Access and Utilization of New Antidepressant and Antipsychotic Medications

The truest measure of access to and utilization of pharmaceuticals is analysis of actual patterns of claims processed for individual drugs. Although analysis of these patterns across all health care payers is outside the scope of this research, this section analyzes trends in utilization of antidepressants and antipsychotics in Medicaid between 1995 and 1998.

In brief, this analysis found:

Antidepressants and antipsychotics account for a large proportion of Medicaid pharmaceutical prescriptions and reimbursements. The impact of newer antidepressants and antipsychotics on expenditures is out of proportion to the number of prescriptions for these agents.

• In 1998, antidepressants and antipsychotics accounted for 9% of Medicaid prescriptions but 19% of Medicaid drug expenditures.
• Although the total number of prescriptions reimbursed by Medicaid has remained relatively constant between 1995 and 1998, expenditures have increased by over 40%.
• The growth rate in both number of prescriptions for and cost of antidepressants and antipsychotics outpaces that observed in Medicaid pharmacy benefits as a whole by more than 2-fold.

The volume of Medicaid antidepressant and antipsychotic prescriptions grew dramatically between 1995 and 1998.

• Medicaid antipsychotic prescriptions increased nearly 20% between 1995 and 1998.
  • Antipsychotic prescriptions totaled 9.1 million in 1995.
  • Antipsychotic prescriptions totaled 11 million in 1998.
• Medicaid antidepressant prescriptions grew by over 40% between 1995 and 1998.
  • Antidepressant prescriptions totaled 13.6 million in 1995.
  • Antidepressant prescriptions totaled 19 million in 1998.

Total expenditures by Medicaid programs for antidepressants and antipsychotics grew dramatically between 1995 and 1998.

• Medicaid antipsychotic expenditures increased nearly 160% between 1995 and 1998.
  • Antipsychotic expenditures totaled $484 million in 1995.
  • Antipsychotic expenditures totaled $1.3 billion in 1998.
• Medicaid antidepressant expenditures grew by over 96% between 1995 and 1998.
  • Antidepressant expenditures totaled $592 million in 1995.
  • Antidepressant expenditures totaled $985 million in 1998.

New generation antipsychotics been accepted into common use within Medicaid programs.

• In 1998, 51% of the 11 million prescriptions for antipsychotics were for atypical antipsychotics. Three 2^nd generation atypicals were available in 1998.
  • In contrast, atypicals accounted for only 17.5% of 9.1 million Medicaid antipsychotic prescriptions in 1995. Only one 2^nd generation atypical was available in 1995 (risperidone).
    • The use of atypical antipsychotics in Medicaid has more than doubled since 1995.
    • Concomitantly, the use of typical antipsychotics in Medicaid has dropped by 25% since 1995.

New generation antipsychotics have not simply supplanted typical antipsychotics. Rather the total market for antipsychotics in Medicaid has grown since their introduction. Increased use of atypical antipsychotics has driven expenditures.

New generation antidepressants have been accepted into common use in Medicaid.

• In 1998, 62% of the 19 million Medicaid antidepressant prescriptions were for new-generation, branded antidepressants.
  • In contrast, new generation antidepressants accounted for from 44% of 13.6 million Medicaid antidepressant prescriptions in 1995.
    • The market share of new generation antidepressants has grown by approximately 50% since 1995.
    • Concomitantly, the market share of TCAs in Medicaid has decreased by nearly 50%.
• The selective serotonin reuptake inhibitors (SSRIs) comprised 46% of total antidepressant prescriptions in 1998.
  • Prescriptions for the three leading agents (fluoxetine, paroxetine, and sertraline) were nearly equal with approximately 3 million prescriptions each, or a 15-16% share each.
• Tricyclic antidepressants accounted for 27% of total prescriptions in 1998.

Increased Medicaid expenditures for antidepressants have been driven both by uptake of new generation, branded agents and increased prescription volume.

