Musculoskeletal disorders,psychosocial stress and associated factors among home-based migrant care workers

Abstract

BACKGROUND:

Prevalence of musculoskeletal disorders (MSDs) and psychological stress in home-based female migrant care workers (MCWs) remain unknown.

OBJECTIVE:

To 1) investigate the prevalence of MSDs and psychological stress and associations between subjective questionnaires on MSDs/psychological stress and biomedical examinations, and 2) identify the risk factors related to MSDs and psychological stress.

METHODS:

This study recruited 85 MCWs. Data was collected using questionnaires, urine analysis and X-ray examinations. Correlations between subjective questionnaires and biomedical examinations were investigated. Multivariable logistic regression analyses were used to explore risk factors.

RESULTS:

The prevalence of MSDs and psychological stress were 70.6% and 37.6%, respectively. MSDs were commonly reported over the neck, lower back, shoulders, and upper back. There was a moderate correlation between MSDs and abnormal X-ray findings. Risk factors associated with MSDs included higher education level, frequent transferring and bedside care activities, lacking caregiver training in Taiwan, inadequate sleep, and drinking tea or coffee. Risk factors associated with psychological stress included inadequate salary, lacking caregiver training in Taiwan, and insufficient knowledge of body mechanics techniques.

CONCLUSIONS:

MSDs and psychological stress were common among home-based female MCWs. Educational level, frequent transferring and bedside care activities, and lack of caregiver training in Taiwan, were the most dominant risk factors.

Keywords

1 Introduction

Health care workers (HCWs) often suffer from work-related musculoskeletal disorders (MSDs) as well as psychological stress. MSDs refer to a wide range of inflammatory and degenerative conditions devastating the muscles, tendons, ligaments, joints, intervertebral discs, cartilages, bones, peripheral nerves, and supporting blood vessels [1, 2]. Psychological stress refers to the emotional and physiological responses perceived in the situation in which imbalance exists between high demands and inadequate resources to cope with these demands [3, 4]. Current research on MSDs and psychological stress primarily focuses on professional HCWs [5 –8]. No previous studies on MSDs have focused exclusively on non-professional care providers, such as home-based female migrant care workers (MCWs). Female MCWs from developing countries are emerging as important personal care providers and employees at home settings in aging societies to meet the societal needs caused by the potential insufficiency of domestic non-professional HCWs and family members [9, 10]. This study investigated the MSDs and psychological stress in home-based female MCWs.

Previous investigations have reported that MSDs and psychological stress are both common in HCWs [4 , 11–16]. The prevalence of MSDs is 38–60%, 47–72%, and 26–71% over the neck, shoulders, and lower back, respectively [11 –15]. The prevalence of psychological stress is 22–75% in HCWs [4, 16]. MCWs may be low-skilled and lack professional training, endure heavy physical demands, and experience high job demands without adequate resources to cope with these demands [4, 17]. This study was conducted to examine information on the prevalence of MSDs in home-based female MCWs, which currently remains unknown.

Previous studies investigating the MSDs and psychological stress in HCWs used self-reported measures. Whether the self-reported MSDs reflect the physical problems assessed by objective measurements remains unclear. This information could serve as the foundation for a prevention strategy. In this study, we therefore used X-ray imaging and concentrations of 17-hydroxycorticosteroids (17-OHCS) as our objective measurements for MSDs and psychological stress, respectively. X-ray imaging is a common radiologic procedure for diagnosing MSDs [18], especially for MSDs related to injuries of joints, intervertebral discs, and bones. 17-OHCS is an inactive metabolite of the steroid stress hormone (i.e. cortisol) that can reflect the increased rate of cortisol synthesis. The daily excretions of 17-OHCS corrected by creatinine can be used as a stress barometer for assessing psychological stress [19].

Information on risk factors associated with MSDs and psychological stress among female MCWs is important for preventive interventions to reduce MSDs and psychological stress because these may affect the social and economic burden and individual quality of life, accounting for short-term or temporary work disability and hospital costs [20, 21]. The risk factors associated with MSDs and/or psychological stress in HCWs include (1) personal factors, such as demographic (female, older age) and lifestyle (exercise habits and drinking tea or coffee) [22 –27]. For example, consumption of caffeinated drinks (e.g. coffee and tea) has been suggested to be a potential factor contributing to MSDs. Excessive consumption of caffeinated drinks may cause imbalance of calcium and result in impaired bone health [26, 27]; 2) physical factors, such as repetitive lifting, patient handling and transferring, persistent awkward posturing, and having insufficient knowledge of body mechanics/transfer techniques [23 , 29]; 3) psychosocial factor, such as financial constraints [17, 25]; and 4) organizational/work factors, such as less time off work or short breaks and poor working environment [22, 30]. Physical fitness is also related to MSDs in the general and working population [10 , 32] and may be related to psychological stress. However, whether physical fitness is associated with the occurrence of MSDs and psychological stress in MCWs remains unclear. This study was conducted to identify the risk factors predicting MSDs and psychological stress among home-based female MCWs.

