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Occupational Medicine 2008 58(8):527-533; doi:10.1093/occmed/kqn140
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© The Author 2008. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Factors predicting dropout in student nursing assistants

Annemarie Lyng Svensson1, Jesper Strøyer2, Niels Erik Ebbehøj1 and Ole Steen Mortensen1

1 Clinic of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen NV, Denmark
2 The National Research Centre for the Working Environment, Lersø Park Allé 105, DK-2100 Kbh Ø, Denmark

Correspondence to: A. L. Svensson, Clinic of Occupational and Environmental Medicine, Bispebjerg University Hospital, DK-2400 Copenhagen NV, Denmark. e-mail: ah46{at}region.bbh.hosp.dk


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Funding
 Conflicts of interest
 References
 
Background The dropout rate among student nursing assistants (NAs) in Danish health and social care education is high at >20%.

Aims To explore if recent low back pain (LBP) history is a predictor of dropout among NA students, taking into account conventional risk factors for LBP, general health and physical fitness.

Methods Prospective study with 14-month follow-up (the duration of the education) in two schools of health and social care in the Region of Copenhagen, Denmark. Participants completed a comprehensive questionnaire, and their physical fitness (balance, back extension endurance, back flexion endurance and sagittal flexibility) was assessed at baseline. Dropout was defined as failure to complete NA education.

Results A total of 790 subjects, 87% of those invited, completed the questionnaire; 612 subjects also completed the physical tests and were included in the present study and 500 (83%) were women. Recent LBP was not an independent predictor of school dropout. However, only among women who had LBP were other factors (a history of previous exposure to heavy physical workload, a low mental health score and failure to pass the back extension endurance test) associated with risk of dropout, OR (95% CI) = 2.5 (1.2–5.3). Among men, only low height was significantly associated with dropout risk.

Conclusions A recent LBP history was not an independent single predictor of dropout from NA education but was a risk factor in combination with other factors.

Keywords      Low back pain; nursing assistants; physical fitness


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 Funding
 Conflicts of interest
 References
 
The dropout rate among student nursing assistants (NAs) in Danish health and social care education (HSCE) is high and has increased from 14% in 1993 to 24% in 2003 [1]. A corresponding dropout rate, 15–20%, has been reported among student nurses in the UK [2]. Danish reports have mainly focused on reasons for dropout related to the organization of the education itself and not on the individual factors related to health, lifestyle and physical fitness [1].

NA students and student nurses are frequently exposed to a high physical workload encompassing frequent bending or twisting of the trunk and heavy lifting, all established risk factors for low back pain (LBP) [3,4]. Thus, in a 7.5-year follow-up study of students entering nursing school, the incidence of LBP increased sharply during and after nursing school attendance [5].

Physical strength and endurance (physical fitness) are associated with a lower risk of LBP [6–8], while a high body mass index (BMI), and particularly obesity, has been implicated as a risk factor for LBP [9].

Psychosocial factors, especially those related to distress or a depressed mood, have been implicated in the transition from acute to chronic LBP [10]. In adults, patterns of the relationship between ethnicity and pain have begun to emerge. In a study from the UK, subjects of South Asian origin, when compared to non-South Asian subjects, had an increased risk of reporting disabling LBP [11].

Whether LBP or its covariates are independent risk factors for dropout in NA students is unknown. The aim of the present study was to identify dropout risk factors among students including recent LBP history and potential risk factors for LBP to test the hypothesis that recent LBP is a predictor of dropout among NA students. In addition, we analysed whether risk factors for dropout depend on gender and whether NA students have a higher LBP prevalence than the general population.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Funding
 Conflicts of interest
 References
 
The study design was that of a prospective study with 14 months of follow-up (the duration of NA education). The study was conducted in 2004–05. All participants gave written informed consent. Ethical approval was granted by Copenhagen Research Ethics Committee.

All participants completed a questionnaire and participated in a performance-based test session in the first week of NA education. The questionnaire was based on one developed by The National Research Centre for the Work Environment, Denmark [12].

Questions concerning LBP were taken from the Standardized Nordic Musculoskeletal Questionnaire [13,14]. LBP was defined as tiredness, discomfort or pain in the low back region with or without symptoms radiating to one or both legs during the previous 12 months (primary outcome) or during the subject's lifetime (secondary outcome) [15].

A self-reported history of previous exposure to heavy physical work was considered relevant if the subject reported having had a physically demanding job for at least 6 months. Occupations considered physically demanding were homecare worker, orderly (hospital attendant having general, non-medical duties), removal worker, warehouse worker, metalworker, slaughterhouse worker and fisherman.

