Changes of the Types and Daily Costs of Topical Antiglaucoma Medications from 2006 to 2021 in China
Abstract
Purpose. To investigate the changes of the types and daily costs of topical antiglaucoma medications from 2006 to 2021 in China, providing evidence for optimizing treatment regimen and medical insurance policy. Methods. The types of topical antiglaucoma drugs except complementary and traditional medicines and associated price information were collected from the largest pharmaceutical database in China (YAOZH database). The daily costs of each drug, the average income level, and the daily cost of topical antiglaucoma medications relative with daily disposable income were calculated and compared between 2006 and 2021. Results. The options of topical antiglaucoma drugs increased remarkably to 32 types in 2021, of which prostaglandin analogs comprised the largest proportion (31.25%). There were 10 types of the same brand drugs available in 2006 and 2021, the mean daily cost of which decreased from $0.39 ± 0.30 to $0.28 ± 0.23 (p < 0.001). As the average daily disposable income of Chinese residents grew greatly, the proportion of the daily cost of topical antiglaucoma medications in daily disposable income in 2021 declined significantly from 32.52% to 5.78% (all the drugs, p < 0.001) and 3.94% (without unit dose package, p < 0.001) in rural areas and from 9.95% to 2.31% (all the drugs, p < 0.001) and 1.57% (without unit dose package, p < 0.001) in urban areas. Conclusions. Topical antiglaucoma medications available become much more abundant in China. With the increase of residents’ disposable income and reduction of daily costs of topical antiglaucoma medications, the drug treatment for glaucoma becomes more affordable both in rural and urban areas.
1. Introduction
Glaucoma, which is the leading cause of global irreversible blindness, has been estimated to affect approximately 111.8 million people worldwide in 2040 [1, 2]. In Asia, there are almost 60% of all the glaucoma patients around the world and the prevalence is as high as 3.54% [3]. China is the most populated country in Asia and will face persistent financial burden on the treatment of growing glaucoma patients, which was estimated to reach 25.16 million by 2050 [4]. Therefore, how to make the treatment of glaucoma affordable is a crucial problem for both health economists and health care providers. It is well accepted that lowering intraocular pressure (IOP) is the only approach proven to be effective in slowing the progression of glaucoma [5]. Despite the occurrence of various types of treatment methods, topical pressure-lowering medication is still the priority in most cases currently [6]. Since the medication is always used in the long-term, the cost of medication is probably the most important factor to determine the total cost of treatment according to Chan et al.’s study [7]. In the last decades, novel antiglaucoma medications with a wide range of prices including fixed-dose combinations and unit dose package have been commercially available. Although the drug effectiveness is crucial to control the disease progression, the medication costs also have an impact on the patient’s adherence to topical glaucoma therapy to some extent [8], thus influencing the doctor’s choice. In 2006, we once calculated the daily costs of all the antiglaucoma drugs available in China [9]. Prostaglandin analogs (PGAs) are the first-line medical therapy for open angle glaucoma [5, 10], the options of which were much limited and the relatively high daily costs comparing to the Chinese resident’s income level restricted their use in 2006 [9]. However, during the last 15 years, topical antiglaucoma medications have become much more abundant in China including the PGAs. Besides, the daily costs of different drugs and the resident’s income level also changed a great deal. Likewise, the economic burden of the topical glaucoma treatment on patients altered greatly, which was unknown and required further investigation. In this study, we took the same approach as our previous publication [9] to determine the daily costs of topical antiglaucoma medications in 2021 and further investigated the proportion of the daily costs of topical antiglaucoma medications in the average daily disposable income of Chinese residents. Comparisons of the above information were made between 2006 and 2021 with less consideration of the efficacy differences of various drugs. This study comprehensively summarized the changes of the types, daily costs, and financial burden relative with the income level of topical antiglaucoma medications from 2006 to 2021, which was aimed to optimize drug selection for both doctors and patients.
2. Methods
2.1. Collection of Drug Data
All the information about the topical antiglaucoma medications available in China were collected from the YAOZH database. YAOZH database is the largest pharmaceutical database in China, containing the bid information of various drugs in different provinces of mainland China. Briefly, we visited the official website of YAOZH database (https://www.yaozh.com) and selected “Bid information of drugs” in the drop down of the “Market information” on the top menu. Then, we could have access to the searching service, through which we retrieved the product names, manufacturers, compositions, volumes, specifications, and market prices of all the topical antiglaucoma medications available by the end of December 31, 2021, by entering the pharmaceutical ingredients of the six categories of antiglaucoma eye drops, respectively (prostaglandin analogs, β-adrenergic blocker, carbonic anhydrase inhibitor, α2-adrenergic agonist, cholinergic, and fixed-dose combinations). The topical antiglaucoma medications covered various dosage forms of antiglaucoma eye drops without complementary and traditional medicines.
2.2. Retrieval of Income Level Data and the Exchange Rate
The data of National Per Capita Disposable Income of China was originated from the Statistical Bulletin of the People’s Republic of China on National Economic and Social Development in 2006 (Attachment from https://www.stats.gov.cn/xxgk/sjfb/tjgb2020/201310/t20131031_1768613.html) and 2021 (online data from https://www.stats.gov.cn/english/PressRelease/202202/t20220227_1827963.html). Considering the stability of the purchasing power of US dollars, we converted the market prices from China Yuan (CNY) to US dollar for better comparison with other studies. The CNY exchange rate against US dollar was 1 US dollar = 8.2889 CNY (our study [9] in 2006) and 1 US dollar = 6.3757 CNY (by the end of December 31, 2021) according to the searching results of the exchange rate from the website (https://www.boc.cn/sourcedb/whpj/enindex2.htm).
