Musculoskeletal Pain in Elderly in a City in Southern Brazil: Prevalence and associated factors

Musculoskeletal pain in the elderly affects functional capacity and influences increased frailty, comorbidities and mortality. The aim of the study was to evaluate the prevalence of musculoskeletal pain and associated factors in the elderly population. This is a cross-sectional study, using data from the Elderly Cohort Project in Bagé-RS: health situation and relationship with the Family Health Strategy (FHS), carried out during the 2016/2017 follow-up. The sample consisted of 735 elderly people, aged 68 or over, residing in the area covered by primary health care services in the urban area of the municipality of Bagé / RS. The Nordic Musculoskeletal Questionnaire (NMQ) was used to analyze prevalence of pain in the upper limbs, spine and lower limbs and to verify associated factors. Information on the symptoms in these regions of the body was used. The majority elderly of whom were female (65.4%) aged between 68 and 79 years (68.7%) and white skin color (82.2%). Prevalence of musculoskeletal pain in the spine was 42.5%, 33.7% in the upper limbs and 31.0% in the lower limbs. In the crude and adjusted analysis association of pain was maintained with the presence of multimorbidity, greater satisfaction with health and use of emergency services in the last year. The results of this study reinforcing the pattern of pain and musculoskeletal symptoms in the elderly and justifying the need for training professionals and health services to serve this growing portion of the population.


Introduction
Pain is conceptualized as a bad sensory and emotional experience, a symptom of an underlying disease with tissue damage, or a primary condition, where there is emotional and functional impairment without previous disease (Treede et al., 2019). In turn, musculoskeletal pain affects functionality and is a source of stress, prolonged suffering and drug abuse, becoming a problem for the individual, his/her family and the health system (Andrade, F. A., Pereira, L. V. & Sousa, 2006).
In the elderly, musculoskeletal pain is even more impacting, affecting functional capacity, which can lead to high levels of fragility, comorbidities and mortality (Gold & Roberto, 2000). In addition, pain is among the main symptoms that reduce the likelihood of the elderly maintaining their daily activities, reduces interactionwith other people, and increases social isolation (Celich & Galon, 2009).
As for factors associated with musculoskeletal pain, there are those considered intrinsic: female gender, advanced age, white skin color, hormonal deficiency, presence of comorbidities, genetic factors, fragility or history of previous fracture, weakness of lower limbs, deficit of balance and polypharmacy; and those considered extrinsic: low body weight, physical inactivity, time of exposure to tobacco, alcohol abuse (Bello et al., 2014;Curtis et al., 2015).
Considering the magnitude of the problem and the impact on the quality of life of the elderly, it is essential that studies on the subject are published, in order to guarantee that researchers and professionals who study the subject and work caring for the elderly population, especially in the elderly. can update their knowledge regarding preventive and rehabilitation care (Miranda et al., 2012;Mody & Brooks, 2012).
In this sense, the objective of the present study was to evaluate the prevalence of musculoskeletal pain and associated factors in the elderly population living in the urban area in Southern the an Brazilian..

