EXAMINING THE ASSOCIATIONS BETWEEN LEAN MASS, MUSCULAR STRENGTH, MUSCLE QUALITY AND PHYSICAL FUNCTION

Objective: The determinants of physical function are not well characterized among middleaged women. The primary aim of this cross-sectional study was to determine the strength of the associations between lean mass, muscular strength, muscle quality, and physical functional ability in a cohort of middle-aged women. The secondary aim was to determine the measure of muscle quality most highly associated with measures of physical function. Methods: Middle-aged women (N=111, age, 53.14 ±6.15 years) had body composition (via dual energy x-ray absorptiometry), physical activity (via accelerometer), and physical function (via Transfer Task (TRANSFER), 30-Second Chair Stand (30-CS), 6-Minute Walk Test (6MWT), 8-Foot-Up-And-Go (UP-GO)) assessed objectively. A lower body physical function composite score was also calculated. Lower body strength was measured using isokinetic dynamometry for isometric knee flexion and extension at 60 degrees, isokinetic flexion and extension at 60 degrees per second, and isokinetic flexion and extension at 180 degrees per second. Muscle quality was defined as muscular strength normalized for upper leg lean mass and calculated using: 1) isometric knee flexion and extension at 60 degrees (MQ-ISO), 2) isokinetic knee flexion and extension at 60 degrees per second (MQ-KN60), 3) isokinetic knee flexion and extension at 180 degrees per second(MQ-KN180). Results: The lower body physical function composite score was significantly associated with percent lean mass, MQ-ISO, MQ-KN60, and MQ-KN180. Partial correlations, controlled for age and average steps per day, found that MQ-KN60 was the variable most highly associated with the physical function composite score. Results from a hierarchical linear regression showed that 1) age, average steps per day, and MQ-KN60 are independently associated with physical function composite score, explaining 3%, 18.1% and 14.3% respectively, and 2) age, average steps per day, MQ-KN60 were significantly associated with , TRANSFER, 30-CS, and 6MWT. Conclusion: In middle-aged women, percent lean mass, muscular strength, and muscle quality were all significantly associated with physical functional ability. The association between MQ-KN60 and the physical function composite score was stronger than all other measured variables. This data provides insight into the most relevant measures to consider when examining the independent contributors to physical functional ability in middle-aged women.

million (1). Recent studies report that middle-aged adults, specifically middle-aged women, self-report difficulties performing daily activities and have poor physical function (2)(3)(4), where up to 25% of women between the age of 42 and 52 years old (2).
Physical function performance is an aspect of quality of life, defined as the ability to perform the basic actions that are essential for maintaining independence (5). Extensive research assessing physical function in older adults demonstrates that physical function performance is associated with physical activity level (6), lean mass, and muscular strength (5,(7)(8)(9)(10), however significantly less is known about physical function in middleaged adults.
While lean mass and muscular strength are independently associated with physical function, examining a measure that accounts for both variables may be the most comprehensive approach to understanding the association between these variables and physical function outcomes. One way to examine the association between lean mass and muscular capacity is by calculating muscle quality. Muscle quality is defined as the ratio of muscular capacity to lean mass (11). Muscle quality assesses the association between muscular strength and lean mass, therefore it may be an optimal independent variable to examine when evaluating determinants of the changes in physical function, compared to lean mass and muscular strength alone (12).
Previous research in older adults has examined how lean mass, muscular strength, and muscle quality, change with age and how these variables are associated with physical function (13)(14)(15). Limited research has examined these associations in middle-aged adults, especially middle-aged women (4,16). This is significant because in previous studies, as many as 25% of women are reporting physical functional limitations during mid-life (2). Additionally, negative changes in body composition and muscular capacity often begin during middle-age (5,8,9,11,17) making it important to understand how the associations develop and which factors most affect physical function. Analyzing these factors during middle-age would allow for better understanding of the association between muscle mass, muscular strength, muscle quality and physical functional ability.
Therefore, the primary aim of this study is to examine the strength of the associations between muscle mass, muscular strength, muscle quality and objective measures of physical function performance in a cohort of middle-aged females, when controlling for age and physical activity level. It is hypothesized that measures of muscle quality will be more strongly related to measures of physical function performance compared to measures of muscle mass and muscular strength. As muscle quality takes into consideration both the structural and functional ability of the muscle, it may have the strongest impact on physical function performance compared to muscular strength or lean mass alone.
The secondary aim of the study is to compare muscle quality calculated using three different muscular strength measures, to determine which measure is most highly associated with objective measures of physical function, when controlling for age and physical activity level. Strength will be measured by isometric knee strength at 60

