Pre-Employment physical capacity testing as a predictor of musculoskeletal injury in Victorian paramedics

1 Introduction

Workplace injuries place a significant physical, social and financial burden on organisations internationally [1]. With estimated economic cost of work related injuries in Australia being in excess of AUD$60 billion dollars per annum, these financial stressors imposed on organisations by way of lost work time, the cost of replacement employees, high insurance premiums and compensation claims continue to highlight the need for significant reduction in the occurrence of workplace injuries [2].

Implementation strategies by Federal and State government organisations, such as Work Safe Victoria awareness advertising have targeted campaigns highlighting a variety of issues from workplace bullying to musculoskeletal injuries, and the most recent It doesn’t hurt to speak up, young workers promotion [3]. Individual organisations have also been targeted by state government run Occupational Health and Safety (OHS) departments to decrease work related injuries, particularly in areas relating to manual handling, aiming to reduce the occurrence of musculoskeletal injuries. Despite this, the rate of musculoskeletal injury across the Australian workforce remained at 12.2 serious injury claims per 1000 employees during the 2010-11 financial year [4].

Whilst the range of injuries sustained is broad, the Safe Work Australia’s annual report for 2010–2011 identified that 42 percent of all serious claims were the result of sprain and strain injuries. Of all the serious injury claims lodged during this period, manual handling was reported as the mechanism of injury for 32 percent [4]. These statistics are reflective of the injury rates of Australia’s population during the midpoint of the study period.

The emergency health care sector is inherently linked and represented in these statistics in two keys areas; paramedics provide emergency management of these types of acute injury, and paramedics are simultaneously being subject to heightened risk of sustaining similar injuries as a direct consequence of providing care to people requiring prehospital emergency care. This study aimed to identify the type of musculoskeletal injury and the affected area of the body. Further this study aimed to determine if there was a relationship between pre-employment physical capacity testing scores and risk of workplace musculoskeletal injury within the paramedic industry.

Internationally the cost of workplace injuries and illness continues to have a significant financial impact on governments. An annual report by the Health and Safety Executive in Great Britain reported that the total cost to Great Britain due to workplace fatalities and self-reported injuries and ill health during the period 2010–2011 was estimated at GBP£13.8 billion (AUD$24 billion), of which an estimated GBP£5.4 billion (AUD$9.4 billion) was associated with workplace injury including fatalities. This national expenditure includes costs associated with loss of earnings to individuals; payment of benefits; medical treatment and rehabilitation costs, and associated administrative and legal costs [5].

Workplace injuries and illness span the globe and a similar study within the United States of America, reported the total estimated cost of occupational injury and illness in 2007 was approximately US$250 billion (AUD$271 billion) compared to a cost of US$217 billion (AUD$230 billion) fifteen years earlier in 1992 [6]. Of this reported US$250 billion in 2007, 77%was attributed to occupational injuries.

Australia’s economic cost related to workplace injury and illness has been reported by Safe Work as being in excess of AUD$60 billion per annum, representing 4.8%of Gross Domestic Product (GDP). Work-related injuries accounted for AUD$30,700 billion (51%) of this total Australian economic cost in 2008–2009 [2]. These figures represent the total financial impact and include the costs incurred by the employer, the worker and the community when an employee is injured or suffers a work-related illness. Notably over one third of both the total economic cost, and the total number of reported cases of injury, were associated with manual handling [2].