In summary, no studies have focused exclusively on home-based female MCWs. The objective evidence on MSDs and psychological stress is still lacking. Considering the effects of MSDs and psychological stress on individual and social costs, determining risk factors related to MSDs and psychological stress is critical for prevention. The aims of this study were to (1) investigate the prevalence of MSDs and psychological stress among home-based female MCWs and associations between subjective surveys about MSDs/psychological and findings in biomedical examinations, and (2) identify the associated risk factors related to MSDs and psychological stress.

2 Materials and methods

2.1 Sample size estimation

Based on the guidelines established in Lipsey & Wilson (2001) [33], a logistic regression was conducted using G*Power software [34] to determine the sample size. With a large effect size (odd ratio = 2.48), a power of 0.80, and a two-sided type I error of 0.05, the sample size calculation resulted in, at least, 71 participants.

2.2 Study subjects and design

This was a cross-sectional study conducted at the Chang Gung Memorial Hospital, Kaohsiung, Taiwan. The convenience sampling comprised 85 home-based female MCWs working for patients. Participants younger than 60 years old and able to speak Chinese or Taiwanese were recruited. This study protocol was approved by the Chang Gung Medical Foundation Institutional Review Board, and all participants signed the written informed consent form.

Participants completed questionnaires that consisted of four parts: personal traits and associated risk factors, knowledge of patient handling and transfer techniques, musculoskeletal symptoms, and psychological stress. The contents of these questionnaires were provided in details in the paragraphs below (i.e. 2.3. Instruments). They received objective biomedical examinations to verify the relationship between the objective measures with self-reported MSDs and psychological stress. Physical fitness was also assessed to obtain additional information.

2.3 Instruments

2.3.1 Personal trait and associated risk factors questionnaire

To characterize participant traits and associated risk factors, the questionnaire, which included items on personal, physical, psychosocial, and organizational/work characteristics, was developed for this study, with empirical support from previous studies reviewed on this topic. Personal characteristics included age, height, weight, body mass index, educational level, marital status, number of children, exercise habits, and drinking tea or coffee. Physical characteristics addressed frequency of transferring and bedside care activities. Psychosocial characteristics included the perception of fair salary and sufficient sleep. Organizational/work characteristics included working experiences, previous training on caregiving, working day, working hour, helper, and additional housework.

2.3.2 Transfer Skill Test questionnaire

One of the physical factors, the knowledge of patient handling and transfer techniques, was assessed by Transfer Skill Test with 10 yes-no questions consisting of words and pictures describing body mechanics principles for caregivers to handle and transfer patients, for example transfer patients from wheelchair to the bed and from sit to stand, roll patient or clap patients on their backs in the bed [35]. The subject received 1 point for “yes” and 0 points for “no” in each question (score range: 0–10). A score of less than 6 was defined as the insufficient knowledge of body mechanics techniques.

2.3.3 Physical fitness tests

Physical fitness, including grip strength, trunk flexibility, and abdominal/back muscular endurance, was assessed in accordance with testing methods developed by the Taiwan Institute for Occupational Safety and Health. These physical fitness tests are standardized and norm-referenced tests recognized by the Taiwan Institute for Occupational Safety and Health in Taiwan. Grip strength was evaluated by hand grips to measures the maximum isometric strength of the dominant hand and forearm muscles. Trunk flexibility was assessed by how far the trunk could bend forward in the standing position when subjects stood with their feet hip distance apart and bended their trunks as far forward as they could without bending their knees [36]. The best performance during three trials was recorded. Abdominal/back muscular endurance was measured by the total numbers of repetitive abdominal curls while supine and trunk extension while prone performed in one minute [36]. All outcome data was first classified into a five-point scale (i.e. much worse, worse, comparable, better, or much better than those of the same age) based on the normative data adjusted for age and genders and constructed by Taiwan Institute for Occupational Safety and Health (https://www.ilosh.gov.tw/menu/1188/1201/1203/1846/). Then, these data was converted into two fitness categories, poor (including much worse and worse) and fair-good (including comparable, better, and much better) for data analysis [36, 37].

2.3.4 Nordic Musculoskeletal Questionnaire (NMQ)

NMQ, using an anatomical figure, was used to measure MSDs [38]. Questions related to the occurrence of pain or discomfort of the human body over nine anatomical areas (neck, shoulders, elbows, wrists/hands, upper back, lower back, hips/thighs, knees, and ankles/feet) within the past year. In case of a positive answer, we asked whether the discomfort affected the subject’s work and daily living.