Introduction
The US Census Bureau estimated that in 2014, 83 million Americans were between the age of 45 and 64 years old (1). While middle-aged women make up a significant portion of the population, they are significantly under-represented in research, even with recent efforts to correct this imbalance (18). In general, the hormonal changes associated with menopause are often cited as the primary challenge for including middle-aged women in research (18).
Most women go through menopause between 45 and 55 years of age and undergo significant hormonal changes including decreases in estrogen, IGF-1 and DHEA (19).
These hormonal changes are associated with several negative health outcomes, including a decrease in muscle mass (19)(20)(21). Changes in muscular capacity, including muscular strength, endurance and power, have also been associated with age-related changes in sex hormones (19)(20)(21)(22). Due to the current life expectancy, it is possible that a woman could spend 30 or more years with a decreased level in sex hormone compared to younger levels, resulting in a significant reduction in muscle mass and muscular capacity (20,21,23), which puts women at a high risk for disability and other health conditions.
Menopause has been associated with declines in physical function performance (24,25). This is concerning because low levels of physical function are associated with an increased risk of developing chronic health conditions (3,24,26). Therefore, it would be prudent to assess physical function during this time period. Currently there is a significant gap in the literature regarding objective physical function performance in middle-aged women, as the majority of the work examining physical function in this age group relies on self-report measures (3,27,28).
It is important to understand the factors that independently contribute to physical function in order to understand changes in physical functional ability across the lifespan.
Factors related to muscular capacity such as muscular strength, muscle mass and muscle quality are important to consider when assessing physical function. Muscle quality, a unique measurement that considers both measures of muscle mass and muscular strength, may be more strongly related to physical function performance compared to the assessment of muscle mass or muscular strength alone (11). The associations between muscle mass, muscular strength, muscle quality and physical functional ability have been well established in older populations (11,(29)(30)(31)(32), but a significant gap in the literature exists when it comes to these associations in middle-aged women. Therefore, analyzing the factors associated with physical function during middle-age would allow for better understanding of the significance of these associations and may allow for early intervention before the onset of physical limitations.

Physical Function
Physical function is the ability to perform the basic actions essential for maintaining independence (5). Physical function has been previously associated with the ability to perform activities of daily living, chronic health conditions, and overall health status across the lifespan (3,24,33).
Physical function can be assessed both subjectively and objectively. The most common subjective measure of physical function is the Medical Outcomes Survey Short Form 36 (SF-36) questionnaire (34). The portion of the SF-36 that assesses physical function includes 10-items which evaluate activities ranging from limitations during daily tasks such as carrying groceries or climbing stairs, to the ability to perform moderate and vigorous activities (35). The most common objective measures of physical function include the Short Physical Performance Battery Test (SPPB), the Timed Up-and-Go (TUG), Gait Speed, 5-Chair Stand, and the 6-Minute Walk test (6MWT) (36). Each of these physical function assessments is associated with an aspect of health-related physical fitness. For example, the time it takes to complete 5 consecutive chair stands is highly associated with muscular strength, and both gait speed and 6MWT have been highly associated with cardiorespiratory fitness levels (36). Commonly used physical function assessments are described below: Short Physical Performance Battery (SPPB): The SPPB consists of three tasks: 4-Meter Gait Speed, Balance Assessment (which includes tandem and semi-tandem stance), and a 5-Chair Stand. This assessment is predicative of fall risk and disability in adults over the age of 70 years (36). The SPPB was specifically designed for older adults and is not appropriate for assessing physical functional ability in middle-aged adults.
Timed-Up-and-Go (TUG): The TUG measures the amount of time it takes a participant to stand up from a chair without the use of their arms, walk 3 meters, and return to a seated position in the chair (36). The TUG is associated with muscle power and balance (37), and is also predictive of fall risk in older adults (36

