Each week, we select a recently published Open Access article to feature. This week’s article comes from Statistics in Medicine and proposes a regression model to determine the relationship between physical activity  and a health outcome of interest.

The article’s abstract is given below, with the full article available to read here. 

Jadhav, S, Tekwe, CD, Luan, Y. A function-based approach to model the measurement error in wearable devices. Statistics in Medicine. 2022; 1– 17. doi:10.1002/sim.9542

Physical activity (PA) is an important risk factor for many health outcomes. Wearable-devices such as accelerometers are increasingly used in biomedical studies to understand the associations between PA and health outcomes. Statistical analyses involving accelerometer data are challenging due to the following three characteristics: (i) high-dimensionality, (ii) temporal dependence, and (iii) measurement error. To address these challenges we treat accelerometer-based measures of PA as a single function-valued covariate prone to measurement error. Specifically, in order to determine the relationship between PA and a health outcome of interest, we propose a regression model with a functional covariate that accounts for measurement error. Using regression calibration, we develop a two-step estimation method for the model parameters and establish their consistency. A test is also proposed to test the significance of the estimated model parameters. Simulation studies are conducted to compare the proposed methods with existing alternative approaches under varying scenarios. Finally, the developed methods are used to assess the relationship between PA intensity and BMI obtained from the National Health and Nutrition Examination Survey data.