Activity In Epidemiological Studies Research Articles

Validity and Relative Validity of Alternative Methods of Assessing Physical Activity in Epidemiologic Studies: Findings From the Men's Lifestyle Validation Study.

In the Men's Lifestyle Validation Study (2011-2013), we examined the validity and relative validity of a physical activity questionnaire (PAQ), a Web-based 24-hour recall (Activities Completed Over Time in 24 Hours (ACT24)), and an accelerometer by multiple comparison methods. Over the course of 1 year, 609 men completed 2 PAQs, two 7-day accelerometer measurements, at least 1 doubly labeled water (DLW) physical activity level (PAL) measurement (n=100 with repeat measurements), and 4 ACT24s; they also measured their resting pulse rate. A subset (n=197) underwent dual-energy x-ray absorptiometry (n=99 with repeated measurements). The method of triads was used to estimate correlations with true activity using DLW PAL, accelerometry, and the PAQ or ACT24 as alternative comparison measures. Estimated correlations of the PAQ with true activity were 0.60 (95% confidence interval (95% CI): 0.52, 0.68) for total activity, 0.69 (95% CI: 0.61, 0.79) for moderate-to-vigorous physical activity (MVPA), and 0.76 (95% CI: 0.62, 0.93) for vigorous activity. Corresponding correlations for total activity were 0.53 (95% CI: 0.45, 0.63) for the average of 4 ACT24s and 0.68 (95% CI: 0.61, 0.75) for accelerometry. Total activity and MVPA measured by PAQ, ACT24, and accelerometry were all significantly correlated with body fat percentage and resting pulse rate, which are physiological indicators of physical activity. Using a combination of comparison methods, we found the PAQ and accelerometry to have moderate validity for assessing physical activity, especially MVPA, in epidemiologic studies.

Reproducibility, Validity, and Relative Validity of Self-Report Methods for Assessing Physical Activity in Epidemiologic Studies: Findings From the Women’s Lifestyle Validation Study

Among 683 participants in the Women's Lifestyle Validation Study (2010-2012), we evaluated the performance of a self-administered physical activity questionnaire (PAQ) and Web-based 24-hour recalls (Activities Completed Over Time in 24 Hours (ACT24)) using multiple comparison methods. Two PAQs, 4 ACT24s, two 7-day accelerometer measurements, 1 doubly labeled water (DLW) physical activity level (PAL) measure (repeated; n=90), and 4 resting pulse rate measurements were collected over 15 months. The deattenuated correlation between the PAQ and DLW PAL was 0.41 (95% confidence interval (CI): 0.33, 0.49) for total physical activity (PA) and 0.40 (95% CI: 0.31, 0.48) for moderate-to-vigorous PA (MVPA). These correlations were similar when using accelerometry as the comparison method. Single and averaged ACT24 measurements had lower correlations with DLW and accelerometry as comparison methods. The PAQ showed inverse correlations with DLW body fat percentage and resting pulse rate. Using the method of triads, the estimated correlation of the PAQ with true total PA was 0.54 (95% CI: 0.47, 0.62) and that with true MVPA was 0.60 (95% CI: 0.52, 0.69). For averaged ACT24, the estimated correlations were 0.50 (95% CI: 0.43, 0.59) for total PA and 0.47 (95% CI: 0.39, 0.58) for MVPA, and for averaged accelerometry, these estimated correlations were 0.72 (95% CI: 0.64, 0.81) and 0.62 (95% CI: 0.53, 0.71), respectively. The PAQ provided reasonable validity for total PA and MVPA.

Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults

Increasing evidence shows that physical activity is associated with reduced risk for depression, pointing to a potential modifiable target for prevention. However, the causality and direction of this association are not clear; physical activity may protect against depression, and/or depression may result in decreased physical activity. To examine bidirectional relationships between physical activity and depression using a genetically informed method for assessing potential causal inference. This 2-sample mendelian randomization (MR) used independent top genetic variants associated with 2 physical activity phenotypes-self-reported (n = 377 234) and objective accelerometer-based (n = 91 084)-and with major depressive disorder (MDD) (n = 143 265) as genetic instruments from the largest available, nonoverlapping genome-wide association studies (GWAS). GWAS were previously conducted in diverse observational cohorts, including the UK Biobank (for physical activity) and participating studies in the Psychiatric Genomics Consortium (for MDD) among adults of European ancestry. Mendelian randomization estimates from each genetic instrument were combined using inverse variance weighted meta-analysis, with alternate methods (eg, weighted median, MR Egger, MR-Pleiotropy Residual Sum and Outlier [PRESSO]) and multiple sensitivity analyses to assess horizontal pleiotropy and remove outliers. Data were analyzed from May 10 through July 31, 2018. MDD and physical activity. GWAS summary data were available for a combined sample size of 611 583 adult participants. Mendelian randomization evidence suggested a protective relationship between accelerometer-based activity and MDD (odds ratio [OR], 0.74 for MDD per 1-SD increase in mean acceleration; 95% CI, 0.59-0.92; P = .006). In contrast, there was no statistically significant relationship between MDD and accelerometer-based activity (β = -0.08 in mean acceleration per MDD vs control status; 95% CI, -0.47 to 0.32; P = .70). Furthermore, there was no significant relationship between self-reported activity and MDD (OR, 1.28 for MDD per 1-SD increase in metabolic-equivalent minutes of reported moderate-to-vigorous activity; 95% CI, 0.57-3.37; P = .48), or between MDD and self-reported activity (β = 0.02 per MDD in standardized metabolic-equivalent minutes of reported moderate-to-vigorous activity per MDD vs control status; 95% CI, -0.008 to 0.05; P = .15). Using genetic instruments identified from large-scale GWAS, robust evidence supports a protective relationship between objectively assessed-but not self-reported-physical activity and the risk for MDD. Findings point to the importance of objective measurement of physical activity in epidemiologic studies of mental health and support the hypothesis that enhancing physical activity may be an effective prevention strategy for depression.

Adaptation and reproducibility of a questionnaire to assess physical activity in epidemiological studies among Yaqui Indians from Sonora, Mexico

Introduction: Due to the benefits of physical activity (PA) for health and the associated risk of physical inactivity with obesity and non-communicable diseases, the evaluation of PA is of great interest in public health. Objective: Was adapt and evaluate the reproducibility of a questionnaire to assess PA in epidemiological studies among Yaqui Indians from Sonora, México. Methods: The participants were 100 Indians from the 9 Yaquis communities, including men and women aged 20 or older. The adaptation phase of the PA questionnaire (PAQ) was done by interviewing 40 Yaquis about their activities related to leisure-time, occupation and transportation. For the reproducibility analysis, the PAQs applied by duplication to 60 adults were evaluated by the Spearman Correlation Coefficient (ρ) and Intraclass Correlation Coefficient (ICC). The level of agreement was evaluated by the Bland-Altman plot. Results: Eighteen leisure time activities, 34 occupational activities, and 5 transportation activities were included in the PAQ. Very strong correlations were found for total leisure-time and occupational activities (ρ=0.92 and ρ=0.88, respectively; p<0.0001), and sedentary behaviors (ρ=0.94; p<0.0001) for the previous 12 months. The Bland-Altman plots indicated high agreement between PAQs. Conclusion: The adapted PAQ had high reproducibility for measuring PA in the Yaqui Indian population.Key Words: Ethnic groups; México; physical activity questionnaire. RESUMENIntroducción: Debido a los beneficios de la actividad física (AF) en la salud y la asociación de la inactividad física con la obesidad y las enfermedades no transmisibles, evaluar la AF es de gran relevancia para la salud pública. Objetivo: Adaptar y evaluar la reproducibilidad de un cuestionario para medir la AF en estudios epidemiológicos de adultos Yaquis de Sonora, México. Metodología: Se incluyeron 100 Yaquis (hombres y mujeres) de 9 localidades con edad igual o mayor a 20 años. Para la adaptación del cuestionario de AF (CAF) se entrevistaron a 40 participantes sobre sus actividades recreativas, ocupacionales y de transporte. Para la reproducibilidad, los CAFs aplicados por duplicado a 60 Yaquis fueron evaluados por Correlación de Spearman (ρ) y Correlación Intraclase (CI). La concordancia fue analizada por gráfico de Bland-Altman. Resultados: Dieciocho actividades de tiempo libre, 34 ocupacionales y 5 de transporte fueron incluidas en el CAF. Se encontraron correlaciones fuertes para actividades del tiempo libre y ocupacionales así como hábitos sedentarios (ρ=0.92, ρ=0.88, ρ=0.94; respectivamente; p<0.0001) para los 12 meses previos. Los gráficos de Bland-Altman indicaron un alto nivel de concordancia entre los CAFs. Conclusión: El CAF adaptado tuvo alta reproducibilidad para medir la AF en Yaquis.Palabras Clave: Grupos étnicos; México; cuestionario de actividad física