Methodology
This is a descriptive and analytical study, with a cross-sectional analysis, (Bonita, R., Beaglehole, R., & Kjellström, T, 2010;Pereira, A. S., Shitsuka, D. M., Parreira. F. J., & Shitsuka, R, 2018) with data from the Bagé-RS Elderly Cohort Project: health situation and relationship with the Family Health Strategy (FHS) -(SIGa-Bagé). The sample consisted of elderly people, aged 68 or over, residing in the area covered by primary health care services in the urban area of the municipality of Bagé / RS.
The municipality of Bagé is located in the southern part of the state of Rio Grande do Sul (RS), on the border with Uruguay, with a territorial area of 4.093.582 km and a demographic density of 28.52 inhabitants / km². In 2008, 12.0% of the population of Bagé were elderly people aged 60 or over, with a total of 14.1% estimated for 2020 (IBGE, 2020).
Data were collected for the first time in 2008 and the initial sample was selected by systematic searching in the coverage areas of the municipality's 20 Primary Healthcare Centers (PHCs) (15 followed the FHS model and 5 followed the Traditional model). All individuals 60 years of age or older, residing in the selected households, were considered eligible and invited to participate in the research. Among the 1.713 elderly selected, 1,593 were interviewed, with 852 resident in the FHS coverage areas and 741 resident in the Traditional PHC coverage areas (Thumé et al., 2011). Between August 2016 and September 2017, using the list with the names and addresses of the elderly people sampled in 2008, all participants were contacted and invited to participate again in the study, thus constituting the cohort called Saúde do Idoso Gaúcho de Bagé (SIGa-Bagé). This study used the data collected in 2016/2017. The interview was conducted at the elderly people's homes, by trained and qualified interviewers, by filling out a structured questionnaire with pre-coded questions, standardized and previously tested, using an electronic device -Personal Development Analysis (PDA). Elderly people who, during the data collection period, were identified as dying, no longer lived in the same city, lived in Long Term Care Institutions or were prevented from responding by court order were excluded.
To analyze prevalence of pain in the upper limbs, spine and lower limbs and associated factors, complete information on the symptoms in these regions of the body was used, obtained via the Nordic Musculoskeletal Questionnaire (NMQ) (Kuorinka et al., 1987) validated in Brazil in 2002, as a standard for measuring reported musculoskeletal symptoms (Maia et al., 2018).
The dependent variable was investigated by asking the following question: "In the last 12 months have you had problems (such as pain, tingling and numbness) in: neck / cervical region, shoulders, arms, elbows, forearms, wrists / hands / fingers, region back, lumbar region, hip / lower limbs?", with options for dichotomous responses (no / yes). To this end, the respondents were shown an illustrative figure of the human body to observe the regions of the body and answer the question.
For analysis purposes, the variable was divided into pain in the upper limbs (neck / cervical region, shoulders, arms, elbows, forearms, wrists / hands / fingers), pain in the spine (dorsal region, lumbar region) and pain in the lower limbs (hip / lower limbs). Presence of pain in at least one of the body regions included in the variables "pain in the upper limbs", "pain in the spine" and "pain in the lower limbs" was considered to be an affirmative answer.
The first level consisted of demographic variables (gender; age; skin color); socioeconomic (marital status; education, economic class -ABEP, work / retirement); the second level contained behavioral variables (level of physical activity, smoking, alcoholism); the third level contained health perception and health situation (morbidities) variables; the fourth level contained ADL and IADL variables; the fifth level contained the variables regarding use of health services in the last year (emergency room, primary healthcare center, private service).
Was used to analyze the data the Stata® version 14.0 (StataCorp / College Station, United States). A significance level below 5% was adopted for two-tailed tests. Their respective confidence intervals (95% CI) were used to calculate crude and adjusted Prevalence Ratios, and the p-values of the Wald test for heterogeneity and linear trend were measured. Backward adjustment by hierarchical levels was used, keeping only those with p≤0.20 in the model, through Poisson regression with robust adjustment of variance.

The protocol for this study was approved by the Health Research Ethics Committee at the Federal University of
Pelotas under protocol no. 678.664. The ethical principles established by the National Health Council were followed in accordance with its Resolution No. 466/12. Study participants were informed of their right to refuse participation and about confidentiality procedures. Those who agreed to participate in the study signed an Informed Consent Form.

Results and Discussion
The 1,036 elderly people were located, of these 81 were refusals (5.1%) and 220 losses (13.8%) (including losses in data transfer, not located, institutionalized and those who moved to another municipality), totaling 735 elderly people interviewed.