2.3.5 Caregiver Strain Index (CSI)

The CSI is a 13-question self-administered questionnaire for screening the MCW’s stress in five domains of caregiving: employment, financial, physical, social, and time [37]. The subject received 1 point for “yes” and 0 points for “no” in each question (score range: 0–13). Higher scores indicate a higher the level of psychological stress, with a score of 7 or higher indicated a great level of stress [4, 39].

2.3.6 Biomedical examinations

X-ray imaging and urine analysis were performed to examine the relationship between objective biomarkers and the subjective self-reported NMQ/CSI surveys. X ray was used specifically to examine injuries/abnormalities of joints, intervertebral discs and bones (e.g. irregularity, spur formation of the bones, narrowing of space and changes in intervertebral discs) to determine neuromuscular and degenerative conditions. Subjects underwent cervical and lumbar X-ray imaging, and the images were accessed by board certificated radiologists who were not involved in the study at the study hospital. One study investigator (KCC) who was blind to the clinical information collected the assessments and categorized the data by regions and abnormality. Levels of stress were assessed by analyzing 17-OHCS and creatinine in a 24-hour urine collection. A special container was given to participants. They were instructed on how to collect their urine sample properly into this container for a continuous 24-hour period. On day 1, participants discarded their first morning sample, and started to collect their urine into the special container for the following 24 hours. Participants were also instructed to keep the urine sample in the refrigerator or a cool place during the collection period. They returned the urine sample to researchers at the hospital after completing 24-hour urine collection. Normal limit of 17-OHCS in women is 2 to 7 mg/day. Urinary creatinine is commonly used as a gross index to the completeness of 24 h urine collections and as a basis of expression for the excretion of other compounds. The 24-hour urinary 17-OHCS concentration was expressed as mg/g of urinary creatinine.

2.4 Statistical analysis

Statistical analyses were performed with SPSS 18.0 software (SPSS Inc., Chicago, IL). Descriptive statistics were used to describe the general characteristics of participants. Data collected from NMQ and CSI was analyzed for the prevalence of MSDs and psychological stress, respectively. The relationship between the cervical and lumbar spine X-ray examination and the NMQ was determined by the phi (φ) coefficient. The relationship between 17-OHCS/creatinine and CSI was assessed by Pearson’s correlation. Logistic regression analyses were used to identify potential risk factors of MSDs at each body region and psychological stress. The potential risk factors with a significance level of P≤0.2, identified by the univariate logistic regression analyses, were entered into the multivariable logistic regression models (stepwise method: forward conditional). Odds ratios (ORs) of risk factors were generated from the analyses, and a P value of <0.05 was considered to be statistically significant.

3 Results

3.1 Participant description

The MCWs were a mean age of 31.4±6.4 years, and 67% were married. The educational level of 45 MCWs (52.9%) was senior high school or higher. MCWs had an average of 1.4±2.2 years of working experience. About 66% of MCWs completed caregiver training courses in their home countries. The caregiver training courses contain at least 90 hours of lectures, clinical practice of nursing and caregiver skills, and emergency management skills. After completion of training courses, MCWs will be qualified to work as caregivers in Taiwan. About 20% of MCWs completed caregiver training courses in Taiwan that consists of 50–60 hours of lectures (including basic nursing, communication and emergency management skills, mental health and stress adaptation, the use of proper body mechanics techniques, use of assistive devices, and etc.) and 40 hours of clinical practice. They will be qualified for applying for national caregiver certification exams after completion of training courses. The averaged working days were 29.8±1.0 days per month. 81.1% of MCWs worked more than 16 hours daily, 72.9% of them performed additional housework, and 25.9% of them had helpers to support their routine work. 57% and 59% MCWs had self-perceived adequate salary and sleep, respectively. The mean score of Transfer Skill Test was 6.6±1.9 points. 69.4% of MCWs scored greater than 6 on the Transfer Skill Test. For the physical fitness tests, most MCWs had fair-good grip force (76.4%) and flexibility (94.1%) but poor abdominal muscular endurance (58.8%) and back muscular endurance (63.5%) (Table 1).

Table 1
Characteristics (personal, physical, psychosocial, organizational, and physical fitness factors) of the MCWs

Mean±SD or N (%)

Personal Factors

Age (yrs) 31.4±6.4

Body height (cm) 156.2±4.9

Body weight, (Kg) 54.1±7.0

BMI (Kg/m²) 22.2±2.6

Overweight and obese (≥24 Kg/m²) 20 (23.5)

Educational level

Senior high school or above 45 (52.9)

Married 64 (75.3)

Having children 63 (74.1)

No. of children 1.2±1.0

Exercise habits 17 (20.0)

Drinking tea or coffee 58 (68.2)

Physical Factors

Bed-side care activities (times/day) 12.5±8.9

≥12.5 times/day 35 (41.2)