Physical Function and Health Status
Poor physical functional ability is associated with the development of chronic health conditions (41) and increased risk of physical disability (41,42) later in life, however, most of this research has been conducted with older adults.
One of the few studies that addressed physical function and health status in middleage women was completed by Karvonen-Gutierrez et al. (2). This secondary analysis of the Study of Women Across the Nation (SWAN) data assessed the risk of disability in 326 women between the age of 55 and 68 years. Self-reported disability was measured using the World Health Organization-Disability Assessment Schedule (WHO-DAS), an international standardized measure of disability designed to compare the prevalence and determinants of disability across different populations. Twenty-five percent of the cohort reported moderate, severe, or extreme disability, which indicates that middle-age may be an appropriate time to assess factors affiliated with physical disability so that effective interventions aimed at improving these outcomes in middle-age can be designed and implemented (2,24).
Another study which examined the association between physical function and disability is a secondary analysis of a larger longitudinal study (28). Men and women (n = this study found that women reported higher levels of disability compared to males, and a significant association existed between physical functional and disability, it suggests that physical functional ability should be further studied in women. The association between physical functional ability and health status is well represented in the older adult literature (10,21), but significantly less is known about this association in middle-aged adults. However, studies that assess the association between physical function and health status in middle-aged adults agree that lower physical functional ability is associated with an increased risk of disability (2,28).

Aging and Physical Function
Overall, previous research agrees that a significant association between age and physical functional ability exists. However, these studies primarily focus on physical function in older adults and use physical function assessments that have been validated for that population (27,29,43).
A 5-year study by Bouchard et al (43) supports the association between age and physical function in older adults. In both sexes, age was the most important contributor to balance performance measured by the Romberg test. Woods et al. (29) supports the association between physical function and age; women with lower physical function (measured via TUG and 6-Meter Walking Speed) were significantly older than the women with higher levels of physical function.
One of the few studies assessing physical function exclusively in middle-aged adults determined the association between physical functional ability (measured via 30-CS, UP-GO, 6MWT) and age in women between 45 to 65 years (44). This study found an independent association between age, UP-GO, and the 30-CS, in which older age was independently associated with lower physical function performance. Even at mid-life, physical function is significantly associated with age and those who are older perform more poorly on objective measures of physical function.
Another study which assesses middle-aged adults is using the U.S. National Health and

Muscle Mass and Physical Functional Ability
Aging A significant body of research examining the changes that occur in muscle mass with age exists (7,8,10,31,46,47 between men and women and that muscle mass peaks earlier than mid-life in women. Results from a cross-sectional study performed by Janssen et al. (48) supports the association between age and skeletal muscle mass. They found that age was negatively associated with total and upper body muscle mass. When examining difference between upper and lower body muscle mass between age groups (both sexes were divided into: 18-44 years and ≥45 years old), both upper and lower body muscle mass were significantly associated with age (lower body: r =-.48, upper body: r =-.26) in women, but was only significantly associated with lower body muscle mass (r =-.48) in men. However, for both sexes, age was more highly associated with lower body muscle mass compared to upper body muscle mass.

Physical Function
The majority of the studies examining the association between muscle mass and physical function have been conducted with older adults (49)(50)(51)(52). A cross-sectional study performed by Reid et al. (51) assessed the association between total leg lean mass and physical ability in a cohort of 57 older adults (mean age of 74.2 years). Total lean leg mass was independently associated of mobility disability after correcting for confounding variables, such as chronic medical diagnoses, bone mineral density, body weight, total body fat, and habitual physical activity (p<0.05).
Another study which supports the association between muscle mass, mobility limitations, and disability was a secondary analysis assessing a cohort of 2,631 older adults from the Health ABC study (52). Lower muscle mass (those in the lowest quartile of muscle mass cross sectional area) at baseline increased the risk of developing mobility limitations within the 3 year follow up, as men with lower muscle mass were 2.25 times and women were 1.7 times more likely to develop mobility limitations at follow-up compared to individuals in the highest quartile of muscle mass. The results from this study indicate that low muscle mass significantly effects mobility over a relatively short period of time.
The association between low muscle mass and poorer physical functional ability has been well established in older adults (49)(50)(51)(52). However, literature assessing the association between muscle mass and physical function in middle-age adults is limited (24).
In a cross-sectional study performed by Charlier et al. (56) significant associations between age and measures of strength were observed in both sexes. In women, skeletal muscle strength was 28.7% lower in the 60-70-year-olds compared to 18-29-year-olds.
After the age of 70, muscular strength was 52.2% lower compared to the 18-29-year-old group.
A 3-year longitudinal study by Goodpaster et al. (15), also supports the association between muscular strength and age. Baseline body weight and measures of total lean mass, leg regional lean mass, and thigh cross-sectional area were negatively correlated with the changes in muscular strength at follow-up.
Work by Delmonico et al. (13) supports the association between muscular strength and physical function older adults. Significant declines in average torque of the knee extensors measured at 60 degrees per second were seen in both men and women over the  The association between muscular strength and physical functional ability in middle-age is not well examined, but the association exists in older adults. Understanding the association between muscular strength and physical functional ability in middle-age would allow insight into a possible explanation why physical function declines in middleage. If an association is established, it could provide a possible intervention strategy to help reduce the decline of physical function later in life.

