The need for an iterative process for assessing economic outcomes associated with SSRIs

Diagnosis of depression and use of antidepressant pharmacotherapy among adults in the United States: does a disparity persist by ethnicity/race?

BACKGROUND AND OBJECTIVE

Both the rate of diagnosis of depression in the US and the rate of prescribing an antidepressant for its treatment have increased substantially over the past two decades. Previous research has also indicated that the rates of diagnosis and treatment of depression with an antidepressant vary widely by ethnicity/race. The objective of this study was to discern ethnic/race-specific (non-Hispanic Black; Hispanic; non-Hispanic White) population-adjusted rates of US office-based physician-patient encounters (office-based visits) documenting a diagnosis of depression, and the extent of the use of antidepressant pharmacotherapy for its treatment.

METHODS

Data from the US National Ambulatory Medical Care Survey (NAMCS) for the years 1992-1997 and 2003-2008 were utilized for this analysis. The years 1998-2002 were excluded due to the magnitude of missing data for the variable ethnicity. The US NAMCS is a national probability sample designed and conducted by the US National Center for Health Statistics of the US Centers for Disease Control and Prevention. Depression was defined via International Classification of Diseases, 9th Revision, Clinical Modification codes 296.2-296.36; 300.4; 311. Antidepressants were defined as US National Drug Code category 0630 prior to 2005, and category 249 in Lexicon Plus® thereafter. Data were partitioned into six 2-year time intervals for trend analysis of population-adjusted rates (per 100) among patients aged 20-79 years. Rates per 2-year time interval are based on US Census Bureau national resident population estimates for the ethnicity/race categories examined. Comparisons within and across time-frames were assessed by chi-squared (χ2) analysis. The a priori level of significance for all statistical tests was set at p < 0.05. Analyses were performed using SAS Release 9.1.3.

RESULTS

Over the 12-year time-frame examined, the rate of office-based visits documenting a diagnosis of depression increased 28.4% for non-Hispanic Whites (from 10.9 to 14.0 per 100; p < 0.001), 54.8% for non-Hispanic Blacks (from 4.2 to 6.5 per 100; p < 0.001), and 37.5% for Hispanics (from 4.8 to 6.6 per 100; p < 0.001). The rate of office-based visits with a recorded diagnosis of depression in concert with the prescribing of an antidepressant increased 66.2% for non-Hispanic Whites (from 6.5 to 10.8 per 100; p < 0.001), 69.2% for non-Hispanic Blacks (from 2.6 to 4.4 per 100; p < 0.001), and 36.7% for Hispanics (from 3.0 to 4.1 per 100; p < 0.001).

CONCLUSION

By 2003-2004, the population-adjusted rates for non-Hispanic Blacks and Hispanics were similar, and remained so through 2007-2008. However, over the 12-year time-frame examined, the rates for both minority groups were, in each 2-year interval, far less than that observed in non-Hispanic Whites. Disparities remain by ethnicity/race in the diagnosis and treatment of depression in the US.

Ethnicity/race and the diagnosis of depression and use of antidepressants by adults in the United States

The objective of this study is to discern ethnic/race-specific (black, Hispanic, white) population-adjusted rates of US office-based visits documenting a diagnosis of depression, and the extent of the use of antidepressant pharmacotherapy for its treatment. Data from the National Ambulatory Medical Care Survey for the time-frames 1992-1997, and 2003-2004, were partitioned into four, 2-year time intervals for trend analysis among patients aged 20-79 years. From 1992-1993 to 2003-2004, the annualized rate of visits documenting a diagnosis of depression increased from 10.9 to 15.4 per 100 US population for whites, from 4.2 to 7.6 for blacks, and from 4.8 to 7.0 for Hispanics. A concomitant diagnosis of depression and antidepressant use increased from 6.5 to 11.4 per 100 for whites, from 2.6 to 5.2 for blacks, and from 3.0 to 5.6 for Hispanics. It can be concluded that by 2003-2004, diagnostic and treatment rates were comparable among blacks and Hispanic, but were less than half the observed rates for whites.

