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Table 1 Factor analysis.

From: Cluster analysis in severe emphysema subjects using phenotype and genotype data: an exploratory investigation

 

Factor 1

Factor 2

Factor 3

Factor 4

Factor 5

Factor 6

Age, years

0.226

     

BMI, kg/m2

 

0.272

 

-0.123

0.117

 

Gender (% male)

0.181

-0.119

0.153

  

-0.712

Pack-years of smoking

     

0.187

Age started smoking

     

-0.237

Age quit smoking

0.146

0.14

   

-0.11

Pre-bronchodilator FEV1, % predicted

0.852

 

0.466

 

-0.181

0.1

Pre-bronchodilator FVC, % predicted

0.903

 

-0.247

  

0.154

Post-bronchodilator FEV1, % predicted

0.853

 

0.461

 

0.209

 

Post-bronchodilator FVC, % predicted

0.899

 

-0.301

 

0.172

0.193

Bronchodilator response, % of baseline FEV1

    

0.979

 

Bronchodilator response, absolute change in FEV1, L

0.163

   

0.943

0.183

FEV1/FVC ratio, post-bronchodilator

0.104

 

0.961

  

-0.134

FEV1/FVC ratio, pre-bronchodilator

  

0.902

 

-0.106

 

Total lung capacity, % predicted

 

-0.165

-0.227

0.151

  

Residual volume, % predicted

-0.506

 

-0.145

0.199

-0.132

 

Diffusion capacity, % predicted

0.169

 

0.219

-0.253

 

0.286

Total fraction emphysema at -950 HU

 

-0.214

-0.178

0.822

  

Difference between apical and basal emphysema at -950 HU

   

0.846

 

-0.108

Apical fraction emphysema at -950 HU

 

-0.141

 

0.981

  

Airway wall thickness, mm

 

0.96

    

Airway wall area, %

 

0.94

 

-0.114

  

Square root wall area, cm

 

0.882

    

6 minute walk distance, ft

0.175

-0.105

  

0.104

0.566

Maximum work, watts

0.174

 

0.135

-0.1

0.164

0.791

UCSD Shortness of Breath Questionnaire

-0.227

    

-0.307

Arterial pH

0.212

 

0.107

0.146

  

PaO2, mmHg

0.2

 

0.205

  

0.256

PaCO2, mmHg

-0.293

 

-0.345

-0.104

 

-0.166

Exacerbations in year prior to randomization

 

-0.123

   

-0.113

Exacerbations/year (over 3.3 years)

 

-0.107

-0.204

  

0.152

  1. Six factors were identified accounting for 75% of the common variance. Higher factor loadings indicate higher correlations of the variable with that factor. Loadings ≥ |0.1| are shown.