Transferring activities (times/day) 7.4±6.9

≥7.4 times/day 33 (38.8)

Knowledge of body mechanics techniques (points) 6.6±1.9

≥6 points 59 (69.4)

Psychosocial Factors

Adequate salary 57 (67.1)

Adequate sleep 59 (69.4)

Organizational/Work Factors

Working experience (yrs) 1.4±2.2

Caregiver training in MCWs’ home countries 56 (65.9)

Caregiver training in Taiwan 17 (20.0)

Working days per month 29.8±1.0

Working hours≥16 hours/day 69 (81.2)

Helper 22 (25.9)

Additional housework 62 (72.9)

Physical Fitness Factors

Grip force (Kg) 28.9±4.8

Poor 20 (23.5)

Fair –Good 65 (76.4)

Flexibility (cm) 16.2±9.3

Poor 5 (5.9)

Fair –Good 80 (94.1)

Abdominal muscular endurance (times/min) 8.9±10.1

Poor 50 (58.8)

Fair –Good 35 (41.2)

Back muscular endurance (times/min) 39.1±16.5

Poor 54 (63.5)

Fair –Good 31 (36.5)

	Mean±SD or N (%)
Personal Factors
Age (yrs)	31.4±6.4
Body height (cm)	156.2±4.9
Body weight, (Kg)	54.1±7.0
BMI (Kg/m²)	22.2±2.6
Overweight and obese (≥24 Kg/m²)	20 (23.5)
Educational level
Senior high school or above	45 (52.9)
Married	64 (75.3)
Having children	63 (74.1)
No. of children	1.2±1.0
Exercise habits	17 (20.0)
Drinking tea or coffee	58 (68.2)
Physical Factors
Bed-side care activities (times/day)	12.5±8.9
≥12.5 times/day	35 (41.2)
Transferring activities (times/day)	7.4±6.9
≥7.4 times/day	33 (38.8)
Knowledge of body mechanics techniques (points)	6.6±1.9
≥6 points	59 (69.4)
Psychosocial Factors
Adequate salary	57 (67.1)
Adequate sleep	59 (69.4)
Organizational/Work Factors
Working experience (yrs)	1.4±2.2
Caregiver training in MCWs’ home countries	56 (65.9)
Caregiver training in Taiwan	17 (20.0)
Working days per month	29.8±1.0
Working hours≥16 hours/day	69 (81.2)
Helper	22 (25.9)
Additional housework	62 (72.9)
Physical Fitness Factors
Grip force (Kg)	28.9±4.8
Poor	20 (23.5)
Fair –Good	65 (76.4)
Flexibility (cm)	16.2±9.3
Poor	5 (5.9)
Fair –Good	80 (94.1)
Abdominal muscular endurance (times/min)	8.9±10.1
Poor	50 (58.8)
Fair –Good	35 (41.2)
Back muscular endurance (times/min)	39.1±16.5
Poor	54 (63.5)
Fair –Good	31 (36.5)

MCWs, Migrant care workers; BMI, body mass index; SD, standard deviation. Values are presented as mean±SD or N (%). N (%) indicates the number (percentage) of subject.

3.2 Prevalence of MSDs and psychological stress

During the preceding year, 70.6% MCWs reported MSDs over at least one body site. The most commonly discomfort sites were neck (40.0%), lower back (37.6%), shoulders (35.3%), and upper back (32.9%) (Fig. 1A). Of the MCWs with MSDs over any body area, 49.4% reported that MSDs had an effect on work and daily living and that the primary sites of MSDs devastating work and daily living included the neck (70.6%), shoulders (66.7%), wrists/hands (73.3%), and knees (70%) (Fig. 1B).

Fig.1

Prevalence rates in home-based female MCWs. (A) Prevalence of musculoskeletal disorders (MSDs) during the past year. (B) Prevalence of MSDs which negatively affected work and daily living during the past year.

The averaged CSI scores for MCWs were 6.0±2.1, with 37.6% scoring 7 or more points, indicating a high level of psychological stress. The chief stress item was long working time (94.1%), and the second was the disturbed sleep (85.9%) (Table 2).

Table 2

The level of MCWs’ psychological stress screened by Caregiver Strain Index (CSI)

Caregiver Strain Index (CSI)	N (%)
1. Sleep is disturbed	73 (85.9)
2. It is inconvenient	38 (44.7)
3. It is a physical strain	43 (50.6)
4. It is confining	56 (65.9)
5. There have been family adjustments	37 (43.5)
6. There have been changes in personal plans	56 (65.9)
7. There have been other demands on my time	13 (15.3)
8. There have been emotional adjustments	17 (20.0)
9. Some behavior is upsetting	35 (41.2)
10. It is upsetting to find his/her condition has changed so much from his/her former self	13 (15.3)
11. Long working time	80 (94.1)
12. It is a financial strain	31 (36.5)
13. Feeling completely overwhelmed	15 (17.6)
Total Score (0–13)	6.0±2.1
Considerable Caregiver Strain (CSI ≥ 7 points), n (%)	32 (37.6)

N (%) indicates the number (percentage) of subject who responded “Yes” to this question. Values are presented as mean±SD or N (%).