• Much of this increase can be attributed to the steady, yet significant rise of the three leading SSRI antidepressants (fluoxetine, sertraline, and paroxetine).
  • Together, spending for fluoxetine, sertraline and paroxetine comprised over 70% of all Medicaid spending on antidepressant drugs in 1998 ($711 million).
• TCAs accounted for only 5% of all Medicaid dollars reimbursed for antidepressants ($54 million).

New generation antidepressants have not simply supplanted tradition antidepressants. Rather the total market for antidepressants in Medicaid has grown since their introduction.

Utilization of new-generation antidepressants and antipsychotics varies among the states. Not all states have adopted new-generation agents as quickly as others.

New-generation antidepressants and antipsychotics have been accepted into common use by Medicaid programs at about the same rate and to the same extent as other innovator drugs.

• Newer antipsychotics appear to be proportionally more expensive than other new generation pharmaceuticals such as oral antidiabetics.
• Newer antidepressants appear to be roughly equivalent in cost to these other classes.

A. Methodology

Quarterly, state level data on prescription drug utilization are available from the Health Care Financing Administration(now known as Centers for Medicare and Medicaid Services(CMS)) (HCFA(now known as CMS)). These data are reported at the National Drug Code (NDC) level. These data include all pharmaceuticals reimbursed through State Medicaid pharmacy programs. However, these data exclude prescriptions dispensed to Medicaid recipients enrolled in managed care plans where pharmacy benefits are included in the capitation arrangement. Therefore these data will miss drug utilization within those plans. As most Medicaid Managed Care plans are limited to the AFDC or TANF populations, therefore, one would expect that this deficiency would affect the analysis of antidepressant utilization more than it would antipsychotic utilization.

While these data are representative of the US Medicaid population, state-level analyses are difficult in some States due to missing data. Arizona and Tennessee fail to report Medicaid drug utilization data at all while Texas has not reported since the second quarter of 1995, and Colorado has not reported since the fourth quarter of 1996. Connecticut reported no data for 1998. Other States with questionable data include Indiana, Kansas, and Wyoming (1995 and 1996 data appear to be off by a factor of 10).

A total of 19 States report data for all 16 quarters of 1995-1998. Data imputation was accomplished for 13 other States using a linear or exponential growth interpolation model in Microsoft Excel. Missing data were imputed for States missing up to three quarters of data over the 1995-1997 period. Imputation of missing data allows analysis of data from 44 States and the District of Columbia (i.e., "45 States"). Data from Connecticut is included for years 1995-1997, but not 1998. Based on information from HCFA(now known as CMS) form 2082 (1998), these 46 States accounted for over 80% of Medicaid recipients in 1998. Only Arizona, Tennessee, Texas, Colorado, Kansas, and Indiana are excluded because of missing or suspect data.

Because the Medicaid data do not report diagnosis or dosage associated with each prescription, we were unable to analyze use of antidepressants and antipsychotics as a function of disease treated. Rather, we summarize all Medicaid use of these agents regardless of diagnosis. It should be emphasized that these data, therefore, include the use of antidepressants and antipsychotics for the treatment of illnesses other than schizophrenia or major depressive disorder. For antipsychotics, these illnesses may include behavioral disturbances in various forms of dementia as well as treatment-refractory depression and bi-polar illness. Antidepressants may be used to treat Obsessive-Compulsive Disorder, Attention Deficit Disorder, Generalized Anxiety Disorder, Bulimia, chronic pain, and sleeplessness to name a few.

In the following discussion, the word "prescription" should be understood to refer to, on average, a month's supply of medication. Using this definition requires claims data for clozapine to be divided by a factor of 4.3 to achieve comparability to prescriptions for other agents (this method accounts for Federal supply limitations of 7 days).

The monetary figures quoted for drug expenditures are net of rebate (i.e., the rebate amount returned to the State Medicaid agencies, as required by OBRA 1990, has been factored out of the expenditure data). As a result, Medicaid reimbursements represent a lower bound estimate of actual costs.

B. Trends in Medicaid Pharmaceutical Coverage

Total prescriptions in Medicaid were relatively flat between 1995 and 1998. Medicaid programs reimbursed 327 million prescriptions in 1995 and 331 million prescriptions in 1998. During the same period, antipsychotic prescriptions increased by nearly 20% while antidepressant prescriptions increased by just over 40%.

