Measurement Repeatability of Central and Peripheral Blood Pressures: The ARIC Study

Minimal Detectable Change in Resting Blood Pressure and Cardiorespiratory Fitness: A Secondary Analysis of a Study on School-Based High-Intensity Interval Training Intervention

High-intensity interval training (HIIT) effects on resting blood pressure (BP) and cardiorespiratory fitness (CRF) have already been studied. Furthermore, the responses of responders and non-responders to HIIT in terms of these physiological outcomes have also been examined. However, the minimal detectable change (MDC) in BP and CRF has not been addressed yet. Therefore, the current study aimed to compare the MDC90 of BP (systolic and diastolic) and CRF (fitness index (FI) results) in the context of a school-based HIIT program for adolescents. Participants were adolescents, with an average age of 16.16 years (n = 141; 36.6% males). A preplanned secondary analysis was conducted using pre-post data from the control group to estimate MDC90. The MDC90 of SBP, DBP, and FI were 7.82 mm HG, 12.45 mm HG, and 5.39 points, respectively. However, taking into account the relative values of these changes, MDC90 required a greater change in DBP (17.27%) than FI (12.15%) and SBP (6.68%). Any training-induced physiological changes in the average values of the outcomes did not exceed MDC90. However, a comparison of the participants who exceeded and did not exceed MDC90 showed statistically significant differences. These findings reveal the huge variability in and insensitivity to the intervention effect for all measurements. This is likely because of the large subgroup of participants with low sensitivity to the physiological stimulus. As such, there is a considerable need to create individually tailored intervention programs.

Reliability of an instrument for screening hand profiles: The Practical Hand Evaluation

STUDY DESIGN

Psychometric study with 2-week interval.

INTRODUCTION

Musculoskeletal hand complaints are common among manual workers. Mismatch between anthropometric hand features and tasks can affect the ability to perform hand activities, with an increased risk of complaints. Although screening of these features may improve diagnosis and treatment, no validated screening tool is available. The Practical Hand Evaluation (PHE) screening tool might fill this gap, but its psychometric properties are unknown.

PURPOSE OF THE STUDY

To test the reliability of the PHE and to explore the feasibility of item reduction of the PHE.

METHODS

Right-hand profiles of 117 healthy volunteers (66 women, 51 men; mean age, 22.8 years) were independently assessed 4 times by 6 couples of researchers using the PHE, twice on day 1 and twice 2-3 weeks later. Intrarater and inter-rater reliability (intraclass correlations), standard error of measurement (SEM), potential confounding factors (gender, joint hyperlaxity, and measurement order) affecting the instrument's reliability (limits of agreement), and collinearity between the PHE items were determined (variation inflation factor analysis and hierarchical clustering of correlation coefficients).

RESULTS

The intrarater and inter-rater reliabilities of the PHE were good for 12 of 14 items (86%; r = 0.67-0.90). Absolute SEM varied between 2.01 and 9.23 mm. The percentage of shifts of at least 2 classes in a repeated measurement was <15%. Cluster analysis identified 6 clusters of hand items.

DISCUSSION

The reliability for nearly all PHE items is good. Measurement errors were substantial relative to variances in the reference population, but not to gender, joint laxity and order of administration. Clustering into 6 seperated clusters of items was possible.

CONCLUSIONS

The PHE fulfills many of the criteria for screening of anthropometrics of the hand. Its reliability is high. The SEM might be improved with future adaptations toward a digital photographic PHE. Reduction to 6 items seems also possible.