HUBUNGAN KONSUMSI ASAM LEMAK OMEGA-3, AKTIVITAS FISIK DAN PERSEN LEMAK TUBUH DENGAN TINGKAT DISMENORE PADA REMAJA

Background: Dysmenorrhea or menstrual pain was a gynecological complaint due to an imbalance of progesterone in the blood resulting in pain. A woman with dysmenorrhea should consume food rich in omega-3 fatty acids such as fish oil, fish (salmon, tuna, mackerel, herring), soybeans and fruits. Low fish consumption was related with severity of dysmenorrhea. In addition, physical activity and percent body fat were also associated with severity of dysmenorrhea.Objective : To determine the correlation between consumption of omega-3 fatty acids, physical activity and percent body fat to the classification of dysmenorrhea in adolescents.Methods : Cross sectional study of 90 adolescentsselected by purposive sampling. This research was conducted in SMA N 15 and SMA N 9 Semarang. Menstrual history was measured by direct interviews and level of dysmenorrhea was measured using Numerical Rating Scale Questionnaire. Omega-3 fatty acids were measured using Food Frequency Questionnaire (FFQ) and analyzed using a nutritional software program. Physical activity was measured using A short questionnaire for the measurement of habitual physical activity in epidemiological studies. Percent body fat was measured using Bioelectrical Impedance Analysis (BIA). Data were analyzed by Independent T test/Mann Whitney. Result : There were significant correlation in omega-3 fatty acid (p= 0,015), and percent body fat (p= 0,026). While in physical activity there was no significant correlation (p= 0,394).Conclusion : Consumption of omega-3 fatty acids and percent body fat were associated with the classification of dysmenorrhea.

Reliability and validity of a new physical activity questionnaire for India.

BackgroundMeasurement of physical activity in epidemiological studies requires tools which are reliable, valid and culturally relevant. We attempted to develop a physical activity questionnaire (PAQ) that would measure physical activity in various domains over a year and which would be valid for use in adults of different age groups with varying levels of activity in urban and rural settings in low and middle income countries like India. The present paper aims to assess the reliability and validity of this new PAQ- termed the Madras Diabetes Research Foundation- Physical Activity Questionnaire (MPAQ).MethodsThe MPAQ was administered by trained interviewers to 543 individuals of either gender aged 20 years and above from urban and rural areas in 10 states of India from May to August 2011, followed by a repeat administration within a month for assessing reliability. Relative validity was performed against the Global Physical Activity Questionnaire (GPAQ). Construct validity was tested by plotting time spent in sitting and moderate and vigorous physical activity (MVPA) against body-mass index (BMI) and waist circumference. Criterion validity was assessed using the triaxial accelerometer, in a separate subset of 103 individuals. Bland and Altman plots were used to assess the agreement between MPAQ and accelerometer.ResultsThe interclass correlation coefficients (ICC) for total energy expenditure and physical activity levels were 0.82 and 0.73 respectively, between baseline and 1st month. The ICC between GPAQ and the MPAQ was 0.40 overall. The construct validity of the MPAQ showed linear association between sitting and MVPA, and BMI and waist circumference independent of age and gender. The Spearman’s correlation coefficients for sedentary activity, MVPA and overall PA for MPAQ against the accelerometer were 0.48 (95%CI-0.32-0.62), 0.44 (0.27-0.59) and 0.46 (0.29-0.60) respectively. Bland and Altman plots showed good agreement between MPAQ and accelerometer for sedentary behavior and fair agreement for MVPA.ConclusionThe MPAQ is an acceptable, reproducible and valid instrument, which captures data from multiple activity domains over the period of a year from adults of both genders and varying ages in various walks of life residing in urban and rural India.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-015-0196-2) contains supplementary material, which is available to authorized users.