However, prescription expenditures increased by 43% between 1995 and 1998. Medicaid programs paid almost $8.9 billion for prescription drugs in 1995 and $12.8 billion in 1998. During the same period, expenditures on antipsychotics increased by approximately 160%, while prescriptions for antidepressants increased by 96%.

In 1998, the 11 million Medicaid antipsychotic prescriptions accounted for only 3% of all Medicaid prescriptions. However, the $1.3 billion spent for these pharmaceuticals represented nearly 11% of total expenditures. Similarly, the 19 million antidepressant prescriptions accounted for nearly 6% of total prescriptions, while the $985 million spent for these agents approached 8% of expenditures. Therefore, although antidepressants and antipsychotics account for nearly 9% of total Medicaid prescriptions in 1998, their impact to total pharmaceutical costs is nearly twice as large as their market share.

C. Utilization of Antipsychotics in Medicaid, 1995-1998

The American Hospital Formulary lists nearly twenty different agents that are classified as antipsychotics. Most of these belong to the general class of phenothiazine derivatives. For the purposes of this analysis, antipsychotic medications were grouped into 8 general categories as indicated in Exhibit VI-1 below.

1. In 1998, 51% of All Medicaid Prescriptions for Antipsychotics were for Atypical Antipsychotics. Expenditures on Atypicals Accounted for 89% of Total Spending on Antipsychotics

   In 1998, Medicaid programs in the 45 States analyzed paid for nearly 11 million prescriptions for antipsychotics. Exhibit VI-2 shows the market share in Medicaid for each class of antipsychotic in 1998. Phenothiazines accounted for the largest share of antipsychotic prescriptions, with approximately 3.0 million prescriptions, or a 26% share. Risperidone ranked second in number of prescriptions (2.8 million, 25%) followed by olanzapine (2.2 million, 20%), and haloperidol (1.6 million, 15%). Clozapine prescriptions accounted for 4% of total prescriptions (442,000 prescriptions). Quetiapine logged only 174,000 prescriptions in its first full year on the market (2%), slightly less than the number of prescriptions for injectable haloperidol (185,666, 2% share). As a group, atypical antipsychotics accounted for just over 53% of all prescriptions for antipsychotics in 1998 (4.6 million).

In dollar terms, these 11 million prescriptions corresponded to expenditures of $1.3 billion. As seen in Exhibit VI-3, olanzapine accounted for the largest share of spending for antipsychotics at $536 million (42%). Risperidone ranked second at $395 million (31%), followed by clozapine at $172 million (14%). Oral haloperidol and phenothiazines accounted for only 2% ($12.3 million) and 6% ($75.6 million) of expenditures, respectively. Quetiapine accounted for 2% of total antipsychotic expenditures ($24 million). Atypical antipsychotics account for the vast majority of expenditures on antipsychotics: in 1998, just over $1.1 billion, or 89% of expenditures.

Oral formulations comprise the vast majority of the outpatient Medicaid market. Injectable haloperidol accounted for 2% of prescriptions (185,666) and 2% of expenditures ($27.6 million) in 1998.

Exhibit VI-4 presents the data in Exhibits VI-2 and VI-3 in tabular format.

2. The Use of Atypical Antipsychotics In Medicaid Has Grown Dramatically Since 1995

   Exhibit VI-5 depicts national trends in prescriptions for antipsychotics in Medicaid between 1995 and 1998. Overall, antipsychotic prescriptions rose from 9.2 million in 1995 to 11 million in 1998, an increase of nearly 20%. At the same time, total expenditures increased from $484 million in 1995, to $894 million in 1997 and $1.3 billion in 1998, an overall increase of 160% (Exhibit VI-6).

