure that was distributed to all farms during the project period.

A shortcoming of the evaluation in terms of the objectives of the present review was that it only described the effect to which the intervention project had contributed in general, and not whether there was any statistically significant variation between different groups in agriculture, e.g. younger and older farmers.

The American Society of Agricultural and Biological Engineers (ASABE) started an information campaign in the U.S. in 1993 to increase the use of roll-bars, i.e. Rollover Protective Structure (ROPS), on existing tractors and introduce ROPS as standard on new tractors, and thus reduce the mortality rate from tractor overturns [41]. The article evaluated the effect of the information campaign and the introduction of ROPS as standard on tractors through statistical analysis of a survey in which farmers were asked whether their tractors were equipped with roll-bars. The data were compiled by the National Institute of Occupational Safety and Health (NIOSH), which surveyed approximately 15 000 farm operators on the use of ROPS in 1993, 2001 and 2004. The results showed increased use of ROPS on tractors over time, i.e. 37% in 1993, 42% in 2001 and 46% in 2004. The results also showed that it was mostly farmers aged 65 years and older who still had tractors without ROPS, or farmers with lower farm income. The evaluation stated that the increase in ROPS use was not satisfactory to decrease the rate of tractor overturn deaths on farms. It also suggested that incentive programmes should target older agricultural workers and low-income farms to increase ROPS use on tractors. Despite the increased use of ROPS, the authors concluded that the use was not yet comparable to that in Europe. However, the results were described as being useful for future targeted information campaigns and interventions. As regards the objectives of the present review, it should be noted that this evaluation was not about the effect on injury incidence, but only about the use of the technical equipment reported in earlier studies to reduce injuries.

5 Excluded studies

In the final scrutiny of the 29 articles selected for review, it emerged only after reading the full text that 26 of these did not actually meet the inclusion criteria. The criterion “evaluated” was particularly problematic. Many studies described development of models for interventions or were study protocols of ongoing interventions and did not describe the outcome or results of an intervention, which was the topic of interest in this review [42–58]. Other reasons for exclusion were that the intervention did not include a description of the participants’ age, or excluded older workers [42, 59–61], or that it did not describe agricultural workers [49–51, 53–55,61, 66].

6 Discussion

In order to obtain better knowledge of older workers in agriculture, this paper reviewed published articles presenting evaluations of past interventions intended to decrease risks and work injuries among agricultural workers aged 55 years and older. This is interesting because working on farms and older workers are both correlated with a higher proportion of work-related injuries and death [5–8, 36]. However, the articles that met the strict criteria for this review did not report any marked injury decrease among older agricultural workers following the interventions. There seems to be a situation whereby many articles and statistics over the years and around the world describe injuries in agriculture and among older workers, but few scientific publicationsevaluate intervention programmes to reduce the problem. It is perhaps easier to measure and research the problem and suggest recommendations than to actually make an intervention and conduct a successful evaluation [68].

An extensive literature search revealed that there were few intervention studies focusing on injury prevention among older workers in agriculture. Application of three strict selection criteria for this review (evaluated intervention projects to prevent injuries; participants aged 55 years and older; and working in agriculture) resulted in only three articles that met the criteria. Earlier review studies have pointed out the great shortage of relevant studies regarding interventions to prevent injuries in agriculture (69-70) and of interventions promoting health and safety for older workers (71–73). Therefore the lack of intervention studies that included both older workers and injury prevention in agriculture was not a surprise. An additional problem in the present review was finding any actual evaluations showing an outcome and results from the intervention. It is important to rectify these shortages in order to bring about change.

The inclusion criteria in the present study were based on research quality labelling and a possible limitation is that the article had to be published in a scientific journal searchable in an electronic database. There could also be more or less successfully implemented interventions in practice, but not published in scientific journals, and therefore not included in this review. That may have excluded some evaluations of intervention studies. It was also important that the interventions were evaluated and that the outcome was described in the articles. This criterion was set to include evaluations of whether the intervention design was successful or not. A study protocol or a description of an intervention without an evaluation says nothing about the outcome and was thus not relevant for this review. Furthermore, restricting the search to articles published from the year 2000, because older interventions were considered less relevant in light of the fast technical and organisational changes occurring in agriculture, may have excluded some material.

The three intervention studies that met the inclusion criteria appeared to be solid, well-executed and successfully implemented [39–41]. However, the evaluation of the interventions could not show an injury-reducing effect for older agricultural workers. In addition, the intervention evaluations referred to older workers, compared with younger age groups, as being less likely to: participate voluntarily in health and safety intervention programmes; be aware of safety practices in their tasks; and use safety equipment such as ROPS. However, there are some factors to consider in the intervention design. It has been demonstrated that older people learn to remember things in a different way than when they were younger [74–76]. There is sometimes a misunderstanding and age discriminating descriptions that older people cannot or is not interested in learning new things [77–79]. Though, this is not an excuse for not implement interventions to this specifically risk exposed group. The interventions must instead be designed to meet the needs of older workers. It takes a longer time for older people to structure and organise new information in a cognitive way, which affects the time they take to learn new things [74, 75]. On the other hand, if the new knowledge is linked to the existing knowledge of older people, they can learn faster than young people. In fact, the actual potential to learn new things in old age is mostly affected by the individual’s own belief about their potential to learn and if they want to make a change [76]. The design of interventions needs to include these aspects about older people if they are to be successful. Repeating information, continuing education and pedagogic methods such as “learning by doing” seem to be a better way to teach new things and increase injury awareness among older workers than a one-off or short-term information campaign [6, 80]. Furthermore, the participation among elderly people is lower than among younger workers [39–41], so approaches to attract older workers need to be considered in the intervention design. Addressing a message directly to people in a special target group makes those people feel involved and increases their willingness to participate in interventions [80], in this case older workers in agriculture.

