Patterns in blood pressure medication use in US incident dialysis patients over the first 6 months.
BACKGROUND
Several observational studies have evaluated the effect of a single exposure window with blood pressure (BP) medications on outcomes in incident dialysis patients, but whether BP medication prescription patterns remain stable or a single exposure window design is adequate to evaluate effect on outcomes is unclear.


METHODS
We described patterns of BP medication prescription over 6 months after dialysis initiation in hemodialysis and peritoneal dialysis patients, stratified by cardiovascular comorbidity, diabetes, and other patient characteristics. The cohort included 13,072 adult patients (12,159 hemodialysis, 913 peritoneal dialysis) who initiated dialysis in Dialysis Clinic, Inc., facilities January 1, 2003-June 30, 2008, and remained on the original modality for at least 6 months. We evaluated monthly patterns in BP medication prescription over 6 months and at 12 and 24 months after initiation.


RESULTS
Prescription patterns varied by dialysis modality over the first 6 months; substantial proportions of patients with prescriptions for beta-blockers, renin angiotensin system agents, and dihydropyridine calcium channel blockers in month 6 no longer had prescriptions for these medications by month 24. Prescription of specific medication classes varied by comorbidity, race/ethnicity, and age, but little by sex. The mean number of medications was 2.5 at month 6 in hemodialysis and peritoneal dialysis cohorts.


CONCLUSIONS
This study evaluates BP medication patterns in both hemodialysis and peritoneal dialysis patients over the first 6 months of dialysis. Our findings highlight the challenges of assessing comparative effectiveness of a single BP medication class in dialysis patients. Longitudinal designs should be used to account for changes in BP medication management over time, and designs that incorporate common combinations should be considered.
University of Minnesota College of Pharmacy, Minneapolis, MN, USA. wstpeter@cdrg.org.
Wendy L
WL
St Peter
Stephen M
SM
Sozio
Tariq
T
Shafi
Patti L
PL
Ephraim
Jason
J
Luly
Aidan
A
McDermott
Karen
K
Bandeen-Roche
Klemens B
KB
Meyer
Deidra C
DC
Crews
Julia J
JJ
Scialla
Dana C
DC
Miskulin
Navdeep
N
Tangri
Bernard G
BG
Jaar
Wieneke M
WM
Michels
Albert W
AW
Wu
L Ebony
LE
Boulware
D000959:Antihypertensive Agents / Q000145:classification / Q000627:therapeutic use*; D015984:Causality; D015897:Comorbidity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D055656:Prescriptions / Q000706:statistics & numerical data*; D015995:Prevalence; D006435:Renal Dialysis / Q000706:statistics & numerical data*; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology* / Q000534:rehabilitation*; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
D000959:Antihypertensive Agents