   This disproportionate growth in expenditures as compared to prescriptions has been driven by the rapid uptake of newer agents. The data in Exhibit VI-7 also show that since the introduction of risperidone in 1994 and olanzapine in 4^th quarter of 1996, there have been steady increases in the number of prescriptions for these agents. These occurred alongside a concomitant decrease in the number of prescriptions for oral haloperidol and phenothiazines both in terms of total prescriptions and in terms of market share. Thus, it appears that the introduction of atypical antipsychotics did not merely replace older therapies, but instead expanded the market for use of these agents as a category.

   Exhibit VI-5. Antipsychotic Prescription Trends in Medicaid, 1995-1998
   
   Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1998, 45 States Reporting, 1998.
   Exhibit VI-6. Antipsychotic Prescription Trends in Medicaid, Total Expenditures, 1995-1998
   
   Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1997. 46 States reporting, 1995-1998, 45 States Reporting, 1998.

   As shown in Exhibit VI-7, Medicaid prescriptions for risperidone increased from just over 1 million in 1995 (12% of total) to nearly 2.8 million in 1997 (25% of total). Similarly, the diffusion of olanzapine has also been rapid: 43,000 prescriptions were paid for by Medicaid in 1996 (0.5%), while just over 2.1 million prescriptions were covered in 1998 (20%). In contrast, prescriptions for oral haloperidol decreased from 2.1 million in 1995 (23%) to 1.6 million in 1998 (18%), and prescriptions for phenothiazines decreased from 4.2 million in 1995 (47%) to just under 3 million in 1997 (27%).

   Clozapine prescriptions also increased between 1995 and 1997, but the rate of growth did not match that of risperidone and olanzapine. Medicaid paid for 506,000 prescriptions of clozapine in 1995 and 590,000 prescriptions in 1997, an increase of nearly 25%. Clozapine prescriptions as a percent of total, however, remained virtually constant at approximately 5.5% during this time period. Clozapine prescriptions dropped in 1998 to 442,000 (4%). This result is not surprising given that clozapine is used almost exclusively for treatment-refractory schizophrenia. The introduction of olanzapine in 1996 likely resulted in physicians moving clozapine to third-line therapy (after both risperidone and olanzapine) in difficult-to-treat patients, resulting in a reduction in the number of clozapine prescriptions. Similarly, use in injectable haloperidol prescriptions remained steady.

   Exhibit VI-7. Antipsychotic Prescription Trends in Medicaid by Class, 1995-1998
   
   Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 45 States reporting, 1995-1998, 46 States Reporting, 1998.

   In 1995, reimbursements for clozapine and risperidone each accounted for 33% of total antipsychotic expenditures (approximately $165 million each, see Exhibit VI-8). Reimbursements for phenothiazines accounted for an additional $101 million, or 20%. In 1996, Medicaid expenditures for risperidone reached $269 million (42%), while expenditures for clozapine increased only slightly to $198 million (31%). Phenothiazines accounted for an additional $103 million, or 16%. In 1998, risperidone expenditures reached $395 million (31%), while olanzapine reached $536 million in Medicaid reimbursements (42%). Spending for clozapine remained nearly constant in the range between $170 million and $192 million. By 1998, the $172 million spent on clozapine by these 45 programs represented only 14% of total expenditures for antipsychotics. This amount represents a smaller share of total spending than in previous years (e.g., in 1995, 21% of antipsychotic expenditures were for clozapine). Phenothiazines accounted for $76 million in 1998, or 6% of total spending.

   Exhibit VI-8. Antipsychotic Prescription Trends in Medicaid, Total Expenditures by Class, 1995-1998
   Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1997. 46 States reporting, 1995-1998, 45 States Reporting, 1998.

3. Patterns of Antipsychotic 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 were: California, Florida, Georgia, Illinois, Maryland, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, and Wisconsin, all of which are among those with the highest utilization and among 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-9 reports the volume of antipsychotic medications paid for under Medicaid in these twelve high-volume States, which account for 64% of prescription volume for antipsychotics reported by Medicaid programs in 1998. Moreover, the 12 States account for 67% of the total amount reimbursed for antipsychotics in 1998.

Exhibit VI-10 depicts the share of total antipsychotic utilization in each state for five categories of antipsychotics: clozapine, risperidone, olanzapine, oral haloperidol, phenothiazines, and quetiapine. In interpreting these data, it should be remembered that phenothiazine prescriptions might reflect use for other disorders.

