multiple regression example a hospital administrator wished to study the relation between patient...

Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity of illness (X 2 ), and anxiety level (X 3 ). The administrator randomly selected 23 patients a collected the following data where larger values of Y, X 2 , and X 3 are, respectively, associated with

Upload: domenic-fisher

Post on 18-Jan-2018

233 views

Category:

Documents

0 download

Report

Download

Embed Size (px):

DESCRIPTION

Backward Elimination

TRANSCRIPT

Page 1: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Multiple Regression ExampleA hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X1), severity of illness (X2), and anxiety level (X3). The administrator randomly selected 23 patients a collected the following data where larger values of Y, X2, and X3 are, respectively, associated with more satisfaction, increased severity of illness, and more anxiety. The data is of the form (X1, X2, X3,Y).

Page 2: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 3: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Backward Elimination

Page 4: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 5: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 6: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 7: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 8: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 9: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Forward Selection

Page 10: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 11: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 12: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 13: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 14: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 15: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 16: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 17: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 18: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Reduced Sets of j’s

Page 19: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 20: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 21: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

All “Possible” Models; X1,X2 Only

Page 22: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 23: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 24: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Page 25: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Multicollinearity Example

The following data is a portion of that from a study of the relation of the amount of body fat (Y) to the predictor variables (X1) Tricep skinfold thickness, (X2) Thigh circumference, and (X3) Midarm circumference based on a sample of 20 healthy females 25-34 years old.

Page 26: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Subject Triceps Thigh Midarm Body Fat1 19.5 43.1 29.1 11.92 24.7 49.8 28.2 22.83 30.7 51.9 37 18.7… … … … …18 30.2 58.6 24.6 25.419 22.7 48.2 27.1 14.820 25.2 51 27.5 21.1

Page 27: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

The L.S. regression coefficients for X1 and X2 of various models are given in the table

Variables in Model b1 b2X1 0.8572 …X2 … 0.8565

X1, X2 0.224 0.6594X1, X2, X3 4.334 -2.857

Page 28: Multiple Regression Example A hospital administrator wished to study the relation between patient satisfaction (Y) and the patient’s age (X 1 ), severity

Hence, the regression coefficient of one variable depends upon which other variables are in the model and which ones are not. Therefore, a regression coefficient does not reflect any inherent effect of particular predictor variable on the response variable (Only a partial effect, given what other variables are included)

Wound severity

A Patient’s Guide to Cardiac Surgery€¦ · A Patient’s Guide to Cardiac Surgery ... surgery.

Severity Exposed -

EDITORIAL - dmp.umed.wroc.pl · The optimum maxillary expansion approach should be chosen based on such unambiguous criteria as patient’s age, severity of deformity and the skills

Supporting every patient’s journey

DISTRIBUTE OR COPY NOT DO MATERIAL- COPYRIGHTED · of the disease separately: The presence and severity of the spirometric abnormality Current nature and magnitude of the patient’s

Pharmacovigilance Methods - Uppsala University · • To establish a functional reporting system to monitor the safety of all medicines ... patient’s file, regardless of its severity

New Patient’s Information

Comparing the CR-3 Injury Severity Categories to Injury Severity Metrics

Injury Severity Principles

Mapping Burn Severity

Impact of clinical severity of stroke on the severity and ... fileRESEARCH ARTICLE Impact of clinical severity of stroke on the severity and recovery of visuospatial neglect Tanja