3.3 Association between subjective surveys and biomedical examinations

X-ray imaging was available for 39 of the 89 MCWs. The percentage of abnormal findings detected by the X- ray examination was 35.9% over the cervical region and 47.2% over the lumber region. Significant correlations were not found (all p > 0.23) except for a positive moderate correlation shown between lumbar spine X-ray abnormality and MSDs over any area (φ = 0.39, p = 0.01).

Urine analysis results were available for 47 of the 89 MCWs. The 24 h urinary 17-OHCS value was 9.1±5.0 mg, and 59.6% of MCWs had a value of more than 7 mg. The 17-OHCS/creatinine ratio was 8.9±5.9 mg/g. However, the urinary 17-OHCS or 17-OHCS/creatinine ratio was not significantly correlated to psychological stress (CSI scores) (p = 0.46).

3.4 Risk factors for MSDs

Potential risk factors for MSDs, including personal, physical, psychosocial, organizational/work, and physical fitness factors, are presented in Table 1. Table 3 reports the results in the univariate logistic regression analysis for the potential predictors that were associated with MSDs in discomfort body regions of any area, neck, shoulders, upper back, or lower back/waist. Factors such as educational level, drinking tea or coffee, frequency of transferring and bedside care activity, salary, sleep, working time, knowledge of body mechanics techniques, and physical fitness determined in the univariate analyses were entered into the multivariable models. Table 4 presents the main factors associated with MSDs in the multivariable model. Significant risk factors associated with MSDs over any area were drinking tea or coffee (OR = 3.21, p = 0.048) and more frequent transferring activities (OR = 3.54, p = 0.04). Neck pain was associated with higher educational level (OR = 3.48, p = 0.01). Lack of caregiver training in Taiwan (OR = 5.18, p = 0.03), more frequent transferring activities (OR = 4.31, p < 0.01), and inadequate sleep (OR = 3.03, p = 0.04) were related to shoulder pain. Upper back pain was associated with higher education level (OR = 3.41, p = 0.02). Higher education level (OR = 4.84, p < 0.01) and more frequent bedside care activities (OR = 2.85, p = 0.04) were associated with lower back/waist pain (Table 4).

Table 3
Results from univariate logistic regression analyses for risk factors associated with MSDs and psychological stress in MCWs

Risk factors Any area Neck Shoulders Upper back Lower back/Waists Psychological stress (CSI) ≥ 7

OR P-value OR P-value OR P-value OR P-value OR P-value OR P-value

Personal Factors

Educational level (Senior high school or above) 3.42^* 0.02 3.43^* 0.01 – – 3.20^* 0.02 4.57^† <0.01 3.60^* 0.01

Drinking tea or coffee 2.77^* 0.04 – – – – 2.14 0.16 2.17 0.13 – –

Physical Factors

Frequent bed-side care activities (≥12.5 times/day) 2.32 0.10 1.95 0.14 – – – – 2.65^* 0.04 – –

Frequent transferring activities (≥7.4 times/day) 2.67 0.07 – – 3.11^* 0.02 – – – – – –

Insufficient knowledge of body mechanics techniques (<6 points) – – – – – – – – 2.11 0.12 2.11 0.12