The work of a paramedic is characterized by unplanned patient care that may occur in any location from residential through to industrial or the public domain. Whilst locale for work varies tremendously in any given “callout” the EMS professionals level of physical activity can also be highly variable; there can be periods of sedentary activity such as when a paramedic is operating a motor vehicle, waiting to admit a patient at hospital for a sustained period or simply waiting for the emergency call out and the next case. Conversely, whilst administering patient care there are often short periods of high level physical activity, often coupled with repetitive or heavy manual handling tasks. Performing Cardiopulmonary Resuscitation (CPR) or extricating a patient out of a motor vehicle accident are examples to illustrate this point. The impact of these activities on a paramedic may be confounded by the inherent level of fitness of the paramedic [7, 8]. Some research has been conducted that attempts to quantify this. Gamble and colleagues evaluated physical fitness levels of Belfast ambulance service staff, and the physiological demands of their accident and emergency duties [9]. This study consisted of 91 male and 11 female volunteer participants (46%of the total ambulance service staff) in the geographical area in which the study was performed. Each participant was assessed for height, weight, trunk flexibility and hand grip strength. Body mass index (BMI) was calculated from this data. Female staff averaged lower hand-grip strength but higher trunk flexibility. A group of twenty voluntary male participants completed further, more rigorous testing to validate the study from this group, eight participants agreed to undergo assessment of accident and emergency duties including CPR and chair carrying. These two simulated work duties raised heart rates of the eight participants above anaerobic threshold values for periods of up to 11 minutes [9]. This study highlighted the physical nature of the tasks required of paramedics and the need for high standards of physical fitness. In summary, multiple studies report that periods of intermittent high physical demand undertaking activities like CPR, patient extrication and equipment carrying correlate to an increase in the risk of workplace injury, particularly musculoskeletal injury for paramedics [7, 9–12].

2 Methods

A retrospective case series review was conducted over a five-year period 2008 to 2015, using data obtained from an Australian pre-hospital emergency care provider (Ambulance Victoria). Pre-employment physical capacity testing (PEPCT) data and workplace injury (WI) manual handling data were obtained from Ambulance Victoria (AV), enabling comparison and analysis of two distinct data sets. All data was de-identified by AV prior to delivery to the investigators, and each data set matched using commencement date of employment, date of birth and gender of employee.

The PEPCT data represented a total score out of 25 for each individual paramedic, with a minimum score of 13 required to be considered for employment. Each score was separated into five areas of assessment (lumbar flexibility, body composition, cardiovascular performance, upper body strength, and abdominal strength.

The WI data included employee demographics such as age, gender, commencement date of employment, shift (work period) details, qualification level attained, as well as data pertaining to injury sustained by the paramedic, including type of injury and area of the body injured. The WI data included postcode which allowed the investigators to identify where the paramedic worked when they sustained the injury. These data were further classified into metro and rural regions using the AV rural versus metro boundary classification.

All paramedic employees were included for analysis if they were employed by AV during the study period, and had completed the PEPCT testing as part of their pre-employment screening. Case data was excluded if the injury reported was identified at any stage as other than musculoskeletal in nature resulting from manual handling.

In 2013, Legge et al. reported a 20.2%injury rate amongst 600 coal miners. Based on the work by Legge and colleagues, this study analyzed the records of 538 participants. This sample size allowed enough power to demonstrate a similar change in injury rate of 20%(alpha 0.05, power 0.8). Statistical power was calculated using G ^*power release 3.1.9. Frequency tables and descriptive statistics will be used to report demographic data. Descriptive statistics were used to report demographic data, odds ratios used to report potential links between PEPCT scores and subsequent paramedic injury, and logistic regression used to identify participant factors as predictors of musculoskeletal injury.

This study was granted ethics approval from Victoria University HREC, (HRE15084) and AV Research Governance Committee.

3 Results

During the study period (January 1, 2008, to June 30, 2015) a total of 538 paramedics were included for analysis and the mean age for the sample was 28.5 (SD = 6.1) years. The mean age of the sample for female participants was 27.6 (SD 6.2) years and for male participants was 29.4 (SD 7.8) years. The sample included a total of 285 (53.0%) females. Further demographic detail can be found in Table 1 which includes time in employment, region of employment and paramedic qualification.

Of the total participants in the study, n = 25 (8.8%) of females were injured compared to n = 9 (3.6%) males. Of the injured sample, this study identified more females (73.5%) were injured than males (26.5%). The female to male injured ration is 2.78:1 (Table 1).