Discussion
The findings indicate high prevalence of the outcomes studied. Pain in the upper limbs was associated with females, the presence of two or more diseases, difficulty in performing instrumental activities of daily living, use of emergency services and primary care. Spinal pain was associated with the use of emergency services, a result similar to lower limb pain, which was also associated with difficulty in performing instrumental activities of daily living.
The results of this study corroborate the data in the literature, which report higher occurrence of pain in the upper limbs among females (Dellaroza & Pimenta, 2012;Esquenazi et al., 2014;Melo et al., 2017). Women perform more domestic tasks and during life are exposed to ergonomic loads, mainly repetitiveness, forward head posture and working at high speed. The female gender has some anatomofunctional characteristics such as less muscle mass, less bone mass, more fragile joints and being less adapted to strenuous physical effort. These characteristics may be related to higher prevalence of pain in the upper limbs (Ferreira et al., 2011).
With regard to morbidities, elderly people with two or more morbidities were more likely to develop musculoskeletal pain in the upper limbs. As diseases affect the cardiovascular, musculoskeletal, endocrine systems, among others, presence of pain can be twice as high among elderly people who reported two or more morbidities due to their negative impact on health.
Our results revealed that difficulty in performing IADL has been shown to be associated with pain in the upper and lower limbs, corroborating with the literature we researched (Dellaroza et al., 2013;Dellaroza & Pimenta, 2012). Pain may be due to physiological changes in the aging process, pathologies and/or problems associated with this age group. According to the World Health Organization, after 70 years of age, 30% of the elderly have some chronic disease and also: among those with this type of disease, around 50% have some type of limitation or physical disability (Reis & Torres, 2011). The progression of chronological age, together with the aging process, is directly related to higher levels of functional disability, a fact described in the literature (Del Duca et al., 2009). However, the possibility of reverse causality bias must be considered, since the study design does not allow identification of whether the occurrence of exposure was prior to the outcome.
Use of emergency services in the last year was associated with the presence of pain in the spine and also in the upper limbs of the elderly studied, while seeking PHC services was shown to be associated only with pain in the upper limbs.
Regardless of the possibility of reverse causality, this result reinforces the importance of the outcomes studied in terms of the demand they cause for health services. In addition, it is important to highlight the greater use of emergency services, a result that may reveal weakness in continuous monitoring by primary care of cases of elderly people with musculoskeletal pain, which leads to the worsening of their pathological condition, and the need to seek pain control via emergency services (da Silva et al., 2016;Silveira & Paskulin, 2014).
Being satisfied with health has proven to be a protective factor for back and lower limb pain, as has good quality of life for pain in the upper limbs. People with poor/very poor self-rated health are about three times more likely to have chronic spine problems (Romero et al., 2018). Self-assessment of health status is a subjective indicator of the individual's perception of their own health, expressing physical, emotional, well-being and satisfaction with their own life (Melo et al., 2017).
Regarding marital status, the results show that widowed elderly people are less likely to develop pain in the upper limbs, when compared to married and single elderly people, going against the findings of other studies, where the authors refer that the feeling of loneliness, as in widowhood, could cause anguish, vulnerability, loss of control and, consequently, worsening or perpetuation of pain. It is believed that this finding is linked to lower commitment of widowed elderly people to their partner's care activities and also to the possibility of these elderly people receiving greater family support when compared to the other elderly people in the study (80 years of age or older) who had lower probability of pain in the lower limbs, going in contrast to that found in most studies, where the elderly have high prevalence of pain in that area (dos Santos et al., 2016;Feltrin et al., 2015).
Our results also identified higher prevalence of pain in the lower limbs among the elderly over 80 years of age. It is known that there is a reduction of approximately 30% in lean mass and joint mobility among elderly people in this age group.
These are factors that can lead to difficulty and pain in performing activities that require physical performance, such as walking, climbing stairs, lying down and getting out of bed, bathing, dressing and doing some physical exercise (Bortoluzzi et al., 2017).
Among the positive points of this study, we highlight the sample size, the collection of primary data and the low rate of non-response. Although the data came from a cohort study, the analyses did not assess the incidence of outcomes establishing the temporal relationship, making it impossible to verify, for example, whether the presence of morbidities precedes the appearance of muscle pain.

Conclusion
The analyses proposed in this study sought to broaden the discussion about the prevalence of musculoskeletal pain and its associated factors among the elderly. Despite the evidence in the literature pointing to a pattern of this profile, over the years there seems to be perpetuation of little training or scarce training of health professionals, insufficient availability of specialized services and inefficient or little explored prevention to attend this growing portion of the population. The importance of further studies on the subject is highlighted, given the difficulty in obtaining data related to clinical and epidemiological characteristics, in addition to bringing possible negative implications on the quality of life of the elderly, in order to provide greater support with regard to the demands and planning preventive services related to changing lifestyle, carrying out healthy activities and tracking diseases in asymptomatic periods.