economic evaluation of the use of oxybutynin, tolterodine and solifenacin in patients with...
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ECONOMIC EVALUATION OF THE USE OF OXYBUTYNIN, TOLTERODINE AND
SOLIFENACIN IN PATIENTS WITH OVERACTIVE BLADDER
February 6, 2009
Study type andanalysis method
• A complete cost-effectiveness economic evaluation was performed.
• This study was addressed from an institutional perspective in Public Health Institutions, particularly in IMSS (Mexico’s Social Security).
Comparators to manage Overactive Bladder in IMSS
4305 Oxybutynin TABLET, Each tablet contains: Oxybutynin chloride 5 mg.
Bottle with 30 tablets.$82.81 $248.43 $2,981.16
4304 TolterodineTABLET. Each tablet contains: Tolterodine L-tartrate 2.0
mg. Bottle with 14 tablets.$137.49 $589.24 $7,070.91
Pending Solifenacin***TABLET. Each Tablet contains Solifencin succinate 5 mg.
or 10 mg. Box with 10 tablets.$147.47 / $198.03 $442.41 / $594.09 $5,308.92 /$7,129.08
Cost/ Month Cost / Year
** Prices provided by Website of IMSS: "IMSS compro" from January - July 2008Source: *Dosage forms and prescritions reported in the Website of IMSS: "Cuadros Básicos de Medicamentos". December 2008
*** Price provided by Liomont Laboratory for the dosage form of Solifenacin 5 / 10 mg.
CB Code Drug Dosage Forms* Unitary Cost **
Direct Medical Costs
• Include the total costs related to the intervention as a whole,
• general costs to manage Overactive Bladder,
• costs of complications and adverse events.
Direct Medical Costs
• Direct Medical Costs
– Consultations (Files Review)– Clinical Tests (FR)– Imaging Examinations (FR)– Surgery (FR)– Adjuvant Medications (FR)
REF: File Review
• The usage function was built based on a review of files in two second-level medical care units of IMSS.
• The evaluation results were expressed in both, the average cost-effectiveness ratio, and in the incremental cost-effectiveness ratio.
Study type andanalysis method
• The evaluation will use the effectiveness data obtained from international literature, and especially from clinical trials, using an evidence-based medicine approach.
• A Markov model is the tool used to perform the cost-effectiveness analysis,
Study type andanalysis method
Markov ModelPatient without Incontinence
Patient without IncontinencePatient without Incontinence
Patient with Slight IncontinencePatient with Slight Incontinence
Patient with Moderate IncontinencePatient with Moderate Incontinence
Patient with Severe IncontinencePatient with Severe Incontinence
Patient with Slight Incontinence
Patient without IncontinencePatient without Incontinence
Patient with Slight IncontinencePatient with Slight Incontinence
Patient with Moderate IncontinencePatient with Moderate Incontinence
Patient with Severe IncontinencePatient with Severe Incontinence
Patient with Moderate Incontinence
Patient without IncontinencePatient without Incontinence
Patient with Slight IncontinencePatient with Slight Incontinence
Patient with Moderate IncontinencePatient with Moderate Incontinence
Patient with Severe IncontinencePatient with Severe Incontinence
Patient with Severe Incontinence
Tolterodine
Oxyibutynin [+]
Solifenacin [+]
Patient with OveractiveBladder in IMSS
• Developed with monthly cycles, adapted to model needs, and developed in Tree Age Pro 2008.
• Temporary analysis horizon of 12 months.
• A discount rate was not applied.
– costs – consequences
Study type andanalysis method
Effectiveness Measures
• The effectiveness measures used in the model are:
– Success:
• Patient without Incontinence
– Failure:
• Patient with Slight Incontinence.• Patient with Moderate Incontinence.• Patient with Severe Incontinence.
EffectivenessMeasures
Chart ***. Comparison of baseline characteristics of participants in the STAR and OBJECT studies,
receiving tolterodine, oxybutynin or solifenacin.
STAR Study OBJECT Study
Variable Oxybutynin Tolterodine Tolterodine Solifenacin
Sex: women 82.2% 84.5% 87.5% 87.1%
Age: average (d.e) 58.6 (13.4) 59.6 (13.2) 56.9 (NA) 56.5 (NA)
Race: Caucasian 87.6% 86.0% 99.3 99.3%
Urge – incontinence
(episodes/week)
25.5
(14.6)
24.6
(15.1)
1.66 x 7d*
=11.52
1.97 x 7d*
=13.79
Total incontinence
(episodes/week)
28.4
(17.8)
28.0
(18.3)
2.01 x 7d*
=14.07
2.32 x 7d*
=16.24
Urination frequency
(episodes/week)
92.9
(23.0)
91.8
(20.0)
11.36 x 7d*
=79.52
11.10 x 7d*
=77.70
NA: data not available
* Data from the OBJECT study were reported every 24 hours, therefore, these were adjusted forthe total week.
