Korean J Fam Med. 2014;35:42-43

http://dx.doi.org/10.4082/kjfm.2014.35.1.42

Comments on Statistical Issues in January 2014

Commentary

Yong Gyu Park Department of Biostatistics, The Catholic University of Korea College of Medicine, Seoul, Korea

In this section, we suggest some guidelines for reporting

response variable has a normal distribution at each value of each

multiple linear regression analyses, which appeared in the article

explanatory variable. Sometimes, data that violate the assumptions

titled, “Factors associated with serum levels of carcinoembryonic

can be adjusted (for example, with data transformation) to meet

1)

antigen in healthy non-smokers”, by No et al. published in

the required assumptions. If such adjustments are made, it should

November 2013.

be noted.

GUIDELINES FOR REPORTING MULTIPLE LINEAR REGRESSION ANALYSES

2. Specify How the Final Results Were Derived Describe the process of selecting the best combination of explanatory variables when the variable selection methods such as stepwise, forward, or backward selection, were used. State whether explanatory variables were assessed for multi-collinearity

In statistics, the multiple linear regression analysis is an

and tested for interaction.

approach to model the relationship between a response variable collect data on several potential explanatory variables, determine

3. Report the Multiple Linear Regression Equation or Summarize the Equation in a Table

which variables are most strongly associated with the response

An example for reporting a multiple linear regression with

and several explanatory variables. Typically, a researcher will

variable, and then incorporate these variables into a mathematical

three explanatory variables is presented in Table 1.2)

model (a regression equation). The purpose of multiple linear regression analysis, then, is to identify which combination of

Table 1. Sample table for reporting a multiple linear regression

variables best predicts the response variable.

analysis

Here, we suggest some guidelines for reporting a multiple linear regression analysis.

1. State How Each Assumption Was Met and Checked A statement that the assumptions were verified is all that need be included. The assumptions of a multiple linear regression are as follows: 1) The relationship between each explanatory variable and response variable is linear; 2) The distributions of response variables have equal variances at each value of each explanatory variable; 3) Each response variable value is independent of one another for each value of each explanatory variable; and 4) The

42 |

Vol. 35, No. 1 Jan 2014

Variable

Coefficient

SE

95% CI

P-value

Intercept

40.79

2.55

-

-

X1

3.98

2.38

(-0.67, 8.63)

0.101

X2

1.23

0.29

(0.66, 1.80)

Comments on statistical issues in january 2014.

Comments on statistical issues in january 2014. - PDF Download Free
88KB Sizes 1 Downloads 0 Views