Cost–Utility Analysis of a Latanoprost Cationic Emulsion (STN1013001) versus Other Latanoprost in the Treatment of Open-Angle Glaucoma or Ocular Hypertension and Concomitant Ocular Surface Disease in Germany

Figures & data

Figure 1 Markov model.

Abbreviation: OAG/OHT, open-angle glaucoma or ocular hypertension.

Table 1 Unit Cost for Healthcare Resources, Utility and Disutility Values (Costs in €2020)

Model Main Items	Point Estimate (95% CI)^a,b		Source
OAG/OHT stages 0–5
OAG/OHT medications^c,^d
STN1013001	€0.30		Santen GmbH, 2020
Latanoprost	€0.29		32, 33
Add-on therapies^d,e
Acetazolamide	€0.28		32, 33
Brimonidine	€0.38		32, 33
Brinzolamide	€0.29		32, 33
Brinzolamide + brimonidine	€0.64		32, 33
Dorzolamide	€0.27		32, 33
Timolol	€0.06		32, 33
Timolol + dorzolamide	€0.42		32, 33
Healthcare procedures
Central corneal thickness	€4.33 (€3.48;€5.17)		34 [Code: 1204]
Diurnal curve of intraocular pressure measurement	€19.76 (€15.88;€23.63)		34 [Code: 1257]
Gonioscopy	€14.62 (€11.75;€17.49)		34 [Code: 1241]
Optic disk photographs	€14.42 (€11.59;€17.25)		34 [Code: 1253]
Pachimetry	€4.33 (€3.48;€5.17)		34 [Code: 1204]
Retinal nerve fibre thickness assessment	€69.83 (€56.14;€83.51)		34 [Codes: 1248;1249]
Slit lamp examination	€7.11 (€5.72;€8.50)		34 [Code: 1240]
Tonometry	€5.71 (€4.59;€ 6.83)		34 [Code: 1255]
Specialist visits
General practitioner	€8.57 (€6.89;€10.24)		Elaborated on 34 [Code: 1201]
Ophthalmologist	€8.57 (€6.89;€10.24)		34 [Code: 1201]
Optometrist	€8.57 (€6.89;€10.24)		Elaborated on 34 [Code: 1201]
Day-hospital access	€435.60 (€350.23;€520.98)		Elaborated on 35
Utility and disutility values^f	STN1013001^g	Latanoprost^h
OAG/OHT stage 0	0.900 (0.848;0.942)	0.900 (0.859;0.935)	30
OAG/OHT stage 1	0.900 (0.872;0.925)	0.899 (0.875;0.920)	Experts’ opinion
OAG/OHT stage 2	0.894 (0.866;0.919)	0.874 (0.846;0.900)	Experts’ opinion
OAG/OHT stage 3	0.873 (0.841;0.901)	0.847 (0.815;0.876)	Experts’ opinion
OAG/OHT stage 4	0.844 (0.816;0.869)	0.805 (0.775;0.832)	Experts’ opinion
OAG/OHT stage 5	0.790 (0.717;0.855)	0.790 (0.715;0.857)	30
OSD-related disutility	−0.120 (−0.231;-0.045)	−0.120(−0.231;-0.045)	31
Death	0.000 (-)	0.000 (-)	13, 14

Notes: ^a95% CI was calculated assuming a Normal probability distribution^15,39; ^b95% CI was not calculated for the unit cost of drugs since they are exogenous variables³⁹;^cMedications refer to STN1013001 and latanoprost only; ^dCost per diem calculated based on ex-factory price; ^eFollow-up drugs prescribed in addition to STN1013001 or latanoprost due to poor IOP control; ^f95% CI for utility and disutility values was calculated assuming a Beta and a Gamma probability distribution, respectively^15,39; ^gNumber of observations per OAG/OHT stage (female %): 0=155 (62.65%%); 1=500 (60.00%); 2=510 (61.18%); 3=470 (61.06%); 4=705 (53.62%); 5=131 (70.69%); ^hNumber of observations per OAG/OHT stage: 0=235 (64.47%); 1=662 (57.43%); 2=580 (61.12%); 3=530 (61.04%); 4=740 (53.92%); 5=125 (70.40%).