Psychosocial Factors

Inadequate salary – – 1.85 0.19 – – – – – – 5.53^† <0.01

Inadequate sleep – – – – 2.47 0.06 – – 2.11 0.12 – –

Organizational/Work Factors

Previous working experience 0.49 0.15 – – – – – – – – – –

Lack of caregiver training in MCWs’ home countries – – – – 1.86 0.19 – – – – – –

Lack of caregiver training in Taiwan – – – – 3.07 0.10 – – – – 3.47 0.07

Work ≥16 hours/day – – – – 2.79 0.14 – – – – – –

Helper 0.49 0.17 0.35 0.06 – – – – – – – –

Additional housework – – – – – – – – – – 2.05 0.19

Physical Fitness Factors

Poor grip force – – – – – – 2.61 0.07 1.96 0.20 2.56 0.07

Poor flexibility – – – – – – – – – – 7.43 0.08

Poor back muscle endurance – – – – – – 2.18 0.13 – – – –

Risk factors	Any area	Neck	Shoulders	Upper back	Lower back/Waists	Psychological stress (CSI) ≥ 7
Personal Factors
Educational level (Senior high school or above)	3.42^*	0.02	3.43^*	0.01	–	–	3.20^*	0.02	4.57^†	<0.01	3.60^*	0.01
Drinking tea or coffee	2.77^*	0.04	–	–	–	–	2.14	0.16	2.17	0.13	–	–
Physical Factors
Frequent bed-side care activities (≥12.5 times/day)	2.32	0.10	1.95	0.14	–	–	–	–	2.65^*	0.04	–	–
Frequent transferring activities (≥7.4 times/day)	2.67	0.07	–	–	3.11^*	0.02	–	–	–	–	–	–
Insufficient knowledge of body mechanics techniques (<6 points)	–	–	–	–	–	–	–	–	2.11	0.12	2.11	0.12
Psychosocial Factors
Inadequate salary	–	–	1.85	0.19	–	–	–	–	–	–	5.53^†	<0.01
Inadequate sleep	–	–	–	–	2.47	0.06	–	–	2.11	0.12	–	–
Organizational/Work Factors
Previous working experience	0.49	0.15	–	–	–	–	–	–	–	–	–	–
Lack of caregiver training in MCWs’ home countries	–	–	–	–	1.86	0.19	–	–	–	–	–	–
Lack of caregiver training in Taiwan	–	–	–	–	3.07	0.10	–	–	–	–	3.47	0.07
Work ≥16 hours/day	–	–	–	–	2.79	0.14	–	–	–	–	–	–
Helper	0.49	0.17	0.35	0.06	–	–	–	–	–	–	–	–
Additional housework	–	–	–	–	–	–	–	–	–	–	2.05	0.19
Physical Fitness Factors
Poor grip force	–	–	–	–	–	–	2.61	0.07	1.96	0.20	2.56	0.07
Poor flexibility	–	–	–	–	–	–	–	–	–	–	7.43	0.08
Poor back muscle endurance	–	–	–	–	–	–	2.18	0.13	–	–	–	–

Risk factors with P-value ≤0.2 were listed. –: P-value >0.2. ^*P < 0.05; ^† P < 0.01.

Table 4

Results from multivariable logistic regression analyses for risk factors associated with MSDs and psychological stress in MCWs

Risk factors	Any area		Neck		Shoulders		Upper back		Lower back/Waist		Psychological stress (CSI) ≥ 7
	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)
Personal Factors
Educational level (Senior high school or above)	2.90	0.98–8.53	3.48^*	1.31–9.23	–	–	3.41^*	1.26–9.21	4.84^†	1.72–13.58	2.79	0.89–8.70
Drinking tea or coffee	3.21^*	1.01–10.24	–	–	–	–	–	–	–	–	–	–
Physical Factors
Frequent bed-side care activities (≥12.5 times/day)	3.14	0.96–10.26	2.17	0.82–5.72	–	–	–	–	2.85^*	1.06–7.65	–	–
Frequent transferring activities (≥7.4 times/day)	3.54^*	1.06–11.81	–	–	4.31^†	1.53–12.10	–	–	–	–	–	–
Insufficient knowledge of body mechanics techniques (<6 points)	–	–	–	–	–	–	–	–	2.38	0.84–6.75	3.91^*	1.10–13.87
Psychosocial Factors
Inadequate salary	–	–	–	–	–	–	–	–	–	–	10.14^†	2.80–36.70
Inadequate sleep	–	–	–	–	3.03^*	1.06–8.72	–	–	–	–	–	–
Organizational/Work Factors
Lack of caregiver training in Taiwan	–	–	–	–	5.18^*	1.18–22.67	–	–	–	–	5.48^*	1.06–28.37
Helper	2.49	0.73–8.42	0.36	0.11–19	–	–	–	–	–	–	–	–
Additional housework	–	–	–	–	–	–	–	–	–	–	2.99	0.82–10.96
Physical Fitness Factors
Poor flexibility	–	–	–	–	–	–	–	–	–	–	7.50	0.54–97.99
Poor back muscle endurance	–	–	–	–	–	–	2.40	0.84–6.82	–	–	–	–
Nagelkerke R²	0.290		0.196		0.229		0.136		0.247		0.448

^* P < 0.05; ^† P < 0.01; –: factors not entering the designated multivariable model.

3.5 Risk factors for psychological stress

Higher education level, insufficient knowledge of body mechanics techniques, inadequate salary, lack of caregiver training in Taiwan, additional housework, poor grip force, and poor flexibility determined by the univariate logistic regression analyses (Table 3) were selected and entered into the multivariable model. Lack of caregiver training in Taiwan (OR = 3.91, p = 0.04), insufficient knowledge of body mechanics techniques (OR = 10.14, p < 0.01), and inadequate salary (OR = 5.48, p = 0.04) were significant risk factors related to higher psychological stress (Table 4).

