Diabetes ambulatory care-sensitive hospitalizations, care organization, and medication adherence.

摘要

A retrospective cohort analysis using Indiana Medicaid claims, enrollment, and encounter data was conducted to determine the number and rate of ambulatory care sensitive conditions hospitalizations (ACSCH) that reflect quality of ambulatory diabetes care. ACSCH were identified based on the Agency for Healthcare Research and Quality Prevention Quality Indicators for diabetes short-term complications, uncontrolled diabetes, long-term complications and amputations. Association between care organization under Medicaid and likelihood of having an ACSCH, and association between adherence to oral diabetes medications and likelihood of having an ACSCH were assessed. Sample inclusion criteria were being age 18 years or older, diabetes diagnosis prior to January 2009, and continuous eligibility in 2008. Exclusion criteria were a nursing home stay, no claims, or death in 2008. Each individual was placed in one of four groups, one group each for those continuously in fee-for-service, care management, or managed care, and one group for those who switched care organization in 2008. A sample of 47,443 persons, with mean age of 53 years, 68% female and, 77% white was identified. Overall, there were 1,514 ACSCH, 31.91 (95% C. I.: 30.4 - 33.5) per 1,000 individuals with diabetes. Logistic regression assessed association between Medicaid sub-program and likelihood of ACSCH adjusting for age, gender, ethnicity, marital status, diabetes type, mental illness, hypertension, coronary artery disease, foot specific conditions and Charlson Comorbidity Index. Individuals in care management were more likely than those in fee-for-service to have ACSCH for short-term complications (OR=2.3, p=0.0001). Individuals in managed care were more likely than those in fee-for-service to have ACSCH for short-term complications (OR= 1.7, P= 0.015), but less likely to have ACSCH for uncontrolled diabetes (OR=0.3, p=0.045) or for long-term complications (OR=0.5, P=0.039). Persons who switched care organization were more likely to have ACSCH for short-term complications (OR=3.2, P=0.0001) and for amputations (OR=2.0, P=0.001). When overall total risk of any ACSCH regardless of type was examined, individuals that switched care organization had higher overall risk of non-cause specific ACSCH (OR=2.0, P=0.0001) than those in feefor- service and individuals in Hoosier Healthwise were less likely to have a non-cause specific ACSCH (OR=0.5, P=0.040) than those in fee-for-service. Examination of association between medication adherence and hospitalization for ACSCH was restricted to individuals 18 to 64 years old due to unavailability of Medicare Part D prescription claims for persons over 64 years old. Patients using insulin therapy also were excluded due to lack of a fixed regimen. A multivariate conditional logistic regression model was used to examine the association between medication adherence, based on proportion of days covered over 6 month and 12 month periods, and likelihood of having an ACSCH after adjusting for age, gender, ethnicity, marital status, mental illness, hypertension, coronary artery disease, foot specific conditions and Charlson comorbidity index. Individuals were classified as non-adherent to their medication regimens if proportion of days covered in the relevant interval was less than 80 percent. Based on 6-month adherence, there was no significant association between being classified as non-adherent in a 6-month interval and risk of hospitalization for ACSCH (OR = 1.93, P = 0.1099). However, analysis of 12-month adherence revealed that individuals who were nonadherent in a 12-month interval were significantly more likely than adherent individuals to have an ACSCH (OR = 4.45, P = 0.003). Transitions between Medicaid care organizations significantly influence likelihood of having an ACSCH. Continuity of care may be critical. Factors that may influence transitions or disruption of care may be identified that may provide useful information regarding the quality of care provided in this population. Care Coordination within Managed Care may be effective in individuals having a lesser likelihood of hospitalization for uncontrolled diabetes and long-term complications than Traditional Medicaid. Higher level of medication adherence was associated with lower likelihood of hospitalization for ACSCH. The findings add to the evidence that medication adherence is necessary to reduce the risk of hospitalizations for ACSCH. Future studies may focus on various interventions that can improve medication adherence for better patient outcomes. Moreover, reasons for medication non-adherence may be examined and strategies may need to be developed to improve access to medications for patients with diabetes.