Skip to main content

Table 3 Selected characteristics and standardized differences of linked and non-linked infants

From: Development and evaluation of an algorithm to link mothers and infants in two US commercial healthcare claims databases for pharmacoepidemiology research

 

CCAE

Clinformatics®

Characteristic

Linked

% (n = 2,528,482)

Non-linked

% (n = 2,406,894)

SMD

Linked

% (n = 1,589,010)

Non-linked

% (n = 1,790,801)

SMD

Sex

      

gender = FEMALE

48.71

48.66

-0.001

48.57

48.55

0

gender = MALE

51.29

51.34

0.001

51.43

51.45

0

Index year

      

2000

0.09

1.08

0.13

0.01

3.87

0.283

2001

0.64

1.07

0.046

2.01

6.89

0.238

2002

1.14

2.54

0.104

4.27

4.93

0.032

2003

2.21

3.95

0.101

4.82

4.66

-0.008

2004

3.32

4.3

0.051

4.78

4.49

-0.014

2005

4.08

4.44

0.018

5.07

6.65

0.067

2006

4.03

4.99

0.047

6.37

6.06

-0.013

2007

4.81

4.8

0

6.3

5.97

-0.014

2008

5.26

6.23

0.042

6.26

5.06

-0.052

2009

6.38

6.57

0.008

5.81

4.13

-0.077

2010

6.17

7.5

0.053

4.79

3.56

-0.062

2011

7.65

7.35

-0.011

4.49

3.52

-0.05

2012

8.04

7.25

-0.03

4.39

3.51

-0.045

2013

6.7

6.32

-0.015

5.08

3.99

-0.052

2014

6.98

6.29

-0.028

4.56

4.02

-0.026

2015

5.45

4.15

-0.061

4.47

4.68

0.01

2016

5.44

4.1

-0.063

4.73

4.84

0.005

2017

4.95

4.02

-0.045

4.68

4.68

0

2018

4.91

4.47

-0.021

4.8

4.44

-0.017

2019

4.97

3.65

-0.065

4.74

4.04

-0.034

2020

4.43

3.43

-0.051

4.34

3.49

-0.044

2021

2.34

1.49

-0.062

3.24

2.54

-0.042

Index month

      

1

4.78

4.57

-0.01

7.42

6.15

-0.05

2

7.11

6.37

-0.03

7.39

5.91

-0.059

3

8.24

7.42

-0.031

8.3

6.73

-0.06

4

8.8

8.49

-0.011

8.15

6.97

-0.045

5

8.67

8.58

-0.003

8.54

10.15

0.056

6

8.64

9.04

0.014

8.47

8.5

0.001

7

9

10.52

0.052

8.79

9.93

0.039

8

8.53

9.88

0.047

8.93

9.57

0.022

9

8.42

10.31

0.065

8.74

9.95

0.041

10

9.66

9.67

0

8.78

9.38

0.021

11

9.32

7.88

-0.051

8.3

8.32

0.001

12

8.84

7.28

-0.057

8.19

8.44

0.009

Post observation time (days)*

      

Mean

1060.01

886.47

-0.106

855.02

751.11

-0.091

Std. deviation

1206.57

1113.97

 

1103.29

985.63

 

Median

618

486

 

431

395

 

Distinct conditions

      

Mean

6.81

5.73

-0.115

7.75

6.39

-0.13

Std. deviation

6.9

6.39

 

7.64

7.11

 

Median

5

4

 

6

5

 

Distinct drug ingredients

      

Mean

2.69

2.45

-0.049

8.55

7.44

-0.066

Std. deviation

3.43

3.38

 

12.05

11.76

 

Median

1

1

 

2

2

 

Procedures

      

Mean

11.55

9.87

-0.164

12.28

9.99

-0.213

Std. deviation

7.42

7

 

7.83

7.36

 

Median

10

9

 

11

9

 

Distinct measurements

      

Mean

2.63

2.23

-0.056

3.29

2.83

-0.044

Std. deviation

4.96

4.92

 

7.43

7.61

 

Median

1

1

 

1

1

 

Distinct visit types

      

Outpatient Visit

      

Mean

10.09

8.65

-0.155

9.47

8.32

-0.107

Std. deviation

6.65

6.46

 

7.74

7.51

 

Median

9

8

 

9

7

 

Inpatient Visit

      

Mean

0.67

0.5

-0.236

1.03

0.69

-0.494

Std. deviation

0.51

0.57

 

0.47

0.51

 

Median

1

0

 

1

1

 

Emergency Room Visit

      

Mean

0.22

0.24

0.016

0.1

0.13

0.006

Std. deviation

0.84

0.91

 

3.95

3.45

 

Median

0

0

 

0

0

 
  1. CCAE: IBM Commercial Database; Clinformatics®: Optum’s de-identified Clinformatics® Data Mart Database; SMD.: Standardized difference of means
  2. *Post-index observation time was measured from the linked mother’s delivery date (true birth date) to end of observation time
Back to article page

BMC Medical Research Methodology

ISSN: 1471-2288

Contact us