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IIR 07-165 – HSR&D Study

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IIR 07-165
Impact of Medicare Drug Benefit on VA Drug Use, Healthcare Use and Cost
Kevin T. Stroupe PhD MA BS
Edward Hines Jr. VA Hospital, Hines, IL
Hines, IL
Funding Period: January 2011 - June 2013

BACKGROUND/RATIONALE:
Over 40% of Veterans eligible for VA healthcare are enrolled in Medicare. Beginning January 2006, drug coverage was available to all Medicare enrollees through Medicare Part D. Individuals with Medicare coverage, including Veterans receiving care at VA, could begin enrolling in Part D from 11/2005-5/2006. For those who enrolled in Part D, coverage began January 2006 or the first day of the month following enrollment. Subsequent enrollment periods were November through December of each year with coverage beginning the following January. Many dual (VA and Medicare) users may be receiving care at the VA primarily to obtain the VA pharmacy benefit, which requires a prescription from a VA physician. Thus, the availability of Part D could lead some Veterans to alter their patterns of use of VA and Medicare-covered services. Consequently, the extent of Veterans' enrollment in Part D and the overall impact of Part D on medication acquisition from VA and healthcare use and costs in VA and Medicare were unknown.

OBJECTIVE(S):
The primary objectives were to determine 1) the extent of Veterans' enrollment in Part D and 2) the impact of Part D on use of VA and Medicare-covered services.

METHODS:
We identified Veterans who met Medicare's age eligibility in 2004 (i.e., Veterans who were 65 years of age or older on January 1, 2004) in the VA Vital Status File. We took a random 10% sample of male and all female Veterans from this file who were 65 years of age or older as of January 1, 2004, and were presumed alive as of December 31, 2006. Based on these eligibility criteria, we identified 327,100 Veterans: 270,445 male and 56,655 female Veterans. For the first objective, we examined the proportion of our cohort who were enrolled from 2006 through 2009, and we compared characteristics of those who enrolled vs. did not enroll.

For the second objective, we compared medication acquisition from VA, VA and Medicare service use in 2005 (before Part D was implemented) and 2007 (after Part D was implemented) between Veterans who were or were not enrolled in Part D. We excluded 2006 because this start-up period may not be representative of the on-going program. We identified the association of the Part D program with these outcomes using a difference-in-differences approach by comparing the difference in outcomes between 2007 and 2005 for Veterans who did and did not enroll in Part D. We implemented the difference-in-differences approach by first matching patients who were or were not enrolled in Part D in 2007 using propensity scores. Then, we estimated the association of Part D with our outcomes using generalized estimating equations (GEE). We identified the difference-in-differences using the interaction term of enrollment and time in the GEE model. Because of potential gender differences in medication and healthcare utilization patterns, we examined men and women separately.

FINDINGS/RESULTS:
There were 320,019 Veterans with complete data who were included in the enrollment analyses. Veterans averaged 77.5 (6.1 SD) years old in 2006. Overall, 31.9% enrolled in Part D in 2006, and 40.9% were enrolled some time between 2006 and 2009. Veterans who were enrolled in Part D in 2006 had significantly higher odds than Veterans not enrolled of being male (OR=1.11, p<0.001), Hispanic (OR=1.34, p<0.001), and having higher co-morbidity scores (OR=1.20, p<0.001). Older Veterans also had higher odds of enrollment; Veterans between the ages of 71-75 had 1.17 higher odds of enrolling in 2006 than younger Veterans. Among Veterans who enrolled in 2006, 7.7% quit in 2007, and an additional 3.6% (3.6%) quit in 2008 (2009). Characteristics significantly associated with quitting in 2007 included having higher numbers of VA prescriptions in 2006 (OR=1.01, p<0.001), being African-American (OR=1.23, p<0.001), and having a lower co-morbidity score (OR=0.81, p<0.000).

There were 236,764 men (50,141 women) with complete data who were alive throughout 2007. We performed one-to-one nearest neighbor propensity matching, resulting in 75,120 men (15,766 women) enrolled in Part D in 2007 and a similar number who were not enrolled. We examined the number of 30-day equivalent supplies of medications that Veterans received from VA pharmacies. Consistent with our hypothesis of decreased VA pharmacy use for enrolled Veterans, difference-in-differences testing revealed that the number of 30-day drug supplies increased from 31 in 2005 to 35 in 2007 for male Veterans not enrolled but decreased from 31 in 2005 to 29 in 2007 for enrolled Veterans (p<0.001 both). GEE analysis indicated a 17% reduction in medication acquisition from VA pharmacies for male Veterans enrolled in Part D (incidence rate ratio [IRR]=0.83, p<0.001) relative to those not enrolled. Similarly, there was a 19% reduction in medication acquisition from VA pharmacies for female Veterans enrolled in Part D (IRR=0.81, p<0.001).

Consistent with our hypothesis that Veterans who enrolled in Part D decreased utilization of VA services, we found that VA primary care visits decreased by 14% (IRR=0.865, p<0.001) for men and 15% for women (IRR=0.852, p<0.001) who enrolled relative to those not enrolled. VA inpatient length of stay also decreased by 6% (IRR=0.936, p<0.001) for men and 22% for women (IRR=0.784, p<0.001). However, the findings about Part D enrollment and use of Medicare-covered services were not consistent. For both men and women, Medicare-covered primary care decreased for patients enrolled in Part D relative to those not enrolled but the length of stay for Medicare-covered inpatient admissions increased.

IMPACT:
Between 2006-2009, 40.9% of patients meeting Medicare's age eligibility were enrolled in Part D. While Part D may increase options for obtaining medications among Veterans using VA healthcare, non-VA medication coverage might also complicate coordination among multiple prescribers. Through a previous survey of Veterans, we found that a substantial portion of Veterans were not discussing non-VA medications with VA physicians. Consequently, our current results highlight the importance of medication reconciliation efforts to account for non-VA pharmacy use, especially among Medicare-eligible VA users.