Current smoking and leisure-time physical activity (LTPA) [16] were included as lifestyle factors. The participants classified themselves as belonging to one of four categories of LTPA, from definitely sedentary to very active, i.e. performing vigorous activity for at least 4 h/week. We included variables on age, gender, years of completed schooling and country of birth. Years of completed schooling was included as a marker of social class and participants were divided into two groups, those having completed ≤9 years of schooling or >9 years. The mandatory minimum duration of education in Denmark is 9 years, with children commencing school when they are 6–7 years old.

Psychosocial concepts were assessed with Setterlind's modified nine-item sense of coherence scale (SOC) [17,18] and Bandura's scale of self-efficacy (SE) [19,20]. Evaluation of health status was based on SF-36 general health (GH) perception, vitality (VT) and mental health (MH) scales [21,22].

To assess test–retest reliability of the questionnaire, Pearson's product–moment correlation and Kendall's rank-order correlation coefficient were used in a pilot study including 12 NA students. The results showed a high test–retest reliability with Pearson's correlation coefficients ~0.80 (range 0.58–0.98) for questions answered with a 14-day interval.

In this study, we measured the following fitness markers: balance, flexibility of the spine, back extension and back flexion endurance. To do so, we conducted four different physical fitness tests during a 90-min test session. The isometric endurance of the back muscles was measured using a modified version of the Sørensen test [23]. The subjects were placed on their stomach with their navel over the edge of a padded sloping board, which was 70 cm in length and 15 cm high at the raised end. The subject's feet were pressed down to the floor by an assistant. The hip flexion was approximately 12° during the test. To pass the test, the subject should be able to fold the arms across the chest and hold the trunk in a horizontal position for 180 s. The reliability of the test has been reported as good, showing intraclass correlation coefficients (ICCs) of 0.82–0.96 [23,24].

Isometric back flexion endurance was measured using the test described by McGill [25]. The subject was positioned in a sit-up posture, with the back resting against a jig, angled at 60° from the floor. The arms were folded across the chest, and the knees and hips were flexed at 90°. The jig was pulled back 10 cm and to pass the subject is required to hold the isometric posture for 180 s.

Sagittal flexibility, defined as the distance from the fingertips to the floor, was measured by the modified finger-to-floor method [26], in which the subject flexes the spine and hips maximally, without bending the knees while standing without shoes on a 30-cm measuring box. The test reliability was reported as good, ICC = 0.93 [27].

Balance was evaluated by the one-leg standing test, testing the ability to stand on one leg with the eyes open for 60 s. The test reliability has been reported as ICC = 0.76 [28].

Body weight was measured by a certified weighing machine with a hidden display and height was measured by an electronic height measuring unit [29]. BMI was thereby calculated.

A short one-to-one screening interview was performed before the testing to identify any reasons for exclusion. Exclusion criteria were musculoskeletal pain on the test day in the regions of testing, history of severe LBP, receiving treatment for high blood pressure, fever, headache or pregnancy. Information on dropout from NA education was based on the schools' records.

All analyses were performed using the SPSS version 14.0 [30]. Basic analyses were performed on demographic and physical test variables, using the chi-squared test (likelihood ratio), Student's unpaired t-test or Mann–Whitney rank-sum test, for categorical and continuous variables, respectively. We used Kendall’s tau-b test to disclose a possible trend in the distribution of LBP within quartiles (the lowest, the two intermediaries and the highest) of the different psychosocial variables (GH, MH, VT, SOC and SE).

We computed a simple risk factor index for school dropout by summing up presence or absence of the following risk factors: previous exposure to heavy physical workload, failure to pass the back extension endurance test and a MH score in the lowest quartile. Logistic regression analysis was used in the final models using stepwise backward elimination of variables and the maximum likelihood ratio method, accepting a priori variables with P-values <0.10 as obtained in the univariate analyses. Exit criterion for the variables in the logistic regression analysis was a P-value >0.1. Odds ratios are presented with 95% confidence limits.


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Funding
 Conflicts of interest
 References
 
Of 906 students invited, 790 participated in the study, 413 from the HSCE in the Copenhagen municipality and 377 from the HSCE in the Copenhagen County giving a final questionnaire response rate of 87%. In all, 612 students completed all physical tests and were included in the study. Those who did not complete the questionnaire were on an average younger than those who did, mean age 29 (SD = 9.3) versus 33 (10.6) years, and there were only small differences in the gender distribution. We observed no major differences in non-participation rates between the two HSCE schools.