4 Discussion

The finding of this study is novel because this study investigated the MSDs among home-based female MCWs, a neglected population that is vulnerable to MSD and psychological stress. This study has several findings. First, MSDs were common among home-based female MCWs, especially over neck, shoulders, and upper and lower back. MCWs also experienced psychological stress, with more than one-third reporting higher levels of stress assessed by the CSI. Second, risk factors associated with MSDs included higher education level, frequent transferring and bedside care activities, drinking tea or coffee, inadequate sleep, and lack of caregiver training in Taiwan. Risk factors associated with psychological stress included lack of caregiver training in Taiwan, inadequate salary, and insufficient knowledge of body mechanics.

4.1 MSDs prevalence

Not surprisingly, a vast majority of female MCWs experienced MSDs during the past year. The most prevalent body region experiencing MSDs was the neck, followed by the lower back, shoulders, and upper back. This result was consistent with the findings in previous studies among nursing personnel, except for the lower prevalence of back pain in this study [6 , 42]. Furthermore, our results of “Transfer skill test questionnaire” showed that MCWs had insufficient knowledge of transferring and handling skills. It is possible that they incorrectly used upper arms instead of the trunk to move or lift patients and resulted in development of neck and shoulder pain [43, 44]. In addition, the primary sites of MSDs affecting work and daily living reported by MCWs were the neck, shoulders, wrists/hands, and knees, but not the back. Although MSDs over wrists/hands and knees were not highly prevalent compared with other sites, primary prevention or treatment strategies for decreasing MSDs should not neglect these areas because they negatively influenced work and daily function.

4.2 Psychological stress prevalence

By using CSI, this study showed that MCWs experienced some level of psychological stress, with 37.6% of participants experiencing a high level of stress, higher than the finding of a previous study of caregivers of disabled or elderly people [16, 45], suggesting that the MCWs might experience a higher level of stress than domestic personnel. While attending to the details in the CSI, the stress could be mostly from long working hours and disturbed sleep (see Table 2) but could also be from performing additional housework (72.9%) and not having helpers (74.1%) (see Table 1). Future research might compare the differences in prevalence and types of psychological stress between domestic care workers and MCWs.

4.3 Subjective surveys and objective biomedical examinations

Although a moderate positive correlation was found between MSDs over any body area and abnormalities in X-ray imaging of the lumbar spine, no significant relationships were noted between MSDs over three specific areas—neck, shoulders, and back—and abnormalities on the X-ray image. No relationship was found between the CSI score and the corrected urinary 17-OHCS level. One possible explanation is the small sample size: only 39 MCWs (42.4%) underwent the X-ray examination and 47 (55.29%) underwent the urine analysis. The other possible explanations are that the biomedical markers (X-ray, 17-OHCS) may not be sensitive enough to observe the subtle changes in MSDs and psychological stress and that the cause of the MSDs may be soft tissue injury rather than a bony problem. The urinary 17-OHCS is produced primarily in response to acute rather than chronic stress. However, the psychological stress in MCWs may be in a chronic and prolonged condition that may not alter the levels of 17-OHCS at the time of collection [46]. Further studies could use other biomedical markers such as serum tumor necrosis factor-α, salivary cortisol to assess levels of psychological stress and soft tissue sonography to evaluate work-related soft tissue injuries in muscles, tendons or ligaments of the neck, shoulder and back [47, 48].

4.4 Factors associated with MSDs

The most dominant risk factor associated with MSDs over the neck and upper/lower back was a higher educational level. Participants with a higher educational level appeared to have a 341% –484% higher risk of MSDs over these regions than their counterparts. We speculated that these better educated MCWs might have more demanding cases or experience higher expectation from the clients than MCWs with lower educational levels because they have better skills/knowledge of taking care of their clients [49]. This result is consistent with one previous study that reported greater risks of developing shoulder pain in health professional workers (e.g. dentists) with higher educational levels. However, our results were contrary to previous studies indicating the lower educational level as a risk factor for developing MSDs in workers employed in hospitals and home care service centers [50, 51]. The possible reasons for the discrepancy between our study and previous studies could be the differences in job responsibilities and personal characteristics between home-based MCWs and hospital/home care service workers. For example, most of the MCWs in our study perform not only caregiving, but also additional house work and work long hours daily compared to workers in the previous study. Moreover, personal characteristics including sex, body weight, and severity of disability or disease were different between MCWs in our study and workers in the previous studies. These differences in job responsibilities and personal characteristics may result in different findings between ours and the previous study [52 –54]. Future studies could examine if personal characteristics in combination with the contents, duration or intensity of the job would affect the occurrence of MSDs in MCWs.