The design of approaches to evaluate interventions is another important question to consider. This is because intervention studies in general can have a problem identifying an effect and also determining whether the effect was an outcome of the preceding intervention or not [68, 81]. The three articles reviewed here used three different evaluation designs. Two actually evaluated the effect of the intervention: one assessed the effect in three groups with different levels of exposure to the intervention programme [40], and one examined the effect on the whole study population of changes in the use of risk-reducing equipment over time [41]. The third study evaluated the participation rates in the intervention, and not the effect of the programme on the participants’health and injuries or use of risk-reducing equipment [39]. Exchanges of information between people and in the general media increase the possible effect, but decrease the actual difference in exposure between those considered “exposed” and those considered “not exposed” in the evaluation. One example is an intervention with rice farmers in Thailand to empower them to protect their health and prevent occupational health hazards [65]. In the third year of the intervention, the researchers found that new networks of farmers and student-teachers had started by themselves in the surroundings and were using the intervention’s health promotion model for occupational health and safety. This could also be one reason why AHSN [40] did not find any significant effect on comparing the outcome between groups in its evaluation. People live together in society and the design of an intervention is complicated because people cannot be isolated as in a laboratory experiment. The aim of an intervention is also to spread information to people and propose changes in attitudes and behaviour. Successful information campaigns result in increased communication and informal information spreading in the community. Making a difference, e.g. decreasing health problems, is the main goal of starting an intervention. However, general spread of the information is unhelpful and could be a problem if the evaluation is designed to measure the effect of the intervention in different exposure groups.

The effectiveness of an intervention is measured by an evaluation method. Deciding how and what to measure in the evaluation is important for the validity of the intervention study [54, 80]. For example, reporting how many participants an intervention includes is not a valid measure of the effectiveness of the intervention if the aim is actually to reduce injuries among older agricultural workers. This lowers the validity of the study because it measures something else, and the effectiveness in reducing injuries among older agricultural workers cannot be stated based on that evaluation. However, measuring the number of participants is a good way to study the interest in making attitude and behavioural changes, as in the FarmSafe Programme in New Zealand [39], but the problem is that such evaluations do not show whether the participants then change their attitude and behaviour and whether the incidence of injury is decreased. The effect of an intervention programme aiming to change attitudes and behaviour is longitudinal, and therefore an evaluation such as that in the article about ROPS implementation in the total study population [41] could be a successful design. However, that study included no information and no control about whether those included in the evaluation actually took part in the intervention or whether the use of ROPS decreases mortality on farms. The organisation funding a research project often wants a result (often a good one) after a shorter period than ten years. The design used in intervention evaluations in all three articles reviewed [39–41] of measuring the effect in different directions seems therefore to be an interesting suggestion. Evaluation of successful intervention designs could be a topic for a further review study. The problem within an intervention study is often measuring the effect, as the study population and control population need to be similar but cannot be isolated from each other as in a laboratory experiment [42, 48]. Designing significant evaluation approaches for intervention projects therefore needs to be further researched, e.g. design of process evaluations, effect evaluations, etc.

This extensive literature search also found very few intervention studies regarding injury prevention to older agricultural workers published in scientific journals. Designing an intervention study and measuring the real outcome is complicated. However, the importance of interventions to reduce the gap between knowledge of a health or injury problem and making a practical and sustainable change through implementation in practice need to be highlighted in the research society and among research funding organisations. It is important to spread knowledge on initiatives undertaken, successfully or not, in order to increase the possibility to reduce work-related injuries in agriculture and to older workers. To achieve this, it is important to carry out more scientific evaluations of interventions and publish the results in readily available form. The results from past intervention programmes can be applied to spread new knowledge, bring about change and reduce injuries among older workers.

7 Conclusions

The most important findings in this review are the marked lack of injury decrease among older agricultural workers brought about by the interventions evaluated in the literature and the shortage of scientific publications on the subject. An important issue for a sustainable society is reducing injuries among one of the most vulnerable work groups, older workers, in one of the most dangerous work places, agriculture. Based on the results of this review,methods to achieve this need to be identified, refined and widely circulated. The evaluations reviewed were generally successful, but did not demonstrate any significant recognised or confirmed injury-reducing effect among older agricultural workers who participated in an intervention. Instead, the evaluations found that older farmers were less likely than their younger counterparts to participate voluntarily in health and safety intervention programmes; to apply new safety practices in their tasks after the intervention; or to use safety equipment such as tractor roll-bars after receiving safety information. Reducing work-related injuries among older agricultural workers seems to be a great challenge and suitable intervention and evaluation methods need to be formulated.

Conflict of interest

The author has no conflict of interest to report.