Combined exposure to lead, inorganic mercury and methylmercury shows deviation from additivity for cardiovascular toxicity in rats.

Environmental exposure to metal mixtures in the human population is common. Mixture risk assessments are often challenging because of a lack of suitable data on the relevant mixture. A growing number of studies show an association between lead or mercury exposure and cardiovascular effects. We investigated the cardiovascular effects of single metal exposure or co-exposure to methylmercury [MeHg(I)], inorganic mercury [Hg(II)] and lead [Pb(II)]. Male Wistar rats received four different metal mixtures for 28 days through the drinking water. The ratios of the metals were based on reference and environmental exposure values. Blood and pulse pressure, cardiac output and electrical activity of the heart were selected as end-points. While exposure to only MeHg(I) increased the systolic blood pressure and decreased cardiac output, the effects were reversed with combined exposures (antagonism). In contrast to these effects, combined exposures negatively affected the electrical activity of the heart (synergism). Thus, it appears that estimates of blood total Hg levels need to be paired with estimates of what species of mercury dominate exposure as well as whether lead co-exposure is present to link total blood Hg levels to cardiovascular effects. Based on current human exposure data and our results, there may be an increased risk of cardiac events as a result of combined exposures to Hg(II), MeHg(I) and Pb(II). This increased risk needs to be clarified by analyzing lead and Hg exposure data in relation to cardiac electrical activity in epidemiological studies.

Agreement between two cutoff points for physical activity and associated factors in young individuals

ObjectiveTo analyze the agreement between two cutoff points for physical activity (300 and 420 minutes/week) and associated factors in youth. MethodsThe study enrolled 738 adolescents of Londrina city, Paraná, Southern Brazil. The following variables were collected by a self report questionnaire: presence of moderate to vigorous physical activity, gender, age, father and mother education level, with whom the adolescent lives, number of siblings, physical activity perception, participation in Physical Education classes, facilities available to physical activity practice and sedentary behavior. Prevalence of physical activity between criterions were compared using McNemar test and the agreement was analysed by Kappa index. Multivariate analysis was performed using Poisson regression with robust variance adjustment was applied. Results: The prevalence for physical activity was significantly different: 22,3% for 300 minutes/week and 12,8% for 420 minutes/week (p<0,05), but the agreement was strong (k=0,82, p<0,001). The variables gender, father education, physical activity perception and sedentary behavior were associated to physical activity in both analyzed criteria. Participation in Physical Education class and facilities available to physical activity practice were associated to physical activity only with 300 minutes/week cutoff point. ConclusionCaution is suggested regarding cutoffs use for physical activity in epidemiological studies, considering they can result in differences in prevalence of physical activity and its associated factors.

Concordância entre dois pontos de corte para atividade física e fatores associados em jovens

ObjectiveTo analyze the agreement between two cutoff points for physical activity (300 and 420 minutes/week) and associated factors in youth. MethodsThe study enrolled 738 adolescents of Londrina city, Paraná, Southern Brazil. The following variables were collected by a self report questionnaire: presence of moderate to vigorous physical activity, gender, age, father and mother education level, with whom the adolescent lives, number of siblings, physical activity perception, participation in Physical Education classes, facilities available to physical activity practice and sedentary behavior. Prevalence of physical activity between criterions were compared using McNemar test and the agreement was analysed by Kappa index. Multivariate analysis was performed using Poisson regression with robust variance adjustment was applied. ResultsThe prevalence for physical activity was significantly different: 22,3% for 300 minutes/week and 12,8% for 420 minutes/week (p<0,05), but the agreement was strong (k=0,82, p<0,001). The variables gender, father education, physical activity perception and sedentary behavior were associated to physical activity in both analyzed criteria. Participation in Physical Education class and facilities available to physical activity practice were associated to physical activity only with 300 minutes/week cutoff point. ConclusionCaution is suggested regarding cutoffs use for physical activity in epidemiological studies, considering they can result in differences in prevalence of physical activity and its associated factors.

