Physical activity and osteoarthritis: a consensus study to harmonise self-reporting methods of physical activity across international cohorts.

Physical activity (PA) is increasingly recognised as an important factor within studies of osteoarthritis (OA). However, subjective methods used to assess PA are highly variable and have not been developed for use within studies of OA, which creates difficulties when comparing and interpreting PA data in OA research. The aim of this study was, therefore, to gain expert agreement on the appropriate methods to harmonise PA data among existing population cohorts to enable the investigation of the association of PA and OA. The definition of PA in an OA context and methods of harmonization were established via an international expert consensus meeting and modified Delphi exercise using a geographically diverse committee selected on the basis of individual expertise in physical activity, exercise medicine, and OA. Agreement was met for all aims of study: (1) The use of Metabolic Equivalent of Task (MET) minutes per week (MET-min/week) as a method for harmonising PA variables among cohorts; (2) The determination of methods for treating missing components of MET-min/week calculation; a value will be produced from comparable activities within a representative cohort; (3) Exclusion of the domain of occupation from total MET-min/week; (4) The need for a specific measure of joint loading of an activity in addition to intensity and time, in studies of diseases, such as OA. This study has developed a systematic method to classify and harmonise PA in existing OA cohorts. It also provides minimum requirements for future studies intending to include subjective PA measures.

Testing the differential effects of acceptance and attention-based psychological interventions on intrusive thoughts and worry.

BACKGROUND: Worry is a key component of anxiety and may be an effective target for therapeutic intervention. We compared two psychological processes (attention and acceptance) on the frequency of intrusive worrying thoughts in an experimental worry task. METHOD: 77 participants were randomised across three groups and completed either a 10 min attention or acceptance-based psychological exercise, or progressive muscle relaxation control. We subsequently measured anxiety, and the content and frequency of intrusive thoughts before and after a 'worry induction task'. RESULTS: Groups did not differ in baseline worry, anxiety or thought intrusions. Both attention and acceptance-based groups experienced fewer negative thought intrusions (post-worry) compared to the relaxation control group. The acceptance exercise had the largest effect, preventing 'worry induction'. Increases in negative intrusive thoughts predicted subjective anxiety. DISCUSSION: We provide evidence that acceptance and attention psychological exercises may reduce anxiety by reducing the negative thought intrusions that characterise worry.

Using an Analysis of Behavior Change to Inform Effective Digital Intervention Design: How Did the PRIMIT Website Change Hand Hygiene Behavior Across 8993 Users?

BACKGROUND: In designing digital interventions for healthcare, it is important to understand not just whether interventions work but also how and for whom-including whether individual intervention components have different effects, whether a certain usage threshold is required to change behavior in each intervention and whether usage differs across population subgroups. PURPOSE: We investigated these questions using data from a large trial of the digital PRimary care trial of a website based Infection control intervention to Modify Influenza-like illness and respiratory tract infection Transmission) (PRIMIT) intervention, which aimed to reduce respiratory tract infections (RTIs) by increasing hand hygiene behavior. METHOD: Baseline and follow-up questionnaires measured behaviors, intentions and attitudes in hand hygiene. In conjunction with objective measures of usage of the four PRIMIT sessions, we analysed these observational data to examine mechanisms of behavior change in 8993 intervention users. RESULTS: We found that the PRIMIT intervention changed behavior, intentions and attitudes, and this change was associated with reduced RTIs. The largest hand hygiene change occurred after the first session, with incrementally smaller changes after each subsequent session, suggesting that engagement with the core behavior change techniques included in the first session was necessary and sufficient for behavior change. The intervention was equally effective for men and women, older and younger people and was particularly effective for those with lower levels of education. CONCLUSIONS: Our well-powered analysis has implications for intervention development. We were able to determine a 'minimum threshold' of intervention engagement that is required for hand hygiene change, and we discuss the potential implications this (and other analyses of this type) may have for further intervention development. We also discuss the application of similar analyses to other interventions.

Evaluation of the MyWellness Key accelerometer.