Abbreviations: CI, confidence interval; IOP, intraocular pressure; OAG/OHT, open-angle glaucoma/ocular hypertension; OSD, ocular surface disease.

Figure 2 (A) Markov trace for the hypothetical cohort of patients on STN1013001. (B) Markov trace for the hypothetical cohort of patients on latanoprost.

Abbreviation: OAG/OHT, open-angle glaucoma or ocular hypertension.

Table 2 Costs per Patient and Cost–Utility Analysis (Costs in €2020)

Items	STN1013001 (%)	Latanoprost (%)		Difference (%) [95% CI]^a,b
German health system viewpoint
Cost
Diagnosis	€75.41 (7.51)	€68.90 (6.02)		€6.50 (−4.59) [−€2.05;€15.43]
Medications	€356.18 (35.49)	€319.18 (27.87)		€37.00 (−26.11) [€26.94;€51.77]
Add-on therapies and follow-up	€488.85 (48.71)	€648.82 (56.65)		−€159.96 (112.86) [−€217.88;-€114.23]
OSD management	€83.21 (8.29)	€108.48 (9.47)		−€25.26 (17.84) [−€39.90;−€13.41]
Overall	€1003.65 (100.00)	€1145.37 (100.00)		−€141.73 (100) [−€202.51;-€88.33]
LYS and QALYs
LYS	3.998	4.035		−0.037 [−0.091;0.028]
QALYs	2.612	2.365		0.247 [0.122;0.407]
Cost–utility analysis - Basecase
Incremental costs (ΔC)	-€141.73
Incremental QALYs (ΔQALYs)	0.247
ICUR (ΔC/ΔQALYs)	STN1013001 is strongly dominant (SE sector of the cost-effectiveness plane)

Notes: ^a(STN1013001 – Latanoprost); ^b95% CI was calculated via the percentile method³⁹.

Abbreviations: CI, confidence interval; ICUR, Incremental Cost–Utility Ratio; LYS, Life-Years Saved; OAG/OHT, open-angle glaucoma/ocular hypertension; OSD, ocular surface disease; QALYs, Quality-Adjusted Life Years; SE, South-East.

Figure 3 One-way sensitivity analysis: results concerning the first 10 parameters of the Markov model that causes the widest variations in base case ICUR (€2020).^a,b

Notes: ^aBase case ICUR STN1013001: strongly dominant (SE sector of the cost-effectiveness plane); ^bY and X-axes intersect at the baseline ICUR.

Abbreviations: ICUR, Incremental Cost–Utility Ratio; LL 95% CI, lower limit 95% confidence interval; OAG/OHT, open-angle glaucoma or ocular hypertension; SE, South-East; UL 95% CI, uUpper limit 95% confidence interval.

Figure 4 Probabilistic sensitivity analysis. Cost-effectiveness plane (10,000 out of 10,000 Monte Carlo iterations reported) (ΔC in €2020).^a,b

Notes: ^aBase case ICUR STN1013001: strongly dominant (SE sector of the cost-effectiveness plane); ^bNumber of Monte Carlo iterations (%) for each sector of the cost-effectiveness plane: SE=10,000 (100.00%).

Abbreviations: ΔC, incremental cost; ΔQALYs, incremental quality-adjusted life years; ICUR, Incremental Cost–Utility Ratio; SE, South-East.

Figure 5 Probabilistic sensitivity analysis. Cost-effectiveness acceptability curve (1000 out of 1000 threshold values reported) (€2020).^a

Notes: ^aBase case ICUR STN1013001: strongly dominant (SE sector of the cost-effectiveness plane).

Abbreviations: CEAC, cost-effectiveness acceptability curve; ICUR, Incremental Cost–Utility Ratio; SE, South-East.

Figure 6 Probabilistic sensitivity analysis. Cost-effectiveness acceptability frontier (1000 out of 1000 threshold values reported) (€2020).^a,b

Notes: ^aBase case ICUR STN1013001: strongly dominant (SE sector of the cost-effectiveness plane); ^bCEAF: STN1013001 is the optimal strategy from a threshold value of €0.00 onwards.

Abbreviations: CEAF, cost-effectiveness acceptability frontier; ICUR, Incremental Cost–Utility Ratio; SE, South-East.

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