A large population of urban older adults were recruited and assessed for individual characteristics, which were stored in a database for cross-study research on the correlation between sarcopenia, LS, and biomarkers and the risk for falls and immobility in older populations. The project was funded by Thai Health Promotion and approved by the Vajira Institutional Review Board.
Study design
This was a population-based cohort study that enrolled adults age 60 years or older who lived in one of five subdistricts of the Dusit District, Bangkok, Thailand, between October 1, 2019, and September 30, 2021.
The present study had three phases of data collection:
Phase 1: This phase included subject identification and terminology clarification. Experts from Thai Health Promotion, Navamindradhiraj University, Thai College of Emergency Physician, Medical Service Department of Bangkok (20 participants), and the Head and Member of Community Health Promotion Volunteers for each subdistrict (46 participants) met to clarify the association between falls and health status. Research assistants (RAs) obtained data on older adults aged ≥60 years who resided in the area and were willing to participate. In Bangkok, health promotion volunteers are employed by the Bangkok Metropolitan Council to work on health promotion at the subdistrict level. They conduct surveys on health status and family members and report data to the Bangkok Department of Health. RAs coordinated the schedule.
Phase 2: At each community site, the principal investigator (PI) and RAs collected data on baseline characteristic and distributed fall calendar postcards and fall risk identification cards reporting the “Stopping Elderly Accidents, Death and Injuries” (STEADI) [30]. Examinations and laboratory investigations were scheduled for one month later.
Phase 3: RAs performed telephone follow-up at 3, 6, and 12 months, which is the gold standard protocol for falls. Respondents answered questionnaires about the activities of daily living, history of falls, rating of the emergency department, hospitalization, and mortality. The results were submitted to the Head of Community and the Department of Health to generate a screening tool and health system for reducing fall occurrence. The subgroups of the cohort were invited to address questions related to the mechanism and prevention of falls, including the correlation between falls and muscle mass and sarcopenia based on ultrasound muscle. A second project determined the prevalence of dehydration and developed a new protocol for older adults.
Recruitment process
The Head of Community Health Promotion Volunteer announced the project to each subdistrict and recruited older adults who were interested in participating and met the following criteria: aged ≥ 60 years old, able to walk, and expected to live in the community for at least 2 years. When there were at least 30 participants in a subdistrict, RAs conducted a screening at the community meeting place to determine eligibility. The inclusion criteria were adults ≥ 60 years old who lived in Dusit District, could walk at least 6 meters, and were expected to live in the community for at least 2 years. The exclusion criteria were older adults who were unable to speak Thai, had severe cognitive impairment of >12 points on the six-item cognitive screening test [31], or were blind or deaf.
Data collection (Table 1 and Figure 1)
Data on baseline characteristics, underlying diseases, medications, Charlson comorbidity index [32], Barthel activities of daily living index [33], Mini Nutritional Assessment (MNA) [34], cognitive function, World Health Organization Quality of Life (WHOQOL-BREF-THAI) [35], frailty phenotype [36], mobility, fall history, and end of life decision were collected for each participant. RAs obtained written informed consent from each participant. Participants received $8 USD for each community visits and $15 USD for the hospital appointment. Transportation was provided based upon request. Details of data collection methods are shown in Table 1 and Figure 1.
Table 1
Data collection
Domain
|
Community site interview
|
Demographics
|
Sociodemographic information
|
Falls
|
History of falls, fracture, and injuries
STEADI checklist
Fall risk medications
Home environment
|
Frailty
|
Frailty phenotype [36]
|
Footwear
|
Footwear/shoe wear
|
Nutrition
|
MNA
|
Medications
|
Medication inventory (prescription, over-the-counter drug, herbal, or supplemental)
|
Comorbidity
|
Charlson comorbidity index [32]
|
Cognition
|
Six-item cognitive screening test [31]
|
Quality of life
|
WHOQOL-BREF-THAI [35]
|
Behaviors
|
Alcohol use, smoking, water or other drink
|
Pain
|
Pain location and characteristics
|
Disability
|
Barthel activities of daily living index, LS checklist [37]
|
Community site interview
Five trained RAs performed extensive interviews at the community sites and evaluated health status based on Charlson comorbidity index (self-reported physician diagnosis and confirmation by hospital medical records), sociodemographic information (age, gender, marital status, profession, monthly income, caregiver, family member, level of education, and electronic device for communication), disability (Barthel activities of daily living index), cognitive test (six-item cognitive screening test), and quality of life (WHOQOL-BREF-THAI).
Nutritional assessment [34]
Nutritional assessment was based on weight, height, body mass index, mid-arm circumference, and the MNA. The MNA score in the elderly can determine adequate nutritional status (MNA, ≥ 24), malnutrition risk (MNA, 17–23.5), and protein–calorie malnutrition (MNA, < 17). The MNA had high sensitivity (96%) and specificity (98%) for identifying patients who were at risk for malnutrition (MNA, 17–23.5).
Frailty [36]
Frailty was evaluated using the “frailty phenotype,” [36] which has a set of five criteria: involuntary weight loss of 4.5 kg over the past year, self-reported exhaustion, slow gait speed, poor handgrip strength, and low physical activity. The results were classified as follows: not frail, no criteria present; pre-frail, one or two criteria present; and frail, three or more criteria present.