The data in Exhibit VI-10 show:

• Phenothiazines were the most frequently prescribed antipsychotic in 5 States (California, Georgia, New Jersey, New York, Ohio).
  • Phenothiazines accounted for between 24% (several States) and 31% (CA) of prescriptions.
• Risperidone was the most frequently prescribed antipsychotic in 6 other States (Florida, Illinois, Massachusetts, Maryland, Michigan, Pennsylvania).
  • Risperidone accounted for between 19% (CA) and 30% (PA) of total scripts.
  • Medi-Cal lagged the rest of its peers in adoption of risperidone.
• In Wisconsin, there were roughly equal numbers of prescriptions for phenothiazines and risperidone in 1998.
• Olanzapine ranked third in total prescriptions in every state except for California, Massachusetts and Georgia. The share of prescriptions accounted for by olanzapine ranged from 14% (Georgia) to 26% (Massachusetts).
  • Olanzapine prescriptions outnumbered risperidone prescriptions in Medi-Cal in 1998 by 15,000.
  • In Massachusetts, olanzapine prescriptions equaled those for risperidone with 26% of the total each.
  • In Georgia olanzapine ranked fourth with only 14% share.
• Haloperidol ranked fourth in every state except Georgia, capturing between 14% and 19% of to prescriptions.
• Clozapine, generally reserved for treatment-refractory cases of schizophrenia, accounted for between 2% (Georgia) and 7% (Illinois, Michigan) of total antipsychotic prescriptions.
• Quetiapine gained no more than 3% market share in any state.

4. The Uptake of Newer Antipsychotic Agents into Medicaid Immediately Post-Launch has been Rapid

   Two antipsychotic agents have been launched in the last two years: olanzapine in the 4^th quarter of 1996 and quetiapine in the 4^th quarter of 1997. The rates of uptake of each of these two drugs illustrate many of the factors that affect the rate of uptake of a new antipsychotic agent.

   As shown in Exhibit VI-11, the rate of uptake of olanzapine has been remarkably fast. From launch in the 4^th quarter of 1996, olanzapine gained 8% market share within four full quarters. At the end of the second full year on the market, olanzapine attained a market share of 16% in the 45 Medicaid jurisdictions included in the analysis. This change represents a doubling of the number of prescriptions dispensed over the previous year. In contrast, quetiapine obtained only 4% market share within its first four quarters on the market, only half that of olanzapine.

   These results indicate that Medicaid has increasingly accepted atypical antipsychotics, and in recent years has done so rather quickly. These gains in market share for olanzapine and quetiapine occurred in a Medicaid market that was transitioning from typical to atypical antipsychotics. This trend is further evidenced by the fact that from the time of the launch of olanzapine, risperidone market share increased from 17% to 22%, while the number of risperidone prescriptions increased nearly 50%.

   There are likely many reasons for the slow uptake of quetiapine relative to olanzapine. First, the uptake of olanzapine was extremely fast by most standards. Furthermore, quetiapine was the third entrant in to the field of second generation, relatively undifferentiated atypical antipsychotics. As a result, clinicians may have been reluctant to learn to use a third new agent that did not offer any clear advantages over familiar therapies (i.e., risperidone, and olanzapine). Finally, the fact that the manufacturer of quetiapine, Zeneca (now AstraZeneca) was relatively inexperienced at marketing pharmaceuticals to the mental health services sector likely slowed diffusion of quetiapine even further.

D. Utilization of Antidepressants in Medicaid, 1995-1998

The American Hospital Formulary lists over 30 different agents that are classified as antidepressants. Most of these belong to the general class of tricyclic antidepressants. For the purposes of this analysis, antidepressant medications were grouped into 12 general categories as indicated in Exhibit VI-12 below.