Muscle Strength and Physical Function in Middle-Aged Adults
The small body of literature that assesses muscular strength and physical function With the decline in muscular strength starting at an earlier age and declining at a faster rate at the end of mid-life for women, the assessment of muscular strength with physical function is important when assessing health risks and disability. Thus, understanding the best method for strength assessment and how muscular strength relates to physical functional performance is important to examine in cohorts of middle-aged women.

Defining Muscle Quality
Muscle quality is a unique measurement that does not yet have a universal definition (60). In exercise science, muscle quality is often defined as a measure of muscular strength or power normalized for muscle mass (54,60). Muscle quality combines both measures of muscle capacity and muscle mass and may be more highly related to physical function ability compared to the measurement of muscle mass or muscular strength alone (11,60). However, the lack of a universal definition has led to inconsistent findings in the literature (61,62).

Age-Associated Decline in Muscle Quality
A cross-sectional analysis of objectively measured muscle mass, muscular strength and muscle quality in 654 participants between the ages of 18 and 93 years found significant age and gender associations with measures of muscle quality (p<0.001) (63). Muscle quality decreased with age, and women had significantly lower muscle quality compared to men. This demonstrates the age and sex differences in muscle quality, suggesting the importance of understanding muscle quality in both men and women across the lifespan.
In a longitudinal study by Metter et al. (61), age-related declines in muscle mass, muscle strength and muscle quality (p<0.001) were evident. However, muscle quality stayed relatively constant after 30-39-years of age. This differs from previous work examining these variables across time, as one study found an age associated decline in muscle quality starting at age 20 (63), demonstrating disagreement among studies examining age-related changes in muscle quality.

Muscle Quality and Physical Function
Evidence supports the association of muscle quality and physical function across

Conclusion
Poor physical function ability is associated with an increased risk for the development of chronic diseases and disability (28,41,42). Physical function has been studied extensively in older adults, but significantly less research has been done examining physical function in middle-aged adults. In order to fully understand physical function and its determinants in middle-aged adults, muscle mass, muscular strength, and muscle quality should all be assessed, as all have been found to be independently associated with physical functional ability (13,49,66,68) and each have been separately associated with adverse health outcomes (8,50,51,64,69). Procedures: Interested participants completed an online survey to determine eligibility.
To be eligible, participants had to be a woman between the ages of 40 and 64 years old.
Additionally, all participants were required to speak and read English, be weight stable Menopausal Status: Menopause status was obtained by self-report, and then classified according to the SWAN criteria (24,25).
Body Composition: Dual Energy X-ray Absorptiometry (GE Lunar iDXA, Waukesha, WI) was used to assess body composition (fat mass, percent body fat, and lean mass).
Upper leg lean mass was also assessed and was defined as lean mass contained within the area between the neck of the femur and the medial and lateral condyles of the femur. Outlying values were identified as greater or less than 3 SD from the mean.
Pearson correlations were conducted to examine the associations between age, BMI, percent fat mass, percent lean mass, average moderate and vigorous physical activity per day, average steps per day, isokinetic peak torque at 180 degrees/second, isokinetic peak torque at 60 degrees/second, isometric peak torque at 60 degrees, MQ-ISO, MQ-KN180, MQ-KN60, TRANSFER, UP-GO, 30-CS, 6MWT, and the physical function composite score.
Next, partial correlations, controlling for age and average steps per day, were conducted to assess the strength of the associations between muscle quality and measures of physical function. Finally, linear regression was used to identify the independent contribution of muscle quality to physical function (composite score and individual assessments of physical function), while controlling for age and physical activity (steps/day). Regression analyses were conducted in the following order, with the addition of a new variable with each step: 1) age; 2) steps/day; 3) specific measure of muscle quality. All data are presented as mean (SD) and all statistical significance were set at  To determine which physical activity measurement to use when controlling for physical activity level, average daily minutes of moderate to vigorous activity and average steps per day were both examined. Average steps per day was slightly more strongly correlated with the physical function composite score (r=0.39, p<0.001) compared to average daily minutes of moderate to vigorous physical activity (r=0.38, p<0.001), and therefore used in further analyses.
Partial correlations, controlled for age and average steps per day, are presented in Table 2. Both MQ-KN60 and MQ-KN180 were significantly associated with physical function composite score (p<0.001), however MQ-KN60 was more strongly associated with the physical function composite score (r=0.43) compared to MQ-KN180 (r=0.40).
As both muscle quality measurements were significantly correlated with physical functional ability, a regression analysis for each measurement of muscle quality was performed to assess the independent associations with physical function measurements. Tables 3 and 4 provide the results for the hierarchical linear regression assessments for muscle quality and physical function.