OBJECTIVE: to examine the concurrent validity of the Technogym MyWellness Key accelerometer against objective and subjective physical activity (PA) measures. DESIGN: randomised, cross-sectional design with two phases. The laboratory phase compared the MyWellness Key with the ActiGraph GT1M and the Yamax SW200 Digiwalker pedometer during graded treadmill walking, increasing speed each minute. The free-living phase compared the MyWellness Key with the ActiGraph, Digiwalker, Bouchard Activity cord (BAR) and Global Physical Activity Questionnaire (GPAQ) for seven continuous days. Data were analysed using Spearman rank-order correlation coefficients for all comparisons. SETTING: laboratory and free-living phases. PARTICIPANTS: sixteen participants randomly stratified from 41 eligible respondents by sex (n=8 men; n=8 women) and PA levels (n=4 low, n=8 middle and n=4 high active). RESULTS: there was a strong association between the MyWellness Key and the ActiGraph accelerometer during controlled graded treadmill walking (r=0.91, p<0.01) and in free-living settings (r=0.73-0.76 for light to vigorous PA, respectively, p<0.01). No associations were observed between the MyWellness Key and the BAR and GPAQ (p>0.05). CONCLUSIONS: the MyWellness Key has a high concurrent validity with the ActiGraph accelerometer to detect PA in both controlled laboratory and free-living settings.

Exercise prescription for the overweight and the obese: how to quantify and yet keep it simple.

An activity point system (APS) is presented that assists healthcare providers and health professionals with a way to prescribe exercise in a semiquantitative manner and to motivate their patients to begin an exercise programme. Activity points are specific to one's body weight, body mass index and activity intensity for 10-minute bouts of activity performed. With a goal of accumulating 100-300 activity points per week, the APS provides a simple yet quantitatively accurate way to prescribe exercise for overweight and obese adults.

How do I measure physical activity in my patients? Questionnaires and objective methods.

How do healthcare providers know if their patients are getting enough physical activity to promote good health and to reduce their risks of chronic diseases and injury? The first step is to identify the patient's current level of physical activity using questionnaires and/or motion sensors. Questionnaires assess activity levels by having patients answer a set of questions about the types and amounts of activity performed at some time in the past. Motion sensors assess physical activity by patients wearing a small monitoring device that records their body movement as it occurs. If a provider is interested in determining a patient's caloric energy expenditure, he/she can apply statistical regression models to the questionnaire and motion sensor data to estimate kilocalories. If more precise measures of energy expenditure are desired, a provider can use the isotopic doubly labelled water method to estimate kilocalories; however, this method is costly and is impractical in non-research clinical settings.

BMI-referenced cut points for pedometer-determined steps per day in adults.

BACKGROUND: The goal of this study was to establish preliminary criterion-referenced cut points for adult pedometer-determined physical activity (PA) related to weight status defined by body mass index (BMI). METHODS: Researchers contributed directly measured BMI and pedometer data that had been collected (1) using a Yamax-manufactured pedometer, (2) for a minimum of 3 days, (3) on ostensibly healthy adults. The contrasting groups method was used to identify age- and gender-specific cut points for steps/d related to BMI cut points for normal weight and overweight/obesity (defined as BMI <25 and >or=25 kg/m2, respectively). RESULTS: Data included 3127 individuals age 18 to 94 years (976 men, age = 46.8 +/- 15.4 years, BMI = 27.3 +/- 4.9; 2151 women, age = 47.4 +/- 14.9 years, BMI = 27.6 +/- 6.4; all gender differences NS). Best estimated cut points for normal versus overweight/obesity ranged from 11,000 to 12,000 steps/d for men and 8000 to 12,000 steps/d for women (consistently higher for younger age groups). CONCLUSIONS: These steps/d cut points can be used to identify individuals at risk, or the proportion of adults achieving or falling short of set cut points can be reported and compared between populations. Cut points can also be used to set intervention goals, and they can be referred to when evaluating program impact, as well as environmental and policy changes.

Health-related quality of life, BMI and physical activity among US adults (>/=18 years): National Physical Activity and Weight Loss Survey, 2002.

OBJECTIVE: To examine the association between health-related quality of life (HRQOL) and physical activity (PA). METHODS: Cross-sectional data were obtained via a national telephone survey from 9173 respondents (30.9% response rate; 51.4% cooperation rate). Four indicators of HRQOL were measured: self-rated health, physically unhealthy days, mentally unhealthy days and activity limitation days. Prevalence estimates were calculated by body mass index (BMI) category and PA level. Logistic regression evaluated BMI as an effect modifier of the relationship between HRQOL and PA. RESULTS: Inactive adults reported more fair to poor HRQOL than active adults, regardless of BMI category (P<0.001). BMI did not modify the association between PA and any of the four HRQOL indicators. CONCLUSION: Prevalence of low HRQOL is inversely related to PA participation, and the relationship is not altered by BMI status. Regardless of their weight status, adults should be encouraged to engage in PA.

Cross-sectional comparison of physical activity and inactivity patterns in Chinese and Filipino youth.