Assessment of physical activity in epidemiological studies: Are questionnaires obsolete in the era of accelerometry?

Assessment of physical activity in epidemiological studies: Are questionnaires obsolete in the era of accelerometry?

Evaluation of correlation between lifestyle

AbstractObjectives: Cardiovascular diseases are the leading cause of 17’000’000 worldwide deaths annually. If the current trends continue, the number of deaths will increase to 25’000’000 by the year 2020. Lifestyle contributes to many chronic diseases such as coronary heart diseas. The aim of this study was to examine the correlation between lifestyle and ischemic heart disease.Methods: This case-control study was carried out in Damavand sevvom sha’ban hospital. The sample of the study consisted of 65 cases (patients suffering from coronary artery disease) and 65 healthy controls. Data were collected by three questionnaires: General Health Questionnaire(GHQ), FFQ (Food Frequency Questionnaire) and physical activity questionnaire . These questionnaires were completed by interviewing the participants. Data were analyzed by SPSS software.Results: There was a significant correlation between Age, Marital status, Smoking, Physical activity, diet and Mental health and ischemic heart disease.Conclusion: Insufficient physical activity, high fat and low fiber diet, inappropriate mental status were risk factors and major causes of in heart ischemia incidence.Key words: Heart Ischemia, Life Style, Physical Activity, Diet, Mental Heath. REFERENCES Ahmadvand AR. Jamshidi AR. and et al (2002). [Translation of Health World Report of 2002]. Tehran: Avicenna Institute. (Persian) American Heart Association (AHA) (2001). Heart and Stroke Facts. New York: American Heart Publication.. Aminbashi M. (1999). [Prevalence of Risk Factors for Coronary Artery Disease Patients Under 50 Hospitalized in Zahedan Khatamolanbia Heart Hospital]. MS Tehsis. Zahedan Medical Sciences University in 1373-77 year. (Persian) Azizi F. (2001). (Sugar & Lipid in People of Tehran). 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Is There a Sex Difference in Accelerometer Counts During Walking in Older Adults?

Accelerometers have emerged as a useful tool for measuring free-living physical activity in epidemiological studies. Validity of activity estimates depends on the assumption that measurements are equivalent for males and females while performing activities of the same intensity. The primary purpose of this study was to compare accelerometer count values in males and females undergoing a standardized 6-minute walk test. The study population was older adults (78.6 ± 4.1 years) from the AGES-Reykjavik Study (N = 319). Participants performed a 6-minute walk test at a self-selected fast pace while wearing an ActiGraph GT3X at the hip. Vertical axis counts · s(-1) was the primary outcome. Covariates included walking speed, height, weight, BMI, waist circumference, femur length, and step length. On average, males walked 7.2% faster than females (1.31 vs. 1.22 m · s(-1), P < .001) and had 32.3% greater vertical axis counts · s(-1) (54.6 vs. 39.4 counts · s(-1), P < .001). Accounting for walking speed reduced the sex difference to 19.2% and accounting for step length further reduced the difference to 13.4% (P < .001). Vertical axis counts · s(-1) were disproportionally greater in males even after adjustment for walking speed. This difference could confound free-living activity estimates.

Patterns of Objectively Measured Physical Activity in the United States

We used latent class analysis (LCA) to assess patterns of physical activity among adults, using the 7 d of accelerometer data from the 2003-2004 NHANES. For each participant, we determined the daily minutes of moderate-to-vigorous physical activity (MVPA), vigorous physical activity (VPA), and minutes of MVPA that occurred in bouts of 10 min. Participants were then categorized into patterns of activity, using LCA and adjusting for sociodemographic characteristics. For overall MVPA, five classes of physical activity were defined, including two least active classes, which averaged less than 25 min of MVPA per day and represented 78.7% of the total study population. The most active class averaged 134 min of MVPA per day and comprised 0.9% of the population. The results for bout minutes of MVPA were similar to the patterns produced for overall MVPA, with the exception of a "weekend warrior" class with moderate levels of physical activity Monday through Friday but with a much higher level of activity on the weekend, particularly on Sunday. This class represented 1.8% of the population. Only 1.4% of all days achieved 10 min or more of VPA, and in 91.1% of all days, participants accumulated less than 1 min of VPA. The LCA analysis of VPA did not produce stable results, because of the small number of participants registering any minutes of VPA. Our results indicate that a very large portion of the U.S. population may be classified into patterns of physical activity that represent low levels of MVPA throughout the week. The LCA analysis provided a novel approach for assessing patterns of objectively measured physical activity in epidemiologic studies.

