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Table 1 Characteristics of U.S. patients initiating peritoneal dialysis from 2007 to 2011 with Medicare Part D coverage

From: Renin-angiotensin system blockers and residual kidney function loss in patients initiating peritoneal dialysis: an observational cohort study

 

Full cohort

IPTW Cohort

Variable

Non-users

N = 497

ACEI/ARB users

N = 389

Std. diff.

Non-users

ACEI/ARB users

Std. diff.

Demographics

 Age (yr, mean ± SD)

67 ± 14

64 ± 13

0.22

66 ± 19

65 ± 19

0.05

 Male sex

56

56

0.00

56

57

0.02

 Race

  Black

16

17

0.03

16

16

0.00

  White

79

76

0.07

78

77

0.02

  Other

5

7

0.08

6

7

0.04

 Hispanic ethnicity

10

16

0.18

12

12

0.00

 Medicaid at time of dialysis initiation

26

34

0.18

28

28

0.00

Reported comorbidities

 Cancer

11

6

0.18

9

8

0.04

 Cardiac disease, othera

21

20

0.02

20

22

0.05

 Cerebrovascular disease

9

11

0.07

9

9

0.00

 Coronary artery disease

21

23

0.05

21

22

0.02

 Diabetes mellitus

55

64

0.18

60

58

0.04

 Heart failure

29

25

0.09

28

28

0.00

 Hyperkalemia

3

3

0.00

3

3

0.00

 Hyperlipidemia

18

18

0.00

18

18

0.00

 Hypertension

92

96

0.17

93

94

0.04

 Liver disease

2

1

0.08

1

2

0.08

 Peripheral vascular disease

15

16

0.03

15

15

0.00

 Pulmonary disease

15

13

0.06

14

14

0.00

 Tobacco use

7

7

0.00

7

7

0.00

 Days hospitalized in in the first 90 days of dialysis (median, IQR)

0 (0–0)

0 (0–0)

0.00

0 (0–0)

0 (0–0)

0.00

Baseline medication use

 ACEI or ARB

  ACEI

0

65

NA

0

65

NA

  ARB

0

42

NA

0

41

NA

  Both

0

6

NA

0

6

NA

 Beta blocker

63

61

0.04

63

62

0.02

 Calcium channel blocker

46

64

0.37

54

57

0.06

 Diuretic

56

66

0.21

61

59

0.04

 Other antihypertensiveb

40

48

0.16

43

44

0.02

 Statin

49

61

0.24

54

56

0.04

 Clopidogrel

12

13

0.03

13

14

0.03

 Warfarin

10

6

0.15

9

8

0.04

 Other cardiovascular medc

19

25

0.15

21

23

0.05

 Levothyroxine

17

18

0.03

18

18

0.00

Dialysis characteristics

 Saw nephrologist prior to dialysis initiation

88

88

0.00

87

89

0.06

 Year initiated dialysis

  2007

14

18

0.11

15

16

0.03

  2008

17

21

0.10

18

21

0.08

  2009

15

18

0.08

17

16

0.03

  2010

29

25

0.09

28

27

0.02

  2011

25

18

0.17

22

20

0.05

 CAPD (vs. CCPD)

32

40

0.17

35

36

0.02

Vital signs and laboratory measurements

 BMI (mean ± SD)d

28.3 ± 6

29.0 ± 6.4

0.11

28.4 ± 8

28.8 ± 9.7

0.04

 Hemoglobin (g/dL, mean ± SD)

10.7 ± 1.4

10.9 ± 1.5

0.14

10.7 ± 1.9

10.9 ± 2.2

0.10

 Albumin (g/dL, mean ± SD)

3.8 ± 0.5

3.8 ± 0.5

0.00

3.8 ± 0.6

3.8 ± 0.8

0.00

 Baseline rGFR (ml/min, mean ± SD)

8.4 ± 4.8

8.5 ± 4.7

0.02

8.3 ± 6.3

8.6 ± 7.2

0.07

 24 h urine volume (ml, median, IQR)

900 (550–1400)

1000 (600–1500)

0.07

850 (600–1400)

900 (600–1400)

0.01

Facility characteristics

 Number of PD patients (median, IQR)e

24 (14–39)

25 (14–39)

 

24 (14–39)

25 (14–39)

 

  ≥20

62

65

0.06

62

62

0.00

 Ruralf

14

15

0.03

15

15

0.00

 Geographic location (U.S. census division)g

  East North Central

12

13

0.03

13

12

0.03

  East South Central

7

8

0.04

8

7

0.04

  Middle Atlantic

8

6

0.08

7

8

0.04

  Mountain

5

3

0.10

4

5

0.05

  New England

5

3

0.10

5

3

0.10

  Pacific

10

16

0.18

13

14

0.03

  South Atlantic

29

27

0.04

28

27

0.02

  West North Central

10

8

0.07

10

10

0.00

  West South Central

13

15

0.06

13

14

0.03

  1. All numbers are percentages unless indicated otherwise. ACEI angiotensin-converting enzyme inhibitor, ARB angiotensin-II receptor blocker, BMI body mass index, CAPD continuous ambulatory peritoneal dialysis, CCPD continuous cycling peritoneal dialysis, eGFR estimated glomerular filtration rate, IQR interquartile range, IPTW inverse probability of treatment weighted, PD peritoneal dialysis, SD standard deviation, Std. Diff. standardized difference
  2. aIncludes atrial fibrillation, arrhythmias, implanted cardiac defibrillators, pacemakers, and valvular disease
  3. bIncludes alfuzosin, aliskiren, clonidine, doxazosin, guanfacine, hydralazine, isosorbide, methyldopa, minoxidil, prazosin, ranolazine, and terazosin
  4. cIncludes ezetimibe, simvastatin, niacin, amiodarone, aspirin/dipyridamole, colesevelam, colestipol, digoxin, dipyridamole, dronedarone, fenofibrate, flecainide, gemfibrozil, mexiletine, nitroglycerin, omega-3 acid ethyl esters, procainamide, propafenone, and quinidine
  5. dMissing for 11% of non-users and 1% of users
  6. eBased on the year the patient initiated dialysis
  7. fFacilities were considered urban if they were classified as a metropolitan area in the Rural–Urban Commuting Area (RUCA) Codes version 2.0, which are based on 2000 Census commuting data and 2004 zip codes; all other areas were considered to be rural [24]
  8. gFacilities were categorized into one of nine U.S. Census Bureau Divisions based on their state [25]