CONCLUSION
The current study assessed the associations between measures of muscle mass, muscular strength, muscle quality, and physical functional ability in middle-aged women.
The major findings from this analysis were that: 1) muscle quality is more highly associated where lower angular velocity allow higher levels of force to be produced. Previous research has suggested that the harder the task is, the more force is required to perform that 31 task, thus the angular velocity of that motion occurs at a slower rate (11,63,70). This is important because if slower angular velocities require higher percentage of maximal voluntary contractions, then assessing at slower angular velocity would allow ability to see the decline in the ability to perform tasks that require higher percentage of maximal voluntary contraction.
In the current study, isometric knee strength was also significantly associated with measures of physical function. This is in agreement with Sowers et al. (4) who found that isometric knee strength was associated with gait time and the time it takes to ascend and descend stairs. Additionally, Landers et al. (59), found that measurements of isometric strength of the lower body were significantly associated with standing from a chair. While these function measures differ from those in the present study, it is important to note that isometric strength is indicative of functional ability. However, in our study the strength of the association between isometric strength and physical function was lower that between isokinetic strength and physical function. Further, during activities of daily living, individuals are less likely to perform isometric contractions, but typically move through a range of motion, suggesting that isokinetic strength measures may be more appropriate.
Additionally, the current study found that MQ-KN60 is most highly related to a lower body physical function composite score, as well as individual physical function tasks including TRANSFER, 30-CS, and 6MWT, compared to other measures of muscle quality.
Similar to the present findings, Ward-Ritacco et al. (16), found that MQ-KN60 was significantly associated with 30-CSand 6MWT performance, indicating that higher MQ is associated with better functional ability. Ward-Ritacco et al. (16) also found that MQ-KN60 was significantly associated with UP-GO performance, while the present study did 32 not. In the study by Ward-Ritacco et al. (16) all study participants were postmenopausal, indicating that this assessment may not be appropriate for pre and peri menopausal samples of middle-aged women. Additionally, Ward-Ritacco et al. (16) only assessed MQ-KN60, therefore present study provides a more comprehensive assessment of the associations between muscle quality calculated with isometric strength and isokinetic strength at varying speeds. The present study found that MQ-KN180 was more highly associated with UP-GO when compared to MQ-KN60. UP-GO assesses both muscular power and balance (36). A key component of the development of muscular power is the activation time of the contraction (11,71). Using the force-velocity relationship, peak power occurs at a higher percentage of maximum velocity (11,70), demonstrating that measurements using higher velocity would be more highly associated with measures of muscular power than muscular strength. Because the measurement of muscular strength at 180 degrees per second required a shorter duration of muscle activation, it makes sense that this measurement would be more highly related to muscular power compared to measurement of muscle strength at 60 degrees per second.
The results from this study also suggest that when resistance training, designing a program for both increase muscular strength as well as endurance is important as both measures of muscular strength were associated with physical functions tasks that assess these components. Additionally, multi-joint exercises should be focused on as most activities of daily living requires this.
The present study supports support the use of the MQ-KN60 and MQ-KN180 when examining determinants of physical functional ability that address muscular endurance, strength and power. The reason why MQ-KN60 is thought to be more highly related to 33 tasks that assess endurance and strength is because the measurement of isokinetic muscular strength at 60 degrees per second has a longer duration to produce the max contraction causing it to be more strongly associated with endurance and measures of muscular strength instead of tests that assess muscular power. These results also provide insight into intervention design, as resistance training programs should be designed to improve isokinetic strength at 60 degrees per second and at 180 degrees per second, while also focusing on improving lean mass. Improving muscle quality in these domains should improve functional performance across the spectrum.
