Limits...
Physical activity in German adolescents measured by accelerometry and activity diary: introducing a comprehensive approach for data management and preliminary results.

Pfitzner R, Gorzelniak L, Heinrich J, von Berg A, Klümper C, Bauer CP, Koletzko S, Berdel D, Horsch A, Schulz H, GINIplus Study Gro - PLoS ONE (2013)

Bottom Line: Girls also frequently reported dancing and gymnastics (23%).The diary is vital for the identification of invalid data and non-compliant participants.Preliminary results suggest that four out of five German adolescents do not meet WHO recommendations for PA and that school sport contributes only little to MVPA.

View Article: PubMed Central - PubMed

Affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.

ABSTRACT

Introduction: Surveillance of physical activity (PA) is increasingly based on accelerometry. However, data management guidelines are lacking. We propose an approach for combining accelerometry and diary based PA information for assessment of PA in adolescents and provide an example of this approach using data from German adolescents.

Methods: The 15-year-old participants comprised a subsample the GINIplus birth cohort (n = 328, 42.4% male). Data on PA was obtained from hip-worn accelerometers (ActiGraph GT3X) for seven consecutive days, combined with a prospective activity diary. Major aspects of data management were validity of wear time, handling of non-wear time and diary comments. After data cleaning, PA and percentage of adolescents meeting the recommendations for moderate-to-vigorous activity (MVPA) per day were determined.

Results: From the 2224 recorded days 493 days (25%) were invalid, mainly due to uncertainties relating to non-wear time (322 days). Ultimately, 269 of 328 subjects (82%) with valid data for at least three weekdays and one weekend day were included in the analysis. Mean MVPA per day was 39.1 minutes (SD ±25.0), with boys being more active than girls (41.8±21.5 minutes vs. 37.1±27.8 minutes, p<0.001). Accordingly, 24.7% of boys and 17.2% of girls (p<0.01) met the WHO recommendations for PA. School sport accounted for only 6% of weekly MVPA. In fact, most MVPA was performed during leisure time, with the majority of adolescents engaging in ball sports (25.4%) and endurance sports (19.7%). Girls also frequently reported dancing and gymnastics (23%).

Conclusion: For assessment of PA in adolescents, collecting both accelerometry and diary-based information is recommended. The diary is vital for the identification of invalid data and non-compliant participants. Preliminary results suggest that four out of five German adolescents do not meet WHO recommendations for PA and that school sport contributes only little to MVPA.

Show MeSH
Exclusion of recorded days due to quality control in the ongoing GINIplus study.(NWT: non-wear time, NWT-sport: non-wear time during sport activities, algorithm: NHANES algorithm for detecting NWT [33]).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3672153&req=5

pone-0065192-g003: Exclusion of recorded days due to quality control in the ongoing GINIplus study.(NWT: non-wear time, NWT-sport: non-wear time during sport activities, algorithm: NHANES algorithm for detecting NWT [33]).

Mentions: Specific events throughout the 7 days measuring period were considered as not being representative and, thus, the days were excluded from the analysis. Days with a diary reported common cold or headache were included in the analysis as was one day sick with staying in bed. But two or more days sick were excluded from the second day on. Accordingly, one day trips were included, whereas two and more days on a trip during the week, for example due to a school excursion, were excluded from the analysis. In case that for all 7 measuring days no information about NWT was provided by the participant, days were excluded from analysis (18 days). Sensor forgotten to wear was classified as NWT. In case the sensor was worn incorrectly (upside down or on hand instead of hip), or a flashing LED was reported suggesting technical issues, the corresponding days were excluded from the analysis (50 days, Figure 3).


Physical activity in German adolescents measured by accelerometry and activity diary: introducing a comprehensive approach for data management and preliminary results.

Pfitzner R, Gorzelniak L, Heinrich J, von Berg A, Klümper C, Bauer CP, Koletzko S, Berdel D, Horsch A, Schulz H, GINIplus Study Gro - PLoS ONE (2013)

Exclusion of recorded days due to quality control in the ongoing GINIplus study.(NWT: non-wear time, NWT-sport: non-wear time during sport activities, algorithm: NHANES algorithm for detecting NWT [33]).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672153&req=5

pone-0065192-g003: Exclusion of recorded days due to quality control in the ongoing GINIplus study.(NWT: non-wear time, NWT-sport: non-wear time during sport activities, algorithm: NHANES algorithm for detecting NWT [33]).
Mentions: Specific events throughout the 7 days measuring period were considered as not being representative and, thus, the days were excluded from the analysis. Days with a diary reported common cold or headache were included in the analysis as was one day sick with staying in bed. But two or more days sick were excluded from the second day on. Accordingly, one day trips were included, whereas two and more days on a trip during the week, for example due to a school excursion, were excluded from the analysis. In case that for all 7 measuring days no information about NWT was provided by the participant, days were excluded from analysis (18 days). Sensor forgotten to wear was classified as NWT. In case the sensor was worn incorrectly (upside down or on hand instead of hip), or a flashing LED was reported suggesting technical issues, the corresponding days were excluded from the analysis (50 days, Figure 3).

Bottom Line: Girls also frequently reported dancing and gymnastics (23%).The diary is vital for the identification of invalid data and non-compliant participants.Preliminary results suggest that four out of five German adolescents do not meet WHO recommendations for PA and that school sport contributes only little to MVPA.

View Article: PubMed Central - PubMed

Affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.

ABSTRACT

Introduction: Surveillance of physical activity (PA) is increasingly based on accelerometry. However, data management guidelines are lacking. We propose an approach for combining accelerometry and diary based PA information for assessment of PA in adolescents and provide an example of this approach using data from German adolescents.

Methods: The 15-year-old participants comprised a subsample the GINIplus birth cohort (n = 328, 42.4% male). Data on PA was obtained from hip-worn accelerometers (ActiGraph GT3X) for seven consecutive days, combined with a prospective activity diary. Major aspects of data management were validity of wear time, handling of non-wear time and diary comments. After data cleaning, PA and percentage of adolescents meeting the recommendations for moderate-to-vigorous activity (MVPA) per day were determined.

Results: From the 2224 recorded days 493 days (25%) were invalid, mainly due to uncertainties relating to non-wear time (322 days). Ultimately, 269 of 328 subjects (82%) with valid data for at least three weekdays and one weekend day were included in the analysis. Mean MVPA per day was 39.1 minutes (SD ±25.0), with boys being more active than girls (41.8±21.5 minutes vs. 37.1±27.8 minutes, p<0.001). Accordingly, 24.7% of boys and 17.2% of girls (p<0.01) met the WHO recommendations for PA. School sport accounted for only 6% of weekly MVPA. In fact, most MVPA was performed during leisure time, with the majority of adolescents engaging in ball sports (25.4%) and endurance sports (19.7%). Girls also frequently reported dancing and gymnastics (23%).

Conclusion: For assessment of PA in adolescents, collecting both accelerometry and diary-based information is recommended. The diary is vital for the identification of invalid data and non-compliant participants. Preliminary results suggest that four out of five German adolescents do not meet WHO recommendations for PA and that school sport contributes only little to MVPA.

Show MeSH