INTRODUCTION Physical therapists n...

INTRODUCTION

Physical therapists ne an understanding of when and to what end to use different statistical exhibitions not only when conducting research still also when reviewing research articles. The first grade in selecting a statistical example or evaluating the appropriateness of a statistical ordeal used in a study is to identify the drift of the study, outcome variable(s), and contemplation design. Next, classify the end of statistical analysis in the cogitation as one of the following: 1) to determine the significance of the difference among cluster means, 2) to evaluate the stage of relationship between two variables, or 3) to predict undivided variable based on another. After classifying the "statistical" intent of the study, determine the archetype of measurement scale(s) used in data acquisition (nominal, ordinal, interval, ratio). In addition, when selecting or evaluating statistical conducts you must decide if a parametric or nonparametric trial is most appropriate if evaluating ratio or interval data. Parametric assumptions include random sample selection, normally distributed population, and homogeneity of variance. When evaluating statistical deeds in previously published studies, it is usually difficult to determine if parametric assumptions were met unles the authors disclose information forward whether or not the data consider probableed passed tests of normality and homogeneity of variance. frequently it is also necessary to determine for what reason many groups or comparisons are in the thought design, whether the data are independent (unpaired) or pendent (paired), and the sample size. The decision making proces in selecting or evaluating statistical proofs is illustrated in the Figure. For a review of statistical practices refer to the article "The When and on what account of Statistical Tests" or a physical therapy research textbook1-7 The intention of this article is to current several case scenarios in cardiopulmonary physical therapy research to illustrate appropriate statistical application.

CASE # 1

Title. Use of the Six-Minute Walk/Run proof to Predict Peak Oxygen Consumption in Older Adults'

Purpose To predict treadmill peak VO using the sixminute walk trial in healthy older adults.

Outcome Variables. Variables measured during treadmill testing included peak VO (ml/kg/min), peak respiratory exchange ratio (%) peak heart rate (bpm) and percent of predicted maximum heart rate (bpm) Variables measured during six-minute walk testing included maximal walking distance (m) and ending heart rate (bpm) Data forward subject characteristics were also garner uped including age (years), height (m) weight (kg) and percent corpse fat (%).

Study Design. Repeated measurements (treadmill trial and multiple trials of six-minute walk test) were taken onward a single group of exposes (n=30).

What is the final cause of statistical analysis?

The drift of statistical analysis in this investigation was to predict one variable (peak VO^sub 2^) based forward another variable(s).

What sign of measurement scale(s) was used in data collection?

All of the measurements in this application of mind VO^sub 2^, (ml/kg/min), respiratory exchange ratio, heart rate (bpm) distance/height (m) age (years), weight (kg) and material substance fat M), produced ratio data. When data is give vent toed as a percent or ratio, the underlying measurements must be identified in order to determine what category of measurement scale was in use. In this case, the respiratory exchange ratio is a contortion divided by a volume and percent material substance fat is a weight divided on a weight and therefore these would be classified as ratio data.

How many form into groupss and/or comparisons were made?

In this studious mood only 1 group of make subordinates was used making the data paired. Comparisons were made among the treadmill touchstone and multiple trials of the six-minute walk proof

What is the appropriate statistical analysis to employ?

Since the aim ot statistical analysis in this studious mood was to predict VO^sub 2^ from six-minute walk examples variables, than regression analysis is the appropriate statistical practice to use. For the greatest in quantity part regression analysis obligates the use of ratio/interval data and requires paired measurements. frequently correlational analysis precedes regression analysis to determine which issue variables have the greatest measure of relationship and therefore should be used in the regression equation.

CASE # 2

Title. Walking and Running [i]vis viva[/i] Expenditure Estimated by the Tritrac and Indirect Calorimetry9

Purpose To determine the validity of the Tritrac during walking and running at specified make hastes between 2 and 8 mph

Outcome Variables. The consequence variable in this study was spiritedness expenditure (kcal/min) measured by motion sensor (Tritrac) and indirect calorimetry.

Study Design. Simultaneous measurements of might expenditure via Tritrac and indirect calorimetry were taken upon a single group of make submissives (n=1 0).

What is the project of statistical analysis?

The view of statistical analysis in this reflection was to determine the validity of a measurement instrument. In this case validity is evaluated from assessing the degree of relationship between values obtained from the instrument in question (Tritrac) and those obtained using a criterion or "gold-standard" technique (indirect calorimetry).