Chart ***. Comparative effectiveness (number of total urinary incontinence episodes)
of the three treatment regimes, according to the severity of the clinical
profile observed after 4 weeks of treatment
Treatment Sligh
t
Moderate
cases Severe
cases
Tolterodine 7.64 (21.505+7.64)=14.57 21.51
Oxybutynin 7.77 (21.159+7.77)=14.46 21.16
Solifenacin 7.14 (19.78+7.14)=13.46 19.78
EffectivenessMeasures
cases
Chart **. Transition probabilities of total urinary incontinence treatments after 4 weeks of
treatment, according to the severity of the clinical profile.
Severity after 4 weeks (%)
Severity Drug None Slight Moderate Severe
Severi
ty b
efo
re
treatm
en
t
Slight Tolterodine 44.19 42.56 13.04 0.21
Oxybutynin 44.23 42.27 13.30 0.21
Solifenacin 46.18 41.32 12.30 0.20
Moderate Tolterodine 23.79 46.83 28.33 1.05
Oxybutynin 24.38 46.30 28.22 1.09
Solifenacin 26.90 46.57 25.65 0.89
Severe Tolterodine 9.79 38.35 47.42 4.44
Oxybutynin 10.46 38.63 46.68 4.23
Solifenacin 12.63 41.16 42.95 3.27
Source: Adjusted results from the STAR and OBJECT Studies. (Appell & Chapple)
EffectivenessMeasures
Result of the review of the last bibliography sent by the Laboratory
1. ALEX C. WANG, 2006. Comparison of electric stimulation and oxybutynin chloride in management of overactive bladder with special reference to urinary urgency: a randomized placebo-controlled trial. Comment: Compared to placebo and electric stimulation, which are not management practices in Mexico.
2. Ananias Diokno, 2006. Oxybutynin in Detrusor Overactivity. Non-systematic review; not applicable to obtain effectiveness. Comment: Good review for marketing.
3. Regina D. Norris, 2008. A Prospective, Randomized, Double-Blinded Placebo-Controlled Comparison of Extended Release Oxybutynin Versus Phenazopyridine for the Management of Postoperative Ureteral Stent Discomfort. Comment: Clinical trial with a comparator not interesting for the Mexican Dromulary.
4. William D. Steers, 2006. Darifenacin: Pharmacology and Clinical Usage. Comment: Non-systematic review; not applicable to obtain effectiveness. Good review for marketing.
5. Ditropan XL Extended-Release Tablet (Tablet, Extended Release 5 mg). (Word document). Comment: Review document for laboratory use.
6. G. Willy Davila, 2006. Transdermal Oxybutynin for Overactive Bladder. Non-systematic review; not applicable to obtain effectiveness. Comment: Good review for marketing.
Results of the Cost-Effectiveness Analysis
Strategy CostIncremental
Cost Effectiveness
AverageCost-
EffectivenessRatio
Oxybutynin $5,576.77 7.113 $784.03
Solifenacin $7,719.11 $2,142.34 7.464 0.351 $1,034.21 $6,106.69
Tolterodine $11,975.99 $4,256.88 2.764 -4.700 $4,333.01 (Dominated)
IncrementalEffectiveness
IncrementalCost-
EffectivenessRatio
$0
$2,000
$4,000
$6,000
$8,000
$10,000
$12,000
$14,000
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00
Costo
Effectiveness
Cost-Effectiveness Analysis Patient with Overactive Bladder in IMSS
Oxybutynin Solifenacin Tolterodine Not Dominated
Results of the Cost-Effectiveness Analysis
Recommendations
• Tolterodine resulted dominated by the effectiveness (low) and price (high).
• The effectiveness of solifenacin vs. oxybutynin has a marginal gain, but there is considerable difference in price.
• Therefore, the recommendation is:
– Decrease the product price for the government to less than $87.5 pesos per box; with this, the monthly treatment cost of oxybutynin vs. solifenacin would allow to position it as a cost-effective alternative.