The Ratio of Specific Polychlorinated Biphenyls as a Surrogate Biomarker of Cytochrome P4501A2 Activity—A Pharmaco-Metabonomic Study in Humans

The activity of cytochrome P4501A2 (CYP1A2) may be an important determinant of risk for certain cancers ([1][1], [2][2]). Phenotyping procedures, such as the caffeine breath test (CBT), have advantages over genotyping and have been used to characterize CYP1A2 activity in epidemiologic studies ([1][1

Assessment of Recreational Physical Activity During Pregnancy in Epidemiologic Studies of Birthweight and Length of Gestation: Methodologic Aspects

ABSTRACT In 2002, the American College of Obstetricians and Gynecologists revised their 1994 guidelines to recommend that pregnant women without medical or obstetric complications follow exercise guidelines for nonpregnant women. In spite of these guidelines, the optimal dose of recreational physical activity (i.e., total volume of energy expenditure, and specific frequency, duration and intensity) for a pregnant woman remains to be determined. Identification of this dose has been hampered by the complexity of assessing recreational physical activity in general, and particularly during pregnancy, a demanding period characterized by changing physiology. Therefore, we reviewed the measurement methods in the epidemiologic studies that examined the association between recreational physical activity and two specific pregnancy outcomes of primary public health importance, birthweight and length of gestation. From a review of the medical literature, we identified 20 published journal articles between 1966 and 2005. Study designs, participants, and physical activity assessment measures varied widely across studies. The majority of these studies did not consistently assess type, frequency, intensity, and duration of activity and did not measure these variables during each trimester of pregnancy. Because the effect of recreational physical activity on birth outcomes is likely to be modest, measurement must be highly accurate to minimize the possibility that an effect will not be observed because of measurement error. Recommendations are made for the future assessment of recreational physical activity in epidemiologic studies of these major birth outcomes.

Assessment of physical activity and energy expenditure in epidemiological research of chronic diseases

Physical inactivity has emerged as an important risk factor for a number of diseases, but the typically crude exposure assessments in epidemiological studies, with entailing variation in measurement accuracy, may be a source of heterogeneity contributing to inconsistent results among studies. Consequently, the choice of method for the assessment of physical activity in epidemiological studies is important. Good methods increase our chances of avoiding misclassification and may enhance our understanding of the association between physical activity and health. Since physical activity is also a potential confounder of other lifestyle-health relationships, good methods may enhance our ability to control for confounding. But despite a steadily increasing selection of methods to choose from, no method is suitable for every situation and every population. Although the questionnaire is the most widely used method in epidemiological studies, and laboratory methods are mainly used for validation purposes, improved technology may change our ways of assessing physical activity in the future. This paper describes different methods to measure physical activity and energy expenditure from the epidemiological perspective, and attempts to address the concepts related to the measurement of physical activity.

Desenvolvimento e validação de um questionário de avaliação da atividade física para adolescentes