1. In 1998, 62% of the 19 Million Medicaid Antidepressant Prescriptions were for New-Generation, Branded Antidepressants

   In 1998, Medicaid programs in these 45 States paid for over 19 million prescriptions for antidepressants. Exhibit VI-13 shows the market share in Medicaid for each class of antidepressant in 1998. The selective serotonin reuptake inhibitors (SSRIs) citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline comprised 48% of total antidepressant prescriptions in 1998. Prescriptions for the three leading agents (fluoxetine, paroxetine, and sertraline) were nearly equal with approximately 3 million prescriptions each, or a 15-16% share each. Tricyclic antidepressants accounted for 27% of total prescriptions, or approximately 5 million prescriptions. Trazodone, with 2.2 million prescriptions in 1998, took 12% of the market. The four other new generation antidepressants (bupropion, mirtazapine, nefazadone, and venlafaxine) together accounted for 14% of prescriptions or approximately 2.7 million prescriptions. In total, new generation antidepressants accounted for over 62% of all prescriptions in Medicaid in 1998.

   In dollar terms, these 19 million prescriptions corresponded to expenditures of nearly 1 billion dollars ($985 million). As seen in Exhibit VI-14, fluoxetine, while comprising only 15% of all Medicaid antidepressant prescriptions, accounted for 30% ($288 million) of all Medicaid spending for antidepressants in 1998 -- the highest among all antidepressants. The cost of fluoxetine is far greater than one would expect by making market share comparisons to similar agents. For example, sertraline accounted for more prescriptions in 1998 than fluoxetine, but spending for sertraline reached only $214 million (23% of all Medicaid dollars reimbursed for antidepressants in 1998). Similarly, dollars spent on paroxetine comprised only $199 million (20% of all Medicaid dollars spent on antidepressants in 1998) while the number of prescriptions was roughly equal to that of fluoxetine. Together, fluoxetine, sertraline and paroxetine comprised over 70% of all Medicaid spending on antidepressant drugs in 1998 ($711 million). While TCAs made up one-quarter of all prescriptions in 1998, they accounted for only 5% of all Medicaid dollars reimbursed for antidepressants ($54 million). The other new antidepressants bupropion, venlafaxine, nefazadone, and mirtazapine together accounted for expenditures of approximately $173 million or 18% of total expenditures, while capturing 14% of total prescriptions.

   The data in Exhibits VI-13 and VI-14 are depicted in tabular form in Exhibit VI-15.

2. The Use of New-Generation Antidepressants in Medicaid Grew Dramatically Between 1995 and 1998

   Exhibit VI-16 depicts national trends in prescriptions for antidepressants in Medicaid between 1995 and 1998. Overall, prescriptions for antidepressants increased substantially in this period. Antidepressant prescriptions increased from 13.7 million in 1995 to 19.3 million in 1998, an increase of over 40%. Exhibit VI-17 reports trends in Medicaid expenditures for antidepressants between 1995 and 1998. Total expenditures increased steadily from $500 million in 1995, to $630 million in 1996, to $760 million in 1997 and to $985 billion in 1998--an average increase of 25% per year, and an overall increase of 96%. Much of this increase can be attributed to the steady, yet significant rise of the three leading SSRI antidepressants.

   Prescriptions increased for every class of antidepressant except for TCAs and MAOIs. These trends are shown in Exhibit VI-18. Prescriptions for sertraline and fluoxetine increased by approximately 45% each, from already substantial bases in 1995. Sertraline prescriptions increased from just over 2 million in 1995 to just over 3 million in 1998. Fluoxetine prescriptions increased from just over 2 million in 1995 to just fewer than 3 million in 1998. Paroxetine prescriptions increased from 1.2 million in 1995 to 2.9 million in 1998, an increase of 130%. Fluvoxamine experienced more than a four-fold increase in prescriptions from 1995 to 1998 (72,885 to 306,967, an increase of 321%) while bupropion prescriptions increased 264%. Prescriptions for venlafaxine doubled over the same period. During the same period, prescriptions for TCAs fell from 6 million prescriptions in 1995 to 5 million in 1998.

Exhibit VI-13. Market Share of Antidepressant Classes in 45 Medicaid States, 1998. Total Prescriptions = 19 Million

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1998. 45 States Reporting.