Overall we found an acceptable level of missing values regarding questionnaire items of 2%, except for values for psychosocial scales which reached 7%. Among subjects born in foreign countries, the proportion of missing values was up to 15% for the psychosocial scales.

Seventy-one percent of subjects were born in Denmark: of the remainder, their origins were European Union, USA, Norway and Iceland (4%)—former Yugoslavia and Eastern Europe (4%), Middle East (6%), Africa (6%), Asia (5%) and others (4%).

Table 1 shows characteristics of subjects with and without 1-year prevalence of LBP according to exposure history, lifestyle and socio-demographic factors. The mean age of the study population was 33 (SD = 10) years and 500 (83%) were women. We found a 12-month prevalence of LBP of 38%. Subjects with LBP were on an average taller compared to those without, 168 (SD = 8) cm versus 166 (8) cm, P < 0.01, and more often had Danish Nationality, 83 versus 65%, P < 0.01. Among subjects with LBP during the past year, 42 versus 33%, P < 0.05, had previously been exposed to heavy physical work. We found no differences in physical activity, smoking, age, gender, education, body weight or BMI between those with and those without LBP. We found similar results for the 12-month prevalence of LBP during the last year in a gender-stratified analysis (results not shown).


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  		Table 1. Lifestyle, exposure history and other parameters in relation to 1-year prevalence of LBP among NA students

 
As seen in Table 2, subjects with LBP during the past year had significantly lower SF 36 mean scores; perception of GH, 78 versus 82, P < 0.01; VT 67 versus 73, P < 0.01 and MH, 77 versus 81, P < 0.01. Among subjects with LBP, there were significantly more subjects in the lowest quartile, (VT) 35 versus 21% and (MH) 35 versus 22%, P < 0.001. When the analysis was stratified for gender, a similar pattern was found for women, while there were no significant differences between subjects with and without LBP among men (results not shown).


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  		Table 2. Psychosocial factors in relation to the 1-year prevalence of LBP

 
As seen in Table 3, subjects with LBP had a lower flexibility of their spines compared to those without LBP, –0.7 (10) cm versus –3.0 (9) cm, P < 0.01. They also had a lower proportion passing the isometric back extension endurance test, 50 versus 59%, P < 0.05, and a lower proportion who passed the isometric back flexion endurance test, 40 versus 49%, P < 0.05. We found similar results for women only (results not shown).


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  		Table 3. Results of physical fitness tests in relation to the 1-year prevalence of LBP among NA students

 
The overall dropout rate from NA education was 29%. Overall, however, there was no difference in the 1-year prevalence of LBP between NA students who dropped out the HSCE and those who completed the programme.

The following results applied only to women, who as mentioned constituted 83% of the study population. Women who dropped out more often had a history of heavy physical workload, 44 versus 33%, P < 0.05. They also had a lower proportion passing the back extension endurance test, 47 versus 60%, P < 0.01, and a lower proportion passing the balance test, 79 versus 87%, P < 0.05. Women who dropped out had a lower mean score of MH, 76 (16) versus 81 (13), P < 0.001. Table 4 shows which covariates were significantly associated with dropout, controlling in the analysis for the three confounders identified in Table 1: age, height and years of schooling. A recent LBP history was not an independent single predictor of dropout. We found an increased risk of dropout among women with previous exposure to heavy physical workload, OR (95% CI) = 1.6 (1.1–2.4). The association between dropout and passing the back extension endurance test was OR (95% CI) = 0.6 (0.4–0.98). A MH score >72 was found to be associated with a lower risk of school dropout, OR (95% CI) = 0.52 (0.31–0.93), P < 0.05. Factors excluded from the model were one-year prevalence of LBP, age, height, <9 years of completed schooling, flexibility below floor level, SE and VT. When we excluded LBP from the model, we found an association of heavy physical workload and dropout, OR (95% CI) = 1.6 (1.0–2.5), and a MH score >72, OR (95% CI) = 0.4 (0.3–0.7).


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  		Table 4. Covariates significantly associated with dropout among NA students after adjustment in a logistic regression model

 
Among men, those who dropped out had a lower height, 175.4 (SD = 7.3) cm versus 178.8 (7.0) cm, P < 0.05. No other risk factors for dropout among men could be identified.