During the study period, 34 paramedics of the sample reported a workplace musculoskeletal injury from manual handling, with the mean time to injury from commencement of employment being 395.4 days (SD 516.2). No difference in mean time to injury between the genders was found, with females mean time to injury being 447.1 days and males mean time to injury being 251.9 days (p = 0.34). Further, there was no significant difference in time to injury data between males and female when region of employment was analysed (p = 0.41) The percentage of injury sustained in the rural versus the metropolitan regions differed with 29.4%of injuries occurring in the rural work location and 70.6%occurring in the metropolitan region. Specific details of types and region of injury are detailed in Table 2.

Further analysis of employment region revealed no differences in type of injury incurred nor the area of the body injured between the two genders. Table 2 provides a summary of this analysis. Additionally, as the total number of injuries for the type and area of the body injured were small, no significant relationships could be determined.

More females reported being injured overall than males in both metro n = 16 (47.1%) versus n = 8 (23.5%) and rural n = 9 (23.5%) and n = 1 (2.9%) regions, respectively. This injury data is reported in Table 2.

Mean total PEPCT score for the entire sample was 19.1 (SD 2.9) out of a total of 25, while for those reporting injuries it was 18.3 (SD 2.6) out of 25. The mean difference for those who reported injury compared to non-inured was 0.8 (95%CI –0.2 to 1.8) out of a total of 25 for the PECPT score and was not statistically significant (p = 0.1).

Table 3 details reported paramedic injuries linked to specific elements of PEPCT and score achieved. A total of 9 males and 22 females reported injury during the study period. Given the small number of injuries reported in the study sample and thus low n values in the individual components of the PEPCT, there was no statistical significance detected in the scores for the injured versus the non-injured participants in the study sample. The mean PEPCT score for the lumbar area in injured (4.74 (SD 0.99)) versus in non-injured (4.74 (0.88)) participants were not significantly different (p = 0.976). These data are reported in Table 2.

With respect to scores of the individual element of the PEPCT, body composition scores for females ranged from 0–4 out 5 and males ranged from 3–5 out of 5 in the injured sample. (Table 3). Thirty-one (91.2%), 15 (44.1%) and 22 (64.7%) of injured participants scored 5 out of 5 in the PEPCT for lumbar, upper body and abdominal strength, respectively (Table 3).

Table 4 reports paramedic workplace musculoskeletal injury type linked to specific elements of PEPCT testing and score achieved. There were no significant differences identified in the types of musculoskeletal injury sustained nor area of body injured between males and female participants in metro or rural locations in the sample.

This study has provided the first analysis of musculoskeletal injury data associated with the provision of prehospital emergency care by Victorian paramedics with particular focus on the pre-employment physical capacity test (PEPCT) as a predictor for musculoskeletal injury resulting from manual handling in this participant group. The PEPCT test utilised by AV to assist in selection of suitable employees has not to date been subjected to examination within a clinical study, however this type of testing has been utilised widely across a number of industries and fields [20–23]. Notably, injured female paramedics are disproportionately represented within the current findings, with analysis revealing that females are more than 2.5 times likely to sustain a musculoskeletal injury exceeding reports in previous findings [13–17]. Of the total participants in the study, n = 25 (8.8%) of females were injured compared to n = 9 (3.6%) males. Of the injured sample, this study identified more females (73.5%) were injured than males (26.5%). The higher number of injured females compared to males in this current study is consistent with previous studies that identified women, independent of any other factor, were at an increased risk (of up to two times) of workplace injury in such fields as paramedic practice, sport, the military, and nursing [13–17]. Whilst no conclusion as to cause for their increased risk of injury was identified in the research, we postulate that this may be due to a range of factors including stature, build and muscle mass of females compared to males [12]. Additionally, a greater proportion of injury in female paramedics reported in the current data may be at least partly attributed to the increased likelihood of females reporting injury compared to their male counterparts. In the general population, it has been clearly documented that females are more likely to utilize healthcare services compared to males [14] and thus report injury.