Pharmacoeconomic evaluation of antidepressants : a critical appraisal of methods

In recent years, there has been much debate regarding the real cost effectiveness of new antidepressants. This review is an attempt to identify key contentious methodological issues that can impact the reliability, validity and quality of the research on this subject. There are inherent complexities between inputs and outcomes related to depression, and the choice of pharmacoeconomic methodology requires a crucial balance between the study design and its ability to capture relevant information. Knowledge of the real efficiency of antidepressants should always be ascertained with reference to the real-world setting. Studies that show a corresponding balance between internal and external validity, coupled with sound methodology and standardised reporting, have the potential to translate pharmacoeconomics research into real-world, time-relevant decision-making.

Considerations in the treatment of anxiety disorders: a pharmacoeconomic review

Anxiety disorders are a group of common mental disorders that impose a significant economic burden on the healthcare system and society. For this review of published literature on the pharmacoeconomics of treating anxiety disorders, various studies of the cost, resource use and the economic outcomes of pharmacological treatment were examined. Numerous studies have been published that document how the excessive costs associated with anxiety disorders, especially panic disorder, result from a combination of factors including under-recognition and misdiagnosis of the problem by primary healthcare providers, high medical resource utilisation including unnecessary or inappropriate diagnostic tests and high levels of medical help-seeking behaviour by patients. Little information has been available on the economic effects of pharmacotherapy for anxiety disorders but recent studies have shown that selective serotonin re-uptake inhibitors (SSRIs) are associated with a shift in medical resource utilisation (lower rates of emergency department and laboratory visits) which can potentially result in decreased healthcare expenditures. Facilitating an increased awareness among primary healthcare providers of the anxiety disorders and utilising appropriate diagnostic and treatment strategies can benefit patients while providing more efficient and effective healthcare spending leading to an overall reduction in the burden of disease.

Using forecasting models to estimate the effects of changes in the composition of claims for selective serotonin reuptake inhibitors on expenditures

BACKGROUND

The use of selective serotonin reuptake inhibitors (SSRIs) as antidepressant therapy has increased considerably since the introduction of fluoxetine in 1989. By 1999, 3 of the 4 available SSRIs were among the top 10 most frequently used drugs in the United States. In addition, SSRIs were one of the major contributors to the growth in psychotropic medication expenditures during the past 5 years.

OBJECTIVE

The purpose of this article was to examine the utilization patterns of the 4 most commonly used SSRIs and their contribution to rising antidepressant medication expenditures among claimants in a publicly funded drug program. Using the results of forecasting models, we explored possible ways to control these growing expenditures.

METHODS

Cross-sectional antidepressant claims and expenditure data from the Ontario Drug Benefits program for 1992 to 1998 were examined. Five scenarios were modeled in which future SSRI expenditures and claims were predicted using exponential smoothing models.

RESULTS

If the historical patterns of use continued, a 20% increase in the 1998 level of expenditures was expected to occur by the year 2000. Predicted expenditures are sensitive to the composition of the SSRI claims. Exclusive use of 1 of the 4 major SSRIs (fluvoxamine, fluoxetine, paroxetine, and sertraline) could decrease projected expenditures by 30% or increase them by 11%. An "equal shares" approach, in which each of the 4 SSRIs are used in equal proportions in the population, may reduce expenditures by approximately 8%.

CONCLUSIONS

The current trends in the utilization data suggest that sertraline and paroxetine are being used as first-line treatments. The results of the forecasting models suggest that growing expenditures could be curbed if these 2 antidepressants were not used in that manner. Short of limiting the drugs available on benefit formularies, there may be a way to control costs through the use of a prescribing algorithm. Although our results support the use of fluoxetine for first-line SSRI treatment as a cost-control measure, we do not definitively recommend its adoption. These findings contribute to the discussion about using fixed versus flexible formularies as a potential cost-control mechanism.