We estimated the population-attributable risk (PAR) of a low MH score. Assuming that all participants had a MH score above the lowest quartile, theoretically, as a point estimate 20% of the dropouts would not have occurred. Corresponding estimates of PAR for heavy physical workload and insufficient back extension endurance were 16 and 22%, respectively.

Female NA students with LBP had an increasing risk of discontinuing their studies when an increasing number of the other risk factors were present. When two or more of the above mentioned risk factors were present, recent LBP was significantly associated with dropout, OR (95% CI) = 2.5 (1.2–5.3).

With no non-LBP risk factors present, the dropout rate was 19% while with either one of the non-LBP risk factor present, it was 25%. With two or three risk factors present, the dropout risk was 39%. We included the 1-year prevalence of LBP and the risk factor index according to dropout in a logistic regression model and found a significant interaction OR (95% CI) = 1.32 (1.02–1.72).


   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Funding
 Conflicts of interest
 References
 
A recent LBP history was not an independent risk factor for study dropout among female NA students. However, among female NA students with a recent history of LBP, other factors were predictive of study dropout, namely a previous history of heavy physical workload, failure to pass a back extension endurance test and a low MH score.

The association between heavy physical workload and LBP is well-established in the literature [3,4]. A lower proportion of female NA students with LBP passed the back extension endurance test. This is in accordance with other studies where low back extension endurance, measured by the Sørensen method, is associated with an increased risk of LBP [8,28]. However, Hamberg-van Reenen et al. [31] found no association with low back extension endurance and LBP. In relation to MH, women with LBP had lower SF-36 scores.

To our knowledge, no previous studies on NA students have addressed the dropout issue, taking individual health-related factors into account. Previous studies have focused on exit interviews with some methodological problems such as recall bias. Respondents may post-rationalize and thus tend to attach more weight to study factors than individual factors. No previous studies have compared characteristics of students who drop out and those who do not using a prospective design [3].

NA students did not have a higher 12-month prevalence of LBP, when commencing their studies, compared to the same age range in the general Danish population, with a 12-month prevalence of 36% [15].

The strength of our study was that dropout was analysed in a prospective study design. We also had a large study population with a response rate of 77%. Furthermore, physical test measures and GH status were assessed in an appropriate way.

However, there are some limitations in this study. We did not have access to information about the NA students own leaving reasons. Non-responders were on an average younger compared to responders, but we found no associations between age and LBP in this study, and therefore this difference between the groups is unlikely to explain our results.

Although the prevalence of LBP in some studies increases with age [32], the dose–response relationship between age and LBP is not linear, suggesting that multiple factors are involved [11]. We had no information about household income among the NA students, and therefore used their education level as a proxy for socio-economic status.

Physical workload was based on self-reports of type of occupation and its duration. This question was unfortunately not validated in terms of different physical workload levels since the question used did not measure this.

Measurement errors or imprecision maybe relevant for both exposure and effect variables. In this study, it is unlikely that recall bias may have influenced the reporting of the 1-year prevalence of LBP since the time interval is relatively short.

With the aim of minimizing potential bias in the collection of physical test data, we used five experienced test leaders. The test leaders had no information on the subjects regarding current smoking, LTPA level and history of heavy physical work before the testing. Subjects were kept unaware of the specific hypothesis under investigation.

To ascertain that the associations between exposure and effect were not simply the result of occupational and coping-related factors, being proxies for some underlying risk factors, major potentially confounding factors known from the literature were included in the models.

Our study indicates that some individual factors may influence NA students' dropout rate, suggesting that intervention measures should be targeted at high-risk groups. For further investigation, it would be reasonable to focus on physical training, working technique and stress handling when considering an integrated intervention programme since single interventions hitherto have shown limited evidence of an effect [33].

We therefore conclude that recent LBP history is not an independent risk factor for study dropout among female NA students. However, only among female NA students with a recent history of LBP were other factors predictive of study dropout, specifically a previous history of heavy physical work, poor performance in a back extension endurance test and a low MH score.


   Funding
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Funding
Conflicts of interest
 References
 
The Working Environment Research Fund (The Danish Employment Ministry).


Key points
  • Recent LBP was not an independent risk factor for dropout from the health and social care school.
  • In female NA students with a recent history of LBP, other factors (a previous history of heavy physical work, poor performance in a back extension endurance test and a low MH score) were predictive of study dropout.
  • Further investigation of interventions to reduce dropout rates should focus on physical training, working technique and stress handling.

 


   Conflicts of interest
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Funding
 Conflicts of interest
References
 
None declared.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Funding
 Conflicts of interest
 References
 

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