Medications
A medication review was performed at a community visit. RAs examined all containers for prescription, over-the-counter, and herbal medicines used in the previous month, and the name, daily dose, and strength were recorded. Upon hospital examination, PI confirmed the RAs’ record of medication used with the hospital electronic medical record system.
Fall assessment
Fall evaluations were determined based on the STEADI guideline and geriatric emergency department guideline. The home environment was assessed based on a checklist to assess for fall hazards such as imbalanced stair, improper lighting in the hallway, hand drill in the bathroom, and slippery floor.
Quality of life [35]
WHOQOL-BREF-THAI was used to evaluate the individual’s perception of participants in the main concept of their goal, expectations, and value of life. It has 26 items assessed on a scale of 0–5. Therefore, the final score can range from 0 to 130. Four domains are evaluated: physical health, psychological well-being, social relationships, and the environment. Our study modified the score for each domain to 0–100, following the WHO recommendations. A higher score indicates better perception of quality of life.
Clinical examination
Evaluation for clinical examination was performed by three emergency physicians who had experienced taking care of older adults for at least 5 years, three RAs who had a bachelor’s degree in health science, and experienced nurse practitioners. Before the examination started, one physiatrist trained all physicians and RAs to evaluate their physical performance. The examiner was carefully evaluated and gave participants 5–10 minutes of rest before each step of evaluation to avoid overexhaustion.
Mobility performance, muscle strength, and musculoskeletal examination
The purpose of examination was to assess muscle strength and muscle power, especially of the proximal muscle. The mobility performance assessment during hospital visit included time taken to get up and go and the 4-meter test. LS was established and defined by the Japanese Orthopedic Association in 2007 as a state of degraded mobility due to impaired locomotive organs, which increases the risk of disability. Decreased motor function and musculoskeletal pathologies include degenerative spondylosis and spinal stenosis. LS in this study was defined using a geriatric locomotive function scale of 25 questions (GLFS-25) [37]. A score of ≥ 16 indicates LS. The study showed that GLFS-25 is associated with decreased gait speed and a risk of falls [13,14].
Fall evaluations
During hospital visits, RAs recorded orthostatic vital signs, the time taken to get up and go [39-41], physical performance [38,42-45], somatosensory function, and ultrasound muscle mass.
Each participant received a telephone follow-up at 3, 6, and 12 months.
Physical performance [42-45]
The lower extremity mobility performance was evaluated using the Short Physical Performance Battery (SPPB) [38]. The SPPB measures the total time taken to perform the sit to stand test five times, 4-meter walking speed [41], and balance while standing. The full range was based on a scale from 0 to 12.
Berg balance scale
The Berg Balance Scale consists of 14 balance tasks. The scale has been validated as a fall risk assessment tool for community-dwelling older adults.
Somatosensory function test
Light touch was evaluated using Semmes–Weinstein monofilament test (size, 5.07; weight, 10 g). We tested the greater toe and the head of the first, third, and fifth metatarsal areas. The test results were categorized as sensory deficit and no deficit.
Sarcopenia [46]
Sarcopenia was defined as an age-related loss of skeletal muscle, decreased muscle strength, and low physical performance. For identifying patients at risk for sarcopenia, we followed the Asian Working Group for Sarcopenia 2019 criteria for diagnosis.
Criteria for sarcopenia diagnosis
Grip strength was evaluated using the grip dynamometer model TK-1201 (TAKEI KIKI KOGYO, Japan) (male, < 28 kg; female, < 18 kg). Physical performance was evaluated based on a 6-meter walk (< 1.0 m/s) or 5-time chair stand test ( ≥ 12 seconds). Appendicular skeletal muscle mass (ASM) was evaluated using BIA (male, < 7.0 kg/m2; female, < 5.7 kg/m2). Sarcopenia was defined as having low ASM plus low muscle strength or low physical performance. Severe sarcopenia were defined as having low ASM plus low muscle strength and low physical performance.
Dehydration [25]
We performed a blood test to test the hydration status. Hypertonic dehydration was defined by serum osmolality: current dehydration (>300 mOsm/kg), impending dehydration (295–300 mOsm/kg), and normal hydration (275 to <295 mOsm/kg).
Statistical analysis
Statistical analysis was performed using STATA version 15.0. A descriptive statistic was used for the baseline demographic data. We implemented a survival analysis as part of a prospective analysis to assess the risk of falls associated with the risk of sarcopenia and dehydration (not presented in this paper). It is beyond the scope of this study to present all plan analyses performed for the Bangkok falls study; therefore, we have described a standard methodology that will be used as part of our research. The incident of falls will be identified using a new case of a fall with a recurrent fall, which has been presented as a cumulative rate. We analyzed the time to first fall using a survival analysis. Multivariate analysis was used to estimate the relative risk of falls. We used a general linear model to depict repeatedly ordinal outcomes with correlated responses, such as Poisson regression. Other analyses included structural equation modeling to determine whether there are latent variables, as defined by share covariate potential fall risk factors.