PUBLICATIONS:

Journal Articles

  1. Markossian TW, Kramer HJ, Burge NJ, Pacold IV, Leehey DJ, Huo Z, Schneider J, Ling B, Stroupe KT. Statin use among Veterans with dialysis-dependent chronic kidney disease. Hemodialysis international. International Symposium on Home Hemodialysis. 2019 Apr 1; 23(2):206-213.
  2. Markossian TW, Suda KJ, Abderhalden L, Huo Z, Smith BM, Stroupe KT. Characteristics and medication use of veterans in Medicare Advantage plans. The American journal of managed care. 2018 May 1; 24(5):247-255.
  3. Hatch MN, Raad J, Suda K, Stroupe KT, Hon AJ, Smith BM. Evaluating the Use of Medicare Part D in the Veteran Population With Spinal Cord Injury/Disorder. Archives of physical medicine and rehabilitation. 2018 Jun 1; 99(6):1099-1107.
  4. Suda KJ, Smith BM, Bailey L, Gellad WF, Huo Z, Burk M, Cunningham F, Stroupe KT. Opioid dispensing and overlap in veterans with non-cancer pain eligible for Medicare Part D. Journal of the American Pharmacists Association : JAPhA. 2017 May 1; 57(3):333-340.e3.
  5. Stroupe KT, Smith BM, Bailey L, Adas J, Gellad WF, Suda K, Huo Z, Tully S, Burk M, Cunningham F. Medication acquisition by veterans dually eligible for Veterans Affairs and Medicare Part D pharmacy benefits. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists. 2017 Feb 1; 74(3):140-150.
  6. Spencer SH, Suda KJ, Smith BM, Huo Z, Bailey L, Stroupe KT. Erectile Dysfunction Medication Use in Veterans Eligible for Medicare Part D. Journal of managed care & specialty pharmacy. 2016 Jul 1; 22(7):818-24.
  7. Stroupe KT, Bailey L, Gellad WF, Suda K, Huo Z, Martinez R, Burk M, Cunningham F, Smith BM. Veterans' Pharmacy and Health Care Utilization Following Implementation of the Medicare Part D Pharmacy Benefit. Medical care research and review : MCRR. 2017 Jun 1; 74(3):328-344.
Government Briefings

  1. Stroupe KT, Smith BM, Bailey LA. Substantial Portion of Elderly Veterans Receive Medications from Medicare Part D-Reimbursed Pharmacies - Either Alone or in Conjunction with VA Pharmacies: Briefing before the VHA Senior Leadership (included the VA Under Secretary for Health, Deputy Under Secretaries and Chiefs); 2016 Apr 13; Washington, DC.
Conference Presentations

  1. Lederer (Batki) S, Fischer M, Huo Z, Suda KJ, Stroupe KT. Medication Burden and Safety in Veterans with Chronic Kidney Disease. Poster session presented at: American Society of Nephrology Annual Meeting; 2015 Nov 7; San Diego, CA.
  2. Raad JH, Hatch M, Hou Z, Suda KJ, Chun S, Smith BM, Stroupe KT. Quantifying Healthcare Utilization among Veterans with Spinal Cord Injury. Poster session presented at: American Congress of Rehabilitation Medicine Annual Meeting; 2015 Oct 21; Dallas, TX.
  3. Stroupe KT, Bailey LA, Gellad WF, Suda KJ, Huo Z, Martinez RM, Burk ML, Cunningham F, Smith BM. Veterans' pharmacy and healthcare utilization following implementation of the Medicare Part D pharmacy benefit. Poster session presented at: VA HSR&D / QUERI National Meeting; 2015 Jul 9; Philadelphia, PA.
  4. Suda KJ, Bailey LA, Smith BM, Gellad WF, Huo Z, Cunningham F, Burk M, Stroupe KT. Opioid use in Veterans eligible for VA and Medicare Part D and predictors for overlap within and among VA and Medicare Part D-reimbursed pharmacies. Poster session presented at: VA HSR&D / QUERI National Meeting; 2015 Jul 9; Philadelphia, PA.
  5. Stroupe KT, Bailey LA, Gellad WF, Suda KJ, Huo Z, Martinez RM, Burk M, Cunningham F, Smith BM. Veterans' Pharmacy Utilization following Implementation of the Medicare Part D Pharmacy Benefit. Poster session presented at: AcademyHealth Annual Research Meeting; 2015 Jun 15; Minneapolis, MN.
  6. Spencer S, Huo Z, Stroupe KT, Smith BM, Suda KJ. Erectile Dysfunction Medication Use in Veterans Eligible for Medicare Part D. Poster session presented at: Illinois Council of Health-System Pharmacists Annual Spring Meeting; 2015 Mar 20; St. Charles, MO.
  7. Smith BM, Stroupe KT, Bailey LA, Rogers T, Huo Z, Martinez RM. Enrollment of Veterans in Medicare Part D. Poster session presented at: AcademyHealth Annual Research Meeting; 2014 Jun 8; San Diego, CA.
  8. Stroupe KT, Smith BM, Bailey LA, Rogers T, Huo Z, Martinez RM. Healthcare utilization of VA and Medicare-covered Services following implementation of the Medicare Part D Drug Benefit. Poster session presented at: AcademyHealth Annual Research Meeting; 2014 Jun 8; San Diego, CA.


DRA: Health Systems
DRE: Treatment - Observational, Treatment - Comparative Effectiveness
Keywords: Cost-Effectiveness, Efficiency, Policy - VA or other
MeSH Terms: none