Exhibit VI-14. Market Share of Antidepressant Classes in 45 State Medicaid Programs, 1998. Total Expenditures = $985 Million

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1998. 45 States Reporting.

Exhibit VI-15. Share of Medicaid Antidepressant Prescriptions and Expenditures by Class, 1998
	Prescriptions		Expenditures
Class	Number (000s)	% of Medicaid Antidepressant Rx's	$ (Millions)	% of Medicaid Antidepressant $
Fluoxetine	2953	15%	$288	29%
Fluvoxamine	307	2%	$34	3%
Paroxetine	2925	15%	$199	20%
Sertraline	3007	16%	$214	22%
Bupropion	1054	5%	$64	7%
Venlafaxine	663	3%	$45	5%
Nefazadone	697	4%	$33	3%
Mirtazapine	436	2%	$29	3%
Trazodone	2215	11%	$22	2%
MAOIs	18	0%	$1	0%
TCAs	5055	26%	$54	5%
All Antidepressants	19,354	100%	$985	100%
Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1998. 45 States Reporting.

Exhibit VI-16. Antidepressant Prescription Trends in Medicaid, 1995-1998. Total Prescriptions in Thousands

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1997, 45 States Reporting, 1998.

Exhibit VI-17.Antidepressant Prescription Trends in Medicaid, 1995-1998. Expenditures in Millions

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1997, 45 States Reporting, 1998.

The data in Exhibit VI-18 also show that since the introduction of nefazadone in 1995 and mirtazapine in 1996, there have been steady increases in the number of prescriptions for these agents. By the end of its second year on the market, nefazadone claimed 697,000 prescriptions, nearly 4% of the market, while mirtazapine claimed 436,000 prescriptions or almost 3%. In addition, in its first quarter on the market (Q4, 1998) citalopram accumulated 22,544 prescriptions. Industry reports have indicated that citalopram claimed 10% of the SSRI market by November 1999, making it the forth most successful pharmaceutical launch in history⁴³ It is unclear how citalopram has been received by Medicaid, however, as 1999 data was not available at the time of this study.

Exhibit VI-18. Antidepressant Class Prescription Trends in Medicaid 1995-1998. Total Prescriptions in Thousands

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1997, 45 States Reporting, 1998.

As shown in Exhibit VI-19, expenditures for paroxetine increased nearly three-fold (an increase of $128 million over four years), while expenditures for fluoxetine increased 73% ($120 million), and expenditures for sertraline increased 64% ($84 million). Expenditures for venlafaxine, bupropion, and nefazadone enjoyed large percentage increases over these years, but, as lower-volume antidepressants, the total reimbursed for these agents was not nearly as large as the total for the three leading agents. Expenditures for bupropion increased nearly 3-fold between 1997 and 1998, likely reflecting increased use of this agent as an aid to smoking cessation (a new indication for bupropion in 1997). In terms of dollars reimbursed, only TCAs fell significantly, from $77 million in 1995, to $67 million in 1996, to $54 million in 1997 and 1998.

As the total amount reimbursed for antidepressants increased steadily over this period, the market share of each of the antidepressant classes remained fairly constant during the years 1995 to 1998. With the largest share of the market, fluoxetine's share fell somewhat: from 33% in 1995 and 1996 to 32% in 1997 and to 29% in 1998. Likewise, sertraline, accounting for the second largest share of expenditures, also saw its share fall slightly, from 26% in 1995 to 22% in 1998. Expenditures for TCAs' fell as a percentage of total costs as well: from 15% in 1995 to 5% in 1998. Among the high-volume antidepressants, only paroxetine experienced an increase in terms of total share of Medicaid expenditures. Expenditures for paroxetine increased from 14% of total in 1995 to 20% in both 1997 and 1998. Bupropion, while beginning from a much lower dollar base in 1995, saw its Medicaid market share rise from 2% in 1995 to 6% in 1998.

Exhibit VI-19. Antidepressant Class Prescription Trends in Medicaid, 1995-1998. Total Expenditures in Millions

Source: The Lewin Group analysis of HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1997, 45 States Reporting, 1998.

