Validity of the Fitbit Charge HR fitness tracker for assessing physical activity of adults

Skrb za telesno dejavnost ima v vseh življenjskih obdobjih nenadomestljivo vlogo, saj ohranja in izboljšuje vitalnost človeka, ga varuje pred boleznimi in mu omogoča bolj kakovostno življenje. Vpliv telesne nedejavnosti na posameznika in njegovo zdravje je velik, saj je telesna nedejavnost na četrtem mestu med dejavniki tveganja za splošno umrljivost. Kljub poznanim pozitivnim lastnostim telesne dejavnosti, so ljudje v številnih državah po svetu po poročanju Svetovne zdravstvene organizacije premalo telesno dejavni. Vendar pa so ti podatki v številnih državah, med njimi tudi v Sloveniji, običajno zbrani s pomočjo vprašalnikov, ki temeljijo na samo-poročanju. To je najlažji način pridobivanja velikega števila podatkov, ki pa ima številne omejitve in nizko veljavnost. Posledično bi bilo primerno iskati objektivnejše metode merjenja, ki bi omogočale boljše in natančnejše spremljanje telesne dejavnosti posameznikov in populacije. Namen magistrske naloge je bil preučiti veljavnost pametne zapestnice. V raziskavi smo uporabili pametno zapestnico Fitbit Charge HR (Fitbit Inc., San Francisco, CA), ki smo jo primerjali z raziskovalnim pospeškometrom UKK RM42 (UKK Terveyspalvelut Oy, Tampere, Finska). V raziskavi je sodelovali 58 preizkušancev, ki so napravi nosili 6 oz. 7 dni, 24 ur na dan, razen pri tuširanju ali kakršnihkoli vodnih dejavnostih. V analizi smo uporabili podatke 53 preizkušancev, podatke pa smo obdelali s programoma IBM SPSS Statistics 22 (SPSS Inc., Chicago, ZDA) in Microsoft Excel (verzija 2013, Microsoft Corporation, Redmond, ZDA). Izračunali smo Pearsonov koeficient povezanosti in ugotovili, da med napravama pri merjenju povprečnega števila korakov na dnevni ravni obstaja srednje močna povezanost s koeficientom 0,64. Prav tako smo ugotovili, da je najvišja stopnja povezanosti med napravama v skupini, v kateri so posamezniki z ITM-jem višjim od 30. Hkrati je v tej skupini tudi največja razlika v povprečnem številu korakov na dnevni ravni in posledično tudi največja odstotna napaka. Rezultati naše študije predstavljajo doprinos k razmišljanjem o bolj objektivnem merjenju telesne dejavnosti populacije. Naši rezultati skladno z ugotovitvami predhodnih študij kažejo, da imajo pametne zapestnice višjo veljavnost kot vprašalniki. Menimo, da bi bilo primerno razmišljati o uporabi pametnih zapestnic za morebitno epidemiološko spremljanje telesne dejavnosti populacije. Hkrati se zavedamo tudi nekaterih slabosti, ki jih uporaba pametnih zapestnic prinaša.Physical activity is essential in all life stages because it maintains and improves a person’s vitality, protects them from diseases and improves the quality of their lives. Physical inactivity has a great impact on a person and their health since it is the fourth leading risk factor for global mortality. Despite the known benefits of physical activity people in many countries around the world are not physically active enough, according to the World Health Organization. This data is, in many countries including Slovenia, usually collected through questionnaires based on self-report method. This is the simplest way of collecting a large amount of information though it has many limitations and a low validity. Consequently, more objective measuring methods, providing better and more accurate measuring of an individual’s and population’s physical activity, should be searched for. The purpose of the thesis was to study the validity of a fitness tracker. The Fitbit Charge HR (Fitbit Inc., San Francisco, CA) fitness tracker was used in the research. It was compared to the research accelerometer UKK RM42 (UKK Terveyspalvelut Oy, Tampere, Finland). 58 people tested wore the devices 6 or 7 days, 24 hours a day, except when taking shower or during other water activities. In the analysis the data of 53 participants was used and processed using two programs: the IBM SPSS Statistics 22 (SPSS Inc., Chicago, USA) and Microsoft Excel (2013 version, Microsoft Corporation, Redmond, USA). Pearson’s correlation coefficient was calculated. We found that there is a moderately positive correlation (0,64) between the two devices when measuring the average daily step number. We also found that the strongest positive correlation between the two devices is in the group of individuals with the BMI higher than 30. There is also the most significant difference in the number of daily steps and thus the highest percent error. The results of our study are a contribution to the consideration of a more objective measurement of a population’s physical activity. The results are in accordance with the previous studies and show that fitness trackers have a higher validity than questionnaires. We believe that it would be advisable to consider the use of fitness trackers for a potential monitoring of a population’s physical activity. We are, nevertheless, aware of the disadvantages that the use of fitness trackers could bring