BACKGROUND: To compare and contrast youth physical activity (PA) and inactivity patterns in two developing Asian countries: the Philippines and China. METHODS: Comparative analysis of 1997-1999 Cebu Longitudinal Health and Nutrition Survey and the 1997 China Health and Nutrition Survey, large-scale surveys that included questions on type, frequency and duration of: commuting mode to school, sports/exercise in and outside of school, select sedentary activities and chores. RESULTS: Filipino data included 760 males and 872 females aged 14-16 years. The comparable Chinese sample consisted of 202 males and 197 females. Active commuting is proportionately high in both countries (70-71% in the Philippines vs. 77-90% in China), although commuting by bicycling is rare in the Philippines (<1%) vs. China ( approximately 35%). Patterns of school sport/exercise participation differ between countries by gender; more Filipino males report school sport/exercise than females (63 vs. 49%) vs. China, where more females participate than males (75 vs. 69%). Sport/exercise outside of school is proportionately low (6-12%) for youth from both countries with a single exception: 74% of Filipino males participate in extra-curricular sport/exercise. Although a higher percentage of Filipino youth report watching television >4 h/day (<10%) vs. Chinese youth (<1%), both are lower than comparable US reports. CONCLUSION: In the Philippines, continued modernization augurs a decrease in local primary PA sources (chores and active commuting). In China, where youth already are not expected to perform chores, shifts to more passive commuting modes (i.e. increased motorized transportation) are anticipated.

Small bowel hemangioma diagnosed with laparoscopy: Report of two pediatric cases.

Hemangiomas of the small bowel are rare tumors that often present with gastrointestinal bleeding. Diagnosis can be difficult and exploratory laparotomy has often proved to be the only method with which to determine the presence and location of these tumors. We report two cases of small bowel hemangioma in children aged 10 and 7 years, in which the diagnosis was made by laparoscopy. Laparoscopy identifies the affected segment of bowel and allows delivery to a minimally extended umbilical port site. The avoidance of an open laparotomy helps to reduce post-operative analgesic requirement and achieves an early return of bowel function.

How many days of pedometer monitoring predict weekly physical activity in adults?

BACKGROUND: The study purpose was to establish the number (and type) of days needed to estimate mean pedometer-determined steps/day in a field setting. METHODS: Seven days of data were collected from 90 participants (33 males, age = 49.1 +/- 16.2 years, BMI = 27.2 +/- 4.1 kg/m(2); 57 females, age = 44.8 +/- 16.9 years, BMI = 27.0 +/- 5.9 kg/m(2)). Mean steps/day were computed for all 7 days (the criterion), each single day, and combinations of days. Analyses included repeated measures ANOVA, intra-class correlations (ICC), and regression. RESULTS: There was a significant difference (P < 0.001) between days. The difference was limited to Sunday and accounted for 5% of the variance. ICC analyses indicated a minimum of 3 days is necessary to achieve a reliability of 0.80. The adjusted R(2) was 0.79 for a single day (specifically Wednesday), 0.89 for 2 days (Wednesday, Thursday), and 0.94 for 3 days (Wednesday, Thursday, Friday). Sunday was the last day to enter the model. CONCLUSIONS: Although there is a statistical difference between days, there is little practical difference, and the primary distinction appears limited to Sunday. Although a single day of collection is not acceptable, any 3 days can provide a sufficient estimate.

Physical activity and inactivity in Chinese school-aged youth: the China Health and Nutrition Survey.

OBJECTIVE: To describe physical activity (PA) and inactivity levels and patterns in Chinese school children (aged 6-18 y). DESIGN: PA and inactivity were assessed in a youth cohort enrolled in the China Health and Nutrition Survey (CHNS) in 1997. SUBJECTS: A total of 1423 males (11.5+/-3.2 y) and 1252 females (11.5+/-3.3 y). MEASUREMENTS: PA and inactivity were assessed by self-reported usual activity (questionnaire). Children under 10 y were assisted by parents. RESULTS: Approximately 84% of Chinese youth actively commute to school for a median of 100-150 min/week. A total of 72% engage in in-school moderate/vigorous (MOD/VIG) PA for a median of 90-110 min/week. Relatively few children ( approximately 8%) participate in any MOD/VIG PA outside of school. A total of 72% engage in study-related activities outside of school for a median of 420 min/week. Only 8% of Chinese school children, regardless of gender, watch television > or =2 h/day; less than 1% watch > or =4 h/day. Chores related to housework are not a part of life for Chinese school children; fewer than 20% performed these tasks. CONCLUSION: Chinese youth are unique compared to those in other developing countries because they do not perform household chores. Instead, they are under pressure to achieve scholastically. Participation in MOD/VIG PA outside of school is almost nonexistent. Current television watching habits are relatively low compared to developed countries and walking/biking is a common form of commuting. The descriptive analysis herein represents the foundation upon which future longitudinal studies of PA in this population will be based.