• 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 (000s)	%	$ Amount (Millions)	%	Cost per Prescription
  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 SSRIs	Other New	All New	TCAs
  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.

  E. Comparison of Psychotherapeutic Utilization with Utilization of Other Drug Classes

  A primary concern of this study has been to determine whether newer psychotherapeutics are subject to more stringent utilization controls than are other classes of pharmaceuticals. In this section, we compare the utilization of psychotherapeutics with the utilization of other classes of pharmaceuticals that have seen the introduction of newer agents in recent years.

  The new oral antidiabetic agents make constitute an excellent comparator group to psychotherapeutics for a number of reasons:

  • Diabetes represents a major cost center for health care payers, as does mental health;
  • Pharmacotherapy for diabetes and mental illness is always a long-term commitment;
  • New pharmacologic agents, representing new mechanisms of action, entered a therapeutic area dominated by generics; and
  • These new antidiabetic agents were introduced during the same time period as the atypical antipsychotics (1994-1997).
  The oral antidiabetics included in this analysis are described in Exhibit VI-22, below.

  Exhibit VI-22. Oral Antidiabetic Categories
  Generic Name	Examples and Brand Names	Launch Date
  Acarbose	Precose®	1995
  Glimepiride	Amaryl®	1995
  Glipizide (extended release)	Glucotrol® XL	1994
  Metformin	Glucophage®	1995
  Repaglinide	Prandin®	4th quarter 1997
  Troglitazone	Rezulin®	1st quarter 1997
  Generic Sulfonyl Ureas (Representative) Acetohexamide Chlorpropamide Glipizide Glyburide	Dymelor® Diabinese® Gluotrol® DiaBeta®, Micronase®	Prior to 1995

  Medicaid prescriptions for oral antidiabetic agents increased from 4.1 million in 1995 to 7.6 million in 1998, an increase of 82%. At the same time, expenditures for these agents increased nearly 3-fold, increasing from $114 million in 1995 to $311 million in 1998.

  Proportionally, the increase in spending for oral antidiabetics was far smaller than the increase observed for the psychotherapeutic classes. Exhibit VI-23 shows the ratio between the percentage increase in expenditures and the percentage increase in total prescriptions between 1995 and 1998 for the three classes, antipsychotics, antidepressants, and oral antidiabetics. The results show that the ratio between the increase in expenditures and the increase in prescriptions is 8.0 for antipsychotics. (It should be remembered that clozapine prescriptions were relatively flat during this time, and therefore the increase in cost is largely attributable to other new agents.) For antidepressants this ratio is 2.4, whereas for oral antidiabetics this ratio is 2.1. These data show that the cost (in terms of pharmaceutical expenditures) of converting to newer agents is far greater for antipsychotics than it is for either antidepressants or oral antidiabetics. However, the cost for converting to newer antidepressants is only marginally greater than that for oral antidiabetics.

  Exhibit VI-23. Comparison of Increase in Prescriptions and Expenditures for 3 Pharmaceutical Classes in Medicaid, 1995-1998
  Class	% Increase in Prescriptions	% Increase in Expenditures	Ratio
  Antipsychotics	20%	160%	8.0
  Antidepressants	40%	96%	2.4
  Oral Antidiabetics	82%	172%	2.1
  Source: HCFA(now known as CMS) Medicaid Drug Rebate Program Data, 1995-1998. 46 States reporting, 1995-1998, 45 States Reporting, 1998.

  In spite of this difference in cost it appears that newer oral antidiabetics have replaced older agents only marginally faster than atypical antipsychotics have replaced traditional antipsychotics. In 1995, only 11% of all prescriptions for oral antidiabetics were for an agent other than a generic sulfonyl urea, by 1998, 55% of all prescriptions were for a newer agent. In contrast, whereas in 1995, only 16% of all antipsychotic prescriptions were for an atypical agent, in 1998, 51% of antipsychotic prescriptions were for an atypical antipsychotic.

   

  References

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  Chapter V

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  Chapter VII

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  Last updated August 20, 2000