Access and Utilization of New Antidepressant and Antipsychotic Medications. Patterns of Antidepressant Utilization in High-Volume States


Recognizing that national data may not be reflective of trends in individual States, utilization trends for 12 high-volume States (in number of prescriptions) in 1998 were analyzed in greater detail. The States included in this analysis are: California, Florida, Georgia, Illinois, Maryland, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, and Wisconsin. These States are among those both with the highest utilization and those interviewed for the present study. Texas, a state with a large Medicaid population and an interview subject for this study, is excluded because Texas Medicaid reported no pharmaceutical utilization data to HCFA(now known as CMS) in 1998.

Exhibit VI-20 reports the volume of antidepressant medications paid for under Medicaid in these 12 high-volume States. These 12 States alone comprise 58% of prescription volume and 59% of the total amount reimbursed for antidepressants reported by Medicaid programs in 1995-1998.

Exhibit VI-20. Number of Antidepressant Prescriptions and Total Amount of Medicaid Reimbursement for 12 High Volume States, 1995-1998

  Prescriptions Expenditures  
State Number
% $ Amount
% Cost per
CA 1,903 10% $260 10% $137
NY 1,733 9% $272 10% $157
OH 1,183 6% $159 6% $134
PA 988 5% $169 5% $171
MA 1,195 6% $172 6% $144
FL 977 5% $134 5% $137
IL 808 4% $108 4% $134
MI 601 3% $102 3% $170
GA 549 3% $74 3% $135
WI 489 3% $68 2% $139
NJ 415 2% $71 2% $171
MD 261 1% $38 1% $146
12-State Total 11,104 58% $1,629 59% $147
US Total 19,255 100% $2,726 100% $142

Source: HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1998, 45 States Reporting, 1998.

At first glance it would appear that there are some unexpected trends in the data. For example, Massachusetts Medicaid, a relatively small state program, paid for more prescriptions than did programs in much larger States including Pennsylvania and Illinois. Similarly, Medi-Cal only covered marginally more prescriptions than did New York Medicaid, a program half its size.

These apparent anomalies likely reflect a variety of programmatic differences among the Medicaid programs in these states. Although a comprehensive analysis of these differences is beyond the scope of this study, we believe that factors that influence these differences include:

  • The population eligible for Medicaid and/or Medicaid Managed Care in each state;
  • The penetration of Managed Care into a State's Medicaid population; and
  • The financing arrangements for pharmaceutical coverage within states that have managed care programs (i.e., full capitation, partial capitation, or fee for service).

It is reasonable that managed care arrangements affect the utilization of pharmacy services for antidepressants more so than for antipsychotics. This is because whereas most persons with diagnoses of schizophrenia meet the criteria for classification as disabled, only a small portion of those with depression experience a severe enough episode to meet this designation. Most states exclude disabled persons from full capitation Medicaid Managed Care programs. Patients who use antidepressants may have a range of illnesses including depression, dysthymia, and anxiety disorders. The severity of these illnesses may cause a patient to become disabled. However, this is not usually the case. Therefore, many patients who at some time in their care require an antidepressant may be enrolled in a full-capitation Medicaid Managed Care program. As many of these programs have in the past covered prescription medications, prescriptions for these patients are effectively removed from the data reported to HCFA(now known as CMS).

Because of the difficulty in precisely determining the number of Medicaid eligibles who receive pharmaceutical benefits through their managed care plans, a more interesting measure of the utilization of antidepressants in Medicaid populations is the average cost per prescription. As shown in the final column of Exhibit VI-20, the cost per prescription ranges from a low of $134 per prescription in Ohio and Illinois, to a high of $171 in New Jersey and Pennsylvania. Other "low cost" States include Georgia ($135) and California ($137). Other high cost States include Michigan ($170). The difference in average prescription cost is not large and cannot by itself serve as an indicator of the utilization of newer or older agents.

Exhibit VI-21 depicts the share of total antidepressant utilization in each of the several classes of antidepressants: three high-volume SSRIs (fluoxetine, paroxetine, and sertraline), SSRIs as a class (including citalopram and fluvoxamine), the combined class of "other new antidepressants" (i.e., bupropion, mirtazapine, nefazadone, and venlafaxine) trazadone, and TCAs. MAOIs are excluded because they do not constitute a relevant percentage of the total. In brief, Exhibit VI-21 shows:

  • Utilization of all new-generation antidepressants ranges between a low of 51% in California to a high of 69% in New Jersey.
    • New generation antidepressants accounted for less than 65% of total prescriptions only in California (51%), Maryland (62%), and Illinois (58%).
  • SSRIs account for between 42% (California) and 53% (New Jersey) of total antidepressant prescriptions.
    • SSRIs account for 52% of prescriptions in Florida, Maryland, New York, and Pennsylvania.
  • The other new antidepressants account for between 9% (California) and 17% (Michigan, Massachusetts) of total prescriptions.
  • TCAs are the most commonly-prescribed antidepressants in California, where they account for 35% of all prescriptions, fully 5% greater market share than in the next highest state (Georgia, 30%). In other States, TCAs account for between 19% (Massachusetts) and 26% (Illinois).
  • Sertraline is the most commonly prescribed antidepressant in every state except for California, where it is not on formulary, and New York (where it is slightly outpaced by fluoxetine).
    • In these States, sertraline prescriptions account for between 16% and 19% of total prescriptions
    • In California sertraline prescriptions account for only 3% of prescriptions.
  • Paroxetine is the most commonly prescribed antidepressant in California, where it accounts for 20% of prescriptions.
  • Fluoxetine is the most-commonly prescribed in New York, where it accounts for 17% of total prescriptions.
    • Maryland has the lowest rate of prescribing for fluoxetine, where it accounts for only 13% of the market.

Exhibit VI-21. Market Share of Antidepressants in 12 High-Volume Medicaid States as Percent of Total Prescriptions, 1998

State Fluoxetine Paroxetine Sertraline All
CA 18% 20% 3% 42% 9% 51% 35%
NY 17% 17% 17% 52% 16% 68% 23%
IL 16% 13% 16% 46% 12% 58% 30%
OH 15% 14% 19% 49% 16% 65% 26%
FL 16% 14% 17% 48% 17% 65% 19%
MA 15% 16% 19% 52% 13% 65% 22%
PA 16% 14% 19% 50% 17% 67% 23%
NJ 14% 18% 19% 53% 16% 69% 22%
MI 17% 16% 17% 52% 14% 66% 25%
WI 15% 14% 19% 50% 16% 66% 22%
GA 16% 15% 19% 52% 16% 68% 21%
MD 13% 15% 18% 48% 14% 62% 25%

Source: HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1998. 46 States reporting, 1995-1998, 45 States Reporting, 1998.