Physical activity in Filipino youth: the Cebu Longitudinal Health and Nutrition Survey.

OBJECTIVE: To describe physical activity (PA) and inactivity levels of Filipino youth aged 14-16 y. DESIGN: PA type and patterns were assessed in an adolescent cohort enrolled in the Cebu Longitudinal Health and Nutrition Survey. SUBJECTS: A total of 1053 males (aged 15.6+/-0.5 y; body mass index (BMI)=18.6+/-2.6 kg/m(2)) and 990 females (aged 14.6+/-0.5 y; BMI=18.8+/-2.4 kg/m(2)). MEASUREMENTS: PA was assessed by (1) self-reported usual PA (questionnaire); (2) 24-h objective monitoring (Caltrac accelerometer); and (3) 24 h recalls of PA during the objectively monitored time frame. RESULTS: As measured by Caltrac, males expended 378.0+/-164.5 kcal and females 271.0+/-105.4 kcal. The measurement approaches employed agreed in expected ways, given the limitations of each. Together the approaches used indicated that the primary sources of PA for this population are chores and active commuting. In all, 40% of the sample walked to school, less than 1% rode a bicycle, 22% rode in/on motorized transport, and 37% used some combination of walking and motorized transport. Further, gender differences exist for type, frequency, and duration of physical activities performed by Filipino youth. Specifically, females report engaging in few leisure-time physical activities and more household chores. In total, 48% of Filipino youth report watching > or =2 h/day of television; relatively few youth (7%) report watching >4 h/day at this time. An 18% of males report no vigorous activities compared to 87% of females. CONCLUSION: Clear gender differences in PA patterns and levels exist in Filipino adolescents. Nonsport/exercise type activities (eg chores and active commuting) currently provide a large proportion of daily activity for both males and females, however. It is anticipated that as modernization and technological advancement continue in this developing country, these primary sources of PA will decrease.

The association between joint stress from physical activity and self-reported osteoarthritis: an analysis of the Cooper Clinic data.

OBJECTIVE: The purpose was to evaluate the association between estimated joint stress from physical activity (PA) and hip/knee osteoarthritis (OA). DESIGN: A nested case-control study was performed using data from the Aerobics Center Longitudinal Study. Participants without self-reported OA at baseline who attended the clinic between 1974 and 1993 and returned a follow-up questionnaire in 1990 or 1995 were eligible. Cases were those who reported a physician diagnosis of OA of the knee and/or hip at follow-up (N = 415). A random sample of persons in the remaining cohort were classified as controls (N = 1995). PA was measured at baseline by self-report and subjects were classified as 'moderate/high' or 'low' joint stress by PA type. Those reporting no PA were classified as sedentary with 'no' joint stress (the reference group). Men and women were analyzed separately. Stratified analysis and multiple logistic regression were used to assess the relationship between hip/knee OA and joint stress as predicted by PA. RESULTS: After adjustment for age, body mass index, years of follow-up, and history of hip/knee joint injury, among men, there was no association between hip/knee OA and low joint stress while moderate/high joint stress was associated with reduced risk of hip/knee OA (adjusted odds ratio (OR) = 0.62, 95% confidence interval (CI) = 0.43-0.89). Among women, both levels of joint stress were associated with reduced risk of hip/knee OA (OR = 0.58, 95% CI = 0.34-0.99 for low and OR=0.24, 95% CI = 0.11-0.52 for moderate/high). CONCLUSIONS: PA may reduce the risk of hip/knee OA, especially among women. Further research should assess the combined effects of frequency, intensity, duration and joint stress level of PA on incidence of hip/knee OA.

Omission of active commuting to school and the prevalence of children's health-related physical activity levels: the Russian Longitudinal Monitoring Study.

BACKGROUND: Active commuting to school by walking or bicycle is a potential source of continuous moderate activity for children that has been largely ignored in surveys of physical activity. The purpose of this study was to evaluate the analytical impact of omitting active commuting to school (walking or bicycling) on conclusions about children's physical activity levels. METHODS: The Russian Longitudinal Monitoring Study (RLMS) is the first nationally representative household survey in the Russian Federation. More than 6400 households from all regions of Russia were surveyed eight times between 1992 and 1998. Analysis was conducted using physical activity data (school physical education classes, out-of-school active pursuits and active commuting to school) obtained by parent-proxy on 1094 (572 boys, 522 girls) school-aged Russian children (mean age 10.2 +/- 1.9 years) participating in the November 1998 round of the RLMS. Data were examined according to prevalence of achievement of health-related physical activity guidelines, active commuting to school behaviours included then omitted. RESULTS: Omitting active commuting to school resulted in a statistically significant decrease in the prevalence of achievement of health-related guidelines from 12% to 20%, similar for both genders. Likewise, the prevalence of sedentarism (defined as not meeting any of the guidelines) was increased by 17-22%. CONCLUSIONS: The present findings suggest that, in order to avoid misclassification bias of children's physical activity levels, it is necessary to include questions about mode of commuting to school. The findings also carry practice implications: the commonplace need to get to and from school may be a missed opportunity for children's health-related physical activity in motorized societies.

