Medication Days’ Supply, Adherence, Wastage, and Cost Among Chronic Patients in Medicaid

Abstract

Background:In an attempt to contain Medicaid pharmacy costs, nearly all states impose dispensing limits on medication days' supply. Although longer days' supply appears to increase the potential for medication wastage, previous studies suggest that it may also decrease pharmacy expenditures by reducing dispensing fees and drug ingredient costs. This study was conducted to determine whether 90-day refills at community pharmacies could improve adherence, minimize wastage, and control costs.Methods: This retrospective observational study used California Medicaid claims, from the Walgreens pharmacy chain dated January 2010, to identify 52,898 patients prescribed statin, antihypertensive, selective serotonin reuptake inhibitor (SSRI), or oral hypoglycemic medications. Adherence was measured by medication possession ratio (MPR) and persistency with a 30-day gap. Medication wastage was defined as a switch of drug or drug strength within the same therapeutic class that occurred before the expected refill date.Results: Adherence was 20% higher and persistency was 23% higher for the 90-day group than the 30-day group. This amounted to an average increase of 0.14 MPR and 44 days of continuous therapy. The two groups had comparable proportions of patients with wastage. After subtracting an average wastage cost of $7.34 per person per year (PPPY), all therapeutic classes had PPPY savings: statins ($7.70), antihypertensives ($10.80), SSRIs ($18.52), and oral hypoglycemics ($26.86). Conclusion:Across four drug categories and compared to 30-day refills, patients with 90-day refills had greater medication adherence, greater persistency, nominal wastage, and greater savings.

Clinical effectiveness and cost-effectiveness of issuing longer versus shorter duration (3-month vs. 28-day) prescriptions in patients with chronic conditions: systematic review and economic modelling

“…42 Half of the studies specified the insurance scheme that patients were enrolled in: two (US) studies included predominantly indigent populations (adults who do not have health insurance and are not eligible for Medicaid, Medicare or private health insurance), 39,43 two studies were conducted among Medicaid patients, 44,45 four studies were set in Veterans Health Administrations 37,40,42,46 and one study used data from Kaiser Permanente health-care delivery sites. 47 All of the studies were conducted in the USA.…”

“…Nine of the 16 studies compared a 30-day medication supply with a 90-day supply 32,35,36,41,42,45,46,48,49 and three studies compared three lengths of supply: 30 days, 31-89 days and ≥ 90 days. 38,40,47 The remaining four studies considered (1) 30 days' versus 60 days' supply, 39 (2) 100 days' versus 34 days' supply, 44 (3) 90 days versus < 90 days' supply 37 and (4) prescription lengths of ≤ 90 days.…”

“…43 The number of medications examined in a single study ranged from one 40 to 'any medication for a chronic condition'. 49 The most common clinical classes evaluated were lipid-lowering agents, The study periods ranged from 3 months 46 to 7 years; 37 only one study was conducted over a period of less than 1 year, 46 six studies were conducted over a 12-month period 32,36,42,43,45,47 and eight studies were conducted over a period of more than 1 year. 35,37,[39][40][41]44,48,49 Ryvkin et al 38 did not report the length of their study.…”

“…35,37,[39][40][41]44,48,49 Ryvkin et al 38 did not report the length of their study. The most common outcomes measured were adherence, 35,36,39,40,[43][44][45]47 wastage 32,36,38,41,42,45,46,48 and costs. 42,[44][45][46]49 When the study design was not reported 35,36,38,43,46 or was unclear, 41,49 the design was classified by three reviewers (JE, SK and CMiani) based on the information presented, and guided by the NICE algorithm for classifying quantitative study designs.…”

“…Of the 16 included studies, nine were retrospective cohorts (six described as such by the study authors 32,37,39,40,45,48 and three classified as such by the reviewers 35,36,38 ), two were retrospective pre-post studies (one so described by the authors, 44 the other defined as such by the reviewers 41 ), three were cross-sectional studies (two described as such by the authors, 42,47 the other so defined by the reviewers 43 ) and two were cost analyses (both defined as such by the reviewers). 46,49 In addition, the authors of one of the retrospective cohort studies 45 and of one of the retrospective pre-post studies 44 undertook a cost-consequences analysis. In the vast majority of the studies, the authors undertook a secondary data analysis of pharmacy claims data.…”