Frequent transferring and bedside care activities were the second dominant risk factors. While frequent transferring activities was related to MSDs over any area and the shoulders, frequent bedside care activities was associated with MSDs over the lower back. MCWs who combine highly demanding care work with frequent transferring of patients possibly makes them prone to work-related musculoskeletal injuries. Previous studies have shown a higher load on the lower back during patient handling tasks such as transferring and bedside care [55]. However, poor abdominal and back muscle endurance was not a risk factor of MSDs in lower back in this study. The reason could be that patient handling tasks such as bedside care activities rely primarily on the control and stability, but not the endurance of the core muscles, including the deep core muscles (e.g. transversus abdominis, lumbar multifidus, and internal oblique muscle) and the shallow core muscles (e.g. rectus abdominis, internal and external oblique muscles, erector spinae) [56]. Therefore, core stability training and core muscle control exercise as well as use of assistive devices during bedside care and transferring activities may be helpful for decreasing the occurrence of back pain or any site pain [57, 58]. Further studies are needed to investigate the effects of core stability training, core muscle control exercise and assistive devices on MSDs in MCWs.

Other risk factors included drinking tea or coffees, inadequate sleep, and lack of caregiver training in Taiwan. MCWs may drink caffeinated beverages for an energy boost to deal with the highly demanding care work. Because of the correlation between inadequate sleep and shoulder pain, we suggest employers should pay attention to the duration of sleep provided to the MCWs. In addition, we found that only 20% of MCWs received caregiver training in Taiwan and that lack of caregiver training in Taiwan is the dominant factor of shoulder pain; thus, to receive comprehensive caregiver training in Taiwan may be critical to prevent MSDs in MCWs. Further studies could verify the effects of domestic caregiver training (in Taiwan) on preventing the occurrence of MSDs.

4.5 Factors associated with psychological stress

The female MCWs with lack of caregiver training in Taiwan, inadequate salary, and insufficient knowledge of body mechanics techniques were at a higher risk of psychological stress. The lack of domestic caregiver training may expose MCWs to uncertainty and difficulties when caring for disabled or elderly people, leading to psychological stress. Offering additional caregiver training for MCWs when they come to Taiwan might be beneficial for improvement of their psychological health Moreover, the psychological stress was 10.14 times higher in MCWs with an inadequate salary than in those with an adequate salary. The finding is consistent with the result of the study on caregivers of the elderly reporting that financial impact is strongly correlated with the perceived caregiver burden [17]. The inadequate salary may be a stressor for MCWs, because unlike domestic workers, many MCWs work in a foreign country to provide increased financial assistance to their own family. Furthermore, the use of proper body mechanics techniques is critical to prevent injuries [28, 29], which may relieve psychological stress [41, 59]. This study supports the importance of understanding proper body mechanics techniques.

A few limitations to the current study should be mentioned. First, in the physical fitness domain, only certain muscle groups were measured. Further studies may be needed to explore the relationship between MSDs/psychological stress and physical fitness of other muscle groups. Second, participants were recruited only if they spoke Chinese or Taiwanese. This implies that the findings of this study might not generalize to those MCWs without proficient Chinese. Therefore, the prevalence of MSDs and increased psychological stress may be underestimated in this study. Further studies are needed to investigate the MSDs and psychological stress in all MCWs. Third, in addition to psychological stress, it is possible that the feeling of marginalization may affect physical health of MCWs [60]. Future studies could explore the association of feeling of marginalization and the occurrence of MSDs in migrant care workers.

5 Conclusions

In conclusion, MSDs and psychological stress were common among home-based female MCWs. Higher educational levels, frequent transferring and bedside care activities, and lack of domestic caregiver training (in Taiwan) were the most dominant risk factors of MSDs and psychological stress. The results can provide information to employers and government policy makers to prevent or minimize the disabling effect of factors associated with MSDs and psychological stress among this neglected ethnic group and remind them to supply adequate intervention/prevention strategies.

Authors’ contributions

KC Chang, YH Liao, HC Lee, and CY Wu conceptualized and designed the study. KC Chang, HC Lee, PL Lin, YC Huang, MC Chou, YH Li, and HM Lin contributed to the acquisition of data. HC Lee, CL Yen, PL Lin, JW Huang, YC Huang, MC Chou, YH Li, and HM Lin participated in the data interpretation. KC Chang, YH Liao, and CY Wu wrote up and finalized the manuscript. All authors have approved the final manuscript.

Conflict of interest

The authors have no conflict of interest to declare.

Ethics approval

This study was approved by the Chang Gung Medical Foundation Institutional Review Board.

Funding

The authors disclosed receipt of the following financial support for the research: Chang Gung Memorial Hospital (CMRPG890391, CMRPD1F0411-0412, BMRP553, BMRP718), Healthy Aging Research Center at Chang Gung University (EMRPD1G0241), and Ministry of Science and Technology (NSC101-2314-B-010-067, MOST105-2314-B-010-056) in Taiwan.

Patient consent

Obtained.

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