Limitations on the use of a single screening question to measure sedentary behavior.

OBJECTIVES: This study explored the limitations of identifying sedentary individuals via an existing screening question in a state-based surveillance system. METHODS: A national sample (n = 7529) of adults, selected by random-digit dialing between November 1999 and May 2000, responded about participation in leisure-time physical activity. RESULTS: Of those who initially reported no leisure-time physical activity (25%), 85% were engaging in at least some activity, and 20% were engaging in enough moderate- or vigorous-intensity activity to meet health-related recommendations. CONCLUSIONS: Public health programs that use only 1 screening question to identify sedentary behavior may not be able to target physical activity messages effectively, especially if physical activity is defined to include a broad range of activities beyond sports.

The relationship between pedometer-determined ambulatory activity and body composition variables.

OBJECTIVE: To examine the relationship between pedometer-determined ambulatory activity (steps/day) and body composition variables body mass index (BMI) and percentage body fat). DESIGN: : Secondary analysis of a cross-sectional objective activity monitoring study for up to 21 consecutive days. SUBJECTS: A total of 109 apparently healthy adults (eight African American males, 23 African-American females, 33 Caucasian males, 45 Caucasian females), age 44.9+/-15.8 y, BMI=26.9+/-5.1 kg/m2. MEASUREMENTS: Pedometer-assessed ambulatory activity (steps/day), height and weight, and percentage body fat by bioelectrical impedance. RESULTS: Analyzed as both a continuous and a categorical variable (determined using 25th and 75th percentiles for distribution for steps/day), ambulatory activity was consistently related to body composition variables. Steps/day was inversely correlated with BMI and percentage body fat (r=-0.30, and r=-0.27, respectively, both P<0.01). The consistency of the relationship was also evident when examined using accepted BMI cut-off points for normal-weight, overweight, and obese categories. CONCLUSIONS: Individuals in this small sample with values greater than approximately 9000 steps/day are more frequently classified as normal weight for height. Individuals with values less than approximately 5000 steps/day are more frequently classified as obese. These findings require further corroborative investigation but provide preliminary cutoff points for identifying individuals at risk who may benefit from appropriate physical activity intervention.

Prevalence of physical activity among South Carolina adults.

Participating in regular PA is associated with many health benefits. Overall, the prevalence of inactivity in South Carolina (33 percent) is among the highest in the Southeast and in the US as a nation. While few gender differences exist between the proportion of adults who report participation in sufficient PA (females 21 percent and males 23 percent), racial and age differences are apparent with ethnic minorities and older adults as the least active. The most popular PA among all adults is walking. Physicians can play a key role, through counseling, to help increase the prevalence of regular PA among those who are currently obtaining insufficient amounts of activity to derive optimal health benefits.

Racial/ethnic health disparities in South Carolina and the role of rural locality and educational attainment.

BACKGROUND: The prevalence of selected health indicators were compared among the Catawba Indians, African Americans, and whites in South Carolina, considering the possible role of rural locality and education. METHODS: Catawba members were respondents of a 1998 survey (N = 808). Other South Carolina residents were respondents of the 1995-1997 Behavioral Risk Factor Survey (4,150 whites and 1,413 African Americans). Prevalence of cardiovascular disease, diabetes, hypertension, overweight, poor health, smoking, physical inactivity, and poor diet were compared among the racial/ethnic groups. Logistic regression analyses were conducted within strata of urban/rural locality and education to determine whether these factors were associated with the adverse health indicators. RESULTS: Both Catawba and African Americans had higher prevalence of diabetes, hypertension, overweight, poor health, physical inactivity, and poor diet than whites. In addition, prevalence of diabetes, poor health, smoking, and poor diet were higher among the Catawba than among African Americans. Restricting the analyses to comparisons within urban/rural locality had little effect, whereas restricting the analyses to comparisons by education level eliminated many of the disparities among those with low education. CONCLUSIONS: Prevalence of chronic disease and adverse health behavior are higher among the Catawba than among other residents of South Carolina, especially compared with white residents.