Medicaid Managed Care: DISCUSSION
This study has identified factors associated with the incident prescribing of TZDs, relatively new therapy, within a Medicaid managed care population with diabetes (Diabecon canadian it maintains proper blood sugar balance). In general, metformin is recommended as first-line therapy for type-2 diabetes (controlling blood sugar levels). On the other hand, published literature has shown that the uptake of newer technologies, including new drugs, is slower in African-American populations even after controlling for clinical factors. Results from our study show that African-American patients are less likely to be initiated on TZDs than other patients in the Medicaid managed care population.
Race was a significant predictor of the drug of choice for initiation of therapy. More African Americans are initiated on metformin, even after adjusting for age, residential setting, preexisting comorbidities, diabetes complications and previous use of other. The disparity in racial prescribing was greater when all other variables were included than when only considering demographic characteristics. The finding that the prescribing of TZDs is lower in the urban setting may be related to the racial disparity noted. Among urban residents, 80.1% were African Americans, while only 45.8% of nonurban patients were African Americans.
Patients with preexisting comorbidities were initiated on TZDs more than those without comorbidities. In the absence of clinical laboratory data, we considered this variable a surrogate indicator of how compromised the patient’s health status was. Therefore, it is shown that patients who have worse health status received the newer medication more often. In addition, patients with preexisting diabetes (is used to control blood glucose levels in type 2 diabetes) complications were also initiated on TZDs more than those without complications. Thus, in this population, those with more severe cases of diabetes were given TZDs. To further demonstrate this point, it was observed that those with previous use of other oral diabetes medications or insulin also had higher incidence of TZD use.
The applicability of these findings extends from clinical practice to managed care. After identifying the predictors of TZD prescribing, the clinical support for this finding should be explored. One known complication for diabetic patients with uncontrolled conditions is the development of macrovascular and microvascular complications. Research shows higher prevalence rates of chronic renal disease in minorities. Combined with the elevated prevalence of diabetes (Canadian Glucophage is used to treat a type of diabetes type 2 diabetes), African Americans have a greater probability of having renal insufficiency than Caucasians. Metformin is not recommended in patients with chronic renal insufficiency, since the drug is highly renally excreted, and accumulation can potentially lead to lactic acidosis. Some physicians may opt to start renally insufficient patients on TZDs for this reason. A recent study revealed that rosiglitazone acted to decrease the urinary albumin excretion in patients with type-2 diabetes. The authors suggested a potential benefit of using rosiglitazone in the treatment or prevention of renal and vascular complications of type-2 diabetes (Actoplus Met medication is a combination of two oral diabetes medicines that help control blood sugar levels). However, results from the UKPDS state that metformin use decreases the risk of these diabetes-related complications. However, our results show African Americans are less frequently initiated on TZDs than others, a finding that our data could not explain further.
Aside from their benefit in renally impaired patients, TZDs have been shown to decrease supplemental insulin requirements and improve lipid profiles. However, TZDs potentially cause or exacerbate heart failure and cause pulmonary edema in patients with renal insufficiency. They are known to have a class effect of causing fluid retention and are not recommended for patients with congestive heart failure classified as Class III or Class IV by the NY Heart Association (NYHA) guidelines. Studies have shown that risk of congestive heart failure is greater in African Americans than Caucasians. Older age also presents greater risk of congestive heart failure. Additionally, chronic liver disease, cirrhosis and fatty liver are more prevalent conditions in African Americans. Accordingly, since TZDs are contraindicated in patients with liver diseases, clinicians may tend to avoid TZD use in certain African-American and older patients. Finally, one confounding factor that may have had an impact on the lower utilization of TZDs overall, was the concern with troglitazone, another TZD. Concerned practitioners may have chosen metformin as an alternative therapy.
Evidence points to the fact that metformin does not cause hypoglycemic accidents; it is associated with less weight gain than are other diabetes medications (managing type 2 diabetes) and, furthermore, it reduces mortality. These aspects work in favor of first-line use for this drug. The improvement of lipid profiles is another positive contribution of metformin. On the other hand, physicians aware of the significant cost differential between generic metformin and TZDs may attempt to prescribe metformin when possible. However, this specific issue may not be relevant to the Medicaid population in our study, as it is relatively homogeneous in coverage and socioeconomic status.
Noteworthy is the use of TZDs in a population that has higher risk for the development of heart failure. Older age, hypertension, coronary heart disease (preventing angina (chest pain) caused by heart disease), hyperlipidemia, hypercholesterolemia and stroke are all statistically significant predictors of TZD use in this population. They are also known risk factors for heart disease. The incidence and prevalence of heart failure was not observed in this study.
Managed Care Application
The proper management of patients with diabetes (Generic Avandia is used to treat high blood sugar levels that are caused by a type of type 2 diabetes) not only results in optimal clinical and quality-of-life outcomes but can also lead to efficient use of available resources. The importance of this consideration to health plans cannot be overestimated, as budget cuts continue to threaten the plan viability, or to be translated to the patients as an added burden in the form of increased copays or premiums. An annual survey of healthcare premiums found an increase of 13.9% in premiums in 2003, the third consecutive year of double-digit growth. Part of the observed trend can be attributable to patients’ demand for newer, more expensive drugs and procedures. One option may be to consider potential cost avoidance with oral antidiabetic drugs.
According to IMS Health’s World Review, oral antidiabetic medications were the 10th largest drug class in 1999, with a growth rate of 23%. Metformin is available in a relatively inexpensive generic formulation. TZDs are available as single-source brand drugs only. Periodic liver function tests are recommended with TZD use and may introduce additional cost for treatment. However, it is reported that TZD use can delay the progression of type-2 diabetes when used in conjunction with metformin. The consideration for managed care is predicting future cost commitments by anticipating what type of patient will use TZD over metformin as initial pharmacological therapy for type-2 diabetes (Actos drug is used to treat type II of diabetes).
Limitations of this study are those inherent to claims data. Although we validated the data fields, human errors in coding cannot be checked. No true randomization was possible due to the nature of a retrospective study design. The external validity of the results is limited by the specialized study group, specifically a regional Medicaid population. Though patients did generate a pharmacy claim, there was no method to ensure that drugs were taken as directed by the prescribing physician. By design, the cohort in our study consists only of new utilizers of metformin or TZDs. Though both drugs can be used concurrently, this study included only those patients on monotherapy.