To develop a physical activity questionnaire aimed at Brazilian adolescents and to assess its validity and reproducibility. A total of 94 adolescents (30 males and 64 females) aged 11-16 years were included in the study, which was conducted in 2004. The questionnaire comprised 17 questions on habitual physical activity in the last 12 months (15 questions on sports and physical exercise and two on transportation physical activity), and was standardized to yield final scores for weekly and yearly activity. As a reference, we used the multistage 20-meter shuttle run test, measuring variables maximum time in minutes, maximum speed, maximum oxygen uptake and maximum heart rate. For validity analysis, we used the Spearman coefficient and age-adjusted correlation. For reproducibility analysis, we repeated evaluations after 15 days and measured the intraclass correlation coefficient. For the weekly score, the highest correlations were obtained for maximum time for the entire sample (r=0.19), maximum speed for males (r=0.20), and both maximum oxygen uptake and maximum time for females (r=0.17). For the yearly score, the highest correlations were obtained for maximum time for the entire sample (r=0.30), maximum heart rate for males (r=0.22), and maximum time for females (r=0.23). In reproducibility analyses, correlations were 0.61 for weekly score and 0.68 for yearly score. The questionnaire was valid and reproducible. Its use is recommended for the evaluation of physical activity in epidemiological studies with adolescents.

Validity and Reliability of Self-Reported Total Energy Expenditure Using a Novel Instrument

Improved methods for quantitative self-reports of total physical activity in epidemiological studies are needed. We evaluated randomly selected individuals' ability to integrate their perception of physical activity over time to produce an estimate of the "usual" level, using a novel instrument for self-quantification of energy expenditure. A population-based sample of 418 Swedish men and women, age 20-59, completed a questionnaire containing the new instrument. For validation, three 24 hour recalls by phone served as gold standard. Reproducibility was assessed through administering the instrument another three times. The validation involved 133 subjects and another 160 completed the reproducibility evaluation. Pearson correlation between usual daily energy expenditure measured by the instrument and the mean of the 24 hour recalls was 0.73. After subdividing the self-reported daily energy expenditure and the mean of the 24 hour recalls into quintiles, 83.5% of the participants remained in the same quintile, or one quintile apart. There was a tendency towards overestimation of usual daily physical activity. This was significantly associated with low education. Reproducibility showed an intraclass correlation of 0.55. Although integrated reports of usual daily energy expenditure over longer periods seem to be afflicted with a tendency of overestimation, total energy expenditure can be estimated with reasonable validity and reproducibility using our instrument.

Validation of a simplified physical activity record by doubly labeled water technique

For obtaining reliable information about physical activity in epidemiological studies, validated and easy-to-use instruments are required. Therefore, a new simplified physical activity record based on 15-min recording intervals was developed and validated. Nonobese volunteers (n = 31). Physical activity was recorded over a 7-day period without detailed instructions. Energy expenditure was calculated (EE(sPAR)) and compared to energy expenditure measured by doubly labelled water technique (EE(DLW)). A good agreement between EE(sPAR) (12.1+/-3.0) and EE(DLW) (11.7+/-3.3) with a mean difference of 0.33+/-1.55 MJ (r = 0.880, P < 0.001) was observed. The absolute difference between EE(sPAR) and EE(DLW) was < 10% in 65% of the subjects. The difference between EE(sPAR) and EE(DLW) was independent of gender, age, body weight, and body mass index. A weak positive association between the difference and total body fat was observed (r = 0.618, P < 0.001), suggesting a slight tendency to overestimate EE(sPAR) with increasing total body fat. The new simplified physical activity protocol needs no detailed instructions, provides valid estimates of physical activity in nonobese free-living adults and can be used in epidemiological studies to assess total daily energy expenditure and physical activity level.

Reliability of the physical activity scale for the elderly (PASE)

Purpose: This article examines the reliability of the Physical Activity Scale for the Elderly (PASE) in a representative sample of Norwegian women and men. PASE is a brief and easily scored instrument to assess physical activity in epidemiological studies of persons age 65 years and older. Methods: A random sample (N = 343) of Norwegian women and men aged 67 years and over completed PASE. In addition, demographic information and health status was provided. Results: The mean PASE scores were higher in men than in women (men were more active than women), and higher in those aged 67–75 years compared with those aged 76 years and older. Internal consistency of PASE as measured by Cronbach's coefficient alpha was 0.73. Three hundred and twenty-seven subjects also completed follow-up questionnaires 3 days and 3 weeks later. The test-retest coefficient (Pearson's) reliability was 0.997 for the 3-day interval and 0.933 for the 3-week interval. Conclusion: The results show that PASE is an easily scored, reliable instrument for use in epidemiological studies to assess physical activity among Norwegian elderly men and women.