One of the strengths of the current investigation is the use of objective measures when assessing physical activity (15,27,72). While both subjective and objective methods have been validated, participants tend to overestimate their levels of physical activity when using self-report methods (73). The measurement of physical activity in this current study is also a strength because physical activity level has been reported to affect physical function performance (6,16). As all analysis of the association between muscular strength, muscle quality and physical functional ability were controlled for physical activity levels, the results found in this study are representative of a more accurate measurement of the association between muscular strength, muscle quality and physical function in middleaged women. An additional strength related to measuring physical activity is the inclusion of both steps per day and the amount of moderate to vigorous physical activity achieved by participants. Our results indicate that average steps per day are just slightly more highly related to a lower body physical function composite score. This supports the use of simple step counters if more expensive technology such as, accelerometry is unavailable or not feasible, when designing interventions or crafting behavior change messaging to help individuals improve their physical functional ability.
No study is ever without limitations. The current study's population is not diverse, where a majority of the study population were Caucasian, and were relatively active with a mean average steps per day of 8,176.55. Compared to current large studies of physical activity in adults, it is suggested that the average adults walks on average 6,927 steps per day (74). Therefore, the results of this study can only truly be applied to the current population and not generalized for all middle-aged women. The current study also did not include a measurement of muscular power, which has been shown to have a higher age related rate of decline compared to muscle mass and muscular strength (9,11), and has previously been more highly related to physical functional ability compared to muscular strength (11,17,55). Therefore, it is important to consider this in future studies examining the determinants of physical function in middle-aged women. Thirdly, while DXA scans are a highly validated tool for measuring body composition, DXA technology does not measure intramuscular fat mass, which may be a contributing factor to decreased physical functional ability (52,53). Thus, studies also assessing body composition using either computed tomography or MRI, when feasible and warranted, may be beneficial (11,75,76). The last limitation of this study is that physical functional ability was not examined by menopausal status groups. Previous research has assessed the association between menopausal status and physical functional ability (25,33,77), and have found some differences based on menopausal group. Therefore, examining the data in this manner would add to the existing body of literature.    The purpose of this research study is to assess markers of physical and mental health and quality of life among middle-aged women. We are asking eligible participants to come to the Department of Kinesiology at the University of Rhode Island for two measurement visits that will be completed 7-10 days apart. If you participate in the study, we will measure your body composition, ask you questions about yourself, such as questions about your body perceptions, personality, and well-being, assess your physical function, muscular strength, and assess your levels of physical activity and levels of stress. We will also ask you to wear a physical activity monitor clipped to your waist during all waking hours for 7 days, provide us with saliva samples and answer some questionnaires at home during the time between your visits.
Do you think you might be interested in participating in this study? oYes oNo Skip To: Q2 If Thank you for your interest in our research study. The purpose of this research study is to asses... = Yes Skip To: End of Survey If Thank you for your interest in our research study. The purpose of this research study is to asses... = No Q2 Before enrolling you in our study, we need to ask you some questions to determine if you are eligible. Please answer the following questions about yourself and your health history. This should only take about 15 minutes of your time. Some of these questions pertain to sensitive topics and therefore there is a possibility that some of these questions may make you uncomfortable. If so, you can skip any questions you do not choose to answer.
All information that you share in this screening process, including your name and any other information that can possibly identify you, will be strictly confidential and will be kept under lock and key. If after completion of this screening process it is determined that you are not eligible for the study then, if you grant us permission, we will keep your screening information in a password protected computer file in the event our eligibility criteria change and you then become eligible for participation in the current study.
If you do not want us to keep your information on file, we will record the reason for your ineligibility, without any of your identifying information and then destroy your screening information. If you are eligible for the study and you decide to participate, your information will be coded with an identifying number and we will contact you to schedule your first visit. Remember, your participation is voluntary; you can refuse to answer any questions or stop the screening process at any time without penalty or loss of benefits to which you are otherwise entitled.