Of interest in the current data is the percentage of injury sustained in the rural versus the metropolitan regions, with 29.4%of injuries occurring in the rural work location and 70.6%occurring in the metropolitan region. Why there is a proportional difference within the data between metropolitan and regional injuries is unclear but the data revealed one single male reported injury in rural Victoria during the study period. This may be related specifically to workload and subsequent increase in risk of injury. It this may be result of the variation in volume of call outs or patient attendance in by paramedics in busy metropolitan areas when compared to those of their less busy rural colleagues as has been reported in other studies [15, 18]. A greater volume of work and longer work hours may lead to decreased rest time or increased overtime leading to fatigue or risk-taking work behaviors for example. Fatigue has been reported as a risk factor for injury in other fields of work [4]. Further, reporting of injury rates may potentially vary between regions due to workplace culture and practice. There is currently no research in this area.

Musculoskeletal injuries of the back featured prominently within the data, accounting for 55.8%of all the injuries during the data collection period. Whilst not determinable from the current data, this is likely attributable to the industry requirement that lifting of patients (i.e. heavy objects) is a major feature of paramedic work.

Additionally, the data shows that female sustained more back injury compared to males working in the metro region. This data whilst not significant is consistent with previous studies that identified women are more at risk of workplace injury in such fields as paramedic practice, sport, the military, and nursing [13–17]. Whether there is disparity between metropolitan and regional injury rates is unclear within the data and may be due to the small sample size. Previous authors have reported there are differences and that these may be related specifically to workload (and subsequent increase in risk due to volume) [15, 18].

The investigators had prior to the study commencing, hypothesized that injury rates would likely be higher amongst longer serving (and hence older) paramedics whose fitness level may have declined. However, contrary to previous studies, the injury rate was highest among paramedics within the first three years of employment, with those under four years of service most likely to suffer musculoskeletal injury [17, 19]. Whilst beyond the scope of this study, these investigators postulate that different work tasks may be associated with different levels of experience. In general terms, experience tends to be linked to length of time in a job and thus by default, increased age within these fields and conceivably the nature of duties and work activities may play a significant role in injury risk [17].

The PEPCT is utilised by AV to assist in selection of suitable employees. It has been reported that in order to progress to recruitment, a candidate must achieve a minimum of 13/25 in the PEPCT although no granularity with respect to the requirements for minimum individual component scores is available. However, this type of testing has been utilised widely across a number of industries and fields [20–23]. The results identified no significant difference between PEPCT scores from those paramedics injured or not injured in the workplace during the study period. This is contrary to previous studies conducted in sport, mining and military settings [20–22], however supports a study that found no correlation between injury amongst United States of America (USA) firefighters and pre-employment physical testing [19].

In examining specific elements of the PEPCT to identify potential predictive scores, it was observed that for body composition, the PEPCT scores for females in particular were spread across the range of values of zero through to four out of five, whereas for the injured males, the scores fell within the range of one to three out of five (Table 3). Interestingly participants who scored highest in the PEPCT for lumbar, upper body and abdominal strength components were injured at a greater rate.

The findings of this research may give rise to the development of new injury prevention strategies and programs. Particular focus on injury prevention and manual handling training should be considered for the key “at risk” groups that have been identified being females and those newly employed as paramedics.

Additionally, the results of this study may be used to instigate a further review of the newly implemented AV PEPCT. In particular, an analysis of the impact that the removal of the body composition measurement, should be considered, given it has been removed from the new test.

5 Limitations

The retrospective data analysis method used in this study intrinsically challenges the ability of the researchers to elicit more detail than is recorded within the data, and this may have inhibited identification of other factors affecting paramedic workplace injury. It is also not clear from the data if underreporting of injuries (due to the self-reporting procedure in existence within AV) may be a factor within this study, and hence the data may not represent all injuries occurring during the study period. The small sample size also inhibited the ability to identify statistical significance in correlation analysis between test element scores and subsequent injury.

Further this study may include undetectable intra- and inter-rater reliability within the assessor element of the PEPCT testing undertaken by each paramedic, introducing unquantifiable skewing of the data reported.

6 Conclusion

This study has identified that musculoskeletal injury amongst Victorian paramedics is more prevalent where the paramedic is female, and/or within three years of commencement of service. The PEPCT utilized by AV did not appear able to differentiate those at risk of subsequent injury. As such, reevaluation of the pre-employment physical capacity testing process may be warranted. Further research is needed to identify workplace factors that contribute to paramedic injury.