2.3. Data Analysis
The method by which we determined the number of drops per bottle, the volume per bottle, the volume per drop, the cost per drop, the number of days for both eyes per bottle, and the cost per day was the same as our previous study [9]. The cost per day was calculated by multiplying the cost per drop by the number of drops administered daily for both eyes. We compared the market prices and daily costs of the same brand topical antiglaucoma drugs between 2006 and 2021. Considering the limited choices of drugs in 2006, we finally included 10 types of drugs into comparison. Besides, the mean daily cost of all the topical antiglaucoma drugs and the proportion of daily cost of topical antiglaucoma medications in the National Per Capita Daily Disposable Income of China were compared between 2006 and 2021. Since the drugs of unit dose package are much more expensive than other ordinary dosage forms, we calculated the daily costs including or excluding unit dose package separately to avoid biases. The daily costs and the proportions were further presented as mean value ± standard deviation (SD). In this study, all the statistical analyses were performed using Statistical Package for the Social Sciences software, version 26.0 (SPSS Inc., Chicago, IL). T test was used to compare the mean value, and P values of <0.05 were considered to indicate statistically significant differences.
3. Results
Table 1 showed the specific price information and daily costs of all the topical antiglaucoma medications currently in clinical use in China in 2021. There were 32 options of topical antiglaucoma drugs in 2021, including multiple fixed-dosed combinations and unit dose package with no preservatives. Besides, PGAs comprised the largest proportion (31.25%) of all the topical antiglaucoma medications available, followed by β-adrenergic blockers (28.13%). The daily costs of topical antiglaucoma drugs for both eyes ranged from $0.05 (timolol maleate 0.5%, Chengrui, Shandong Bausch & Lomb Furuida, China) to $2.51 (carteolol hydrochloride 2%, Mikelan, unit dose package, Otsuka, China-Japan). Since the drugs with unit dose package applied to specific patients with vulnerable cornea, the prices were relatively higher than the average market price of ordinary dosage forms. If the drugs with unit dose package were excluded, the highest daily cost for both eyes was $0.74 (travoprost 0.004%, Travatan, Alcon, United States).
| Classifications | Trade name | Active ingredient (concentration) | Manufacturer | No. drops/bottle | Volume/bottle (mL) | Volume/drop (μL) | No. drops for both eyes per day | PriceaUS dollarsb | Cost/drop US dollars | No. days/bottle (both eyes) | Cost/day (both eyes) US dollars |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Prostaglandin analogs | Xalatan | Latanoprost 0.005% | Pfizer, United States | 88.3 ± 0.47 | 2.5 | 28.3 ± 0 | 2 | 26.76 | 0.30 | 44 | 0.61 |
| Ruidaxi | Latanoprost 0.005% | Taejun, Korea | 79.7 ± 0.47 | 2.5 | 31.4 ± 0.5 | 2 | 15.51 | 0.19 | 39 | 0.39 | |
| Telijie | Latanoprost 0.005% | Lunan Beite, China | 76.7 ± 0.58 | 2.5 | 32.6 ± 0.5 | 2 | 18.95 | 0.25 | 38 | 0.49 | |
| Jiankang | Latanoprost 0.005% | Huarun Zizhu, China | 78.3 ± 1.15 | 2.5 | 32.0 ± 0 | 2 | 20.91 | 0.27 | 39 | 0.53 | |
| Shengao | Latanoprost 0.005% | Chengdu Hengrui, China | 76.3 ± 2.31 | 2.5 | 32.8 ± 0.5 | 2 | 16.24 | 0.21 | 38 | 0.43 | |
| Travatan | Travoprost 0.004% | Alcon, United States | 71.3 ± 1.25 | 2.5 | 35.0 ± 0.8 | 2 | 26.40 | 0.37 | 35 | 0.74 | |
| Nuoming | Travoprost 0.004% | Hubei Yuanda, China | 76.3 ± 4.04 | 2.5 | 32.8 ± 1.7 | 2 | 23.96 | 0.31 | 38 | 0.63 | |
| Lumigan | Bimatoprost 0.03% | Allergan, United States | 110.7 ± 0.47 | 3 | 27.1 ± 0 | 2 | 21.96 | 0.20 | 55 | 0.40 | |
| Tafluprost | Tafluprost 0.0015% | Santen, Japan | 89.0 ± 2.16 | 2.5 | 28.1 ± 0.8 | 2 | 11.73 | 0.13 | 44 | 0.26 | |
| Tafluprost | Tafluprost 0.0015% (unit dose package: 0.3 ml × 30/box) | Santen, Japan | 60.0 ± 0.00 (2 × 30)c | 9.0 (0.3 ml × 30) | 150 ± 0 | 2 | 69.45 | 1.16 | 30 | 2.32 | |
| β-adrenergic blocker | Wujing | Timolol maleate 0.5% | Wuhan Wujing, China | 116.33 ± 2.05 | 5 | 43.0 ± 0.8 | 4 | 3.39 | 0.03 | 29 | 0.12 |
| Tiantianming | Timolol maleate 0.25% (unit dose package: 0.4 ml × 15/box) | Hubei Yuanda, China | 30 ± 0.00 (2 × 15)c | 6 (0.4 ml × 15) | 200 ± 0 | 4 | 7.06 | 0.24 | 7 | 0.94 | |
| Xiutong | Timolol maleate 0.5% | Guangdong Hongying, China | 153.0 ± 15.56 | 5 | 32.7 ± 2.8 | 4 | 3.11 | 0.02 | 38 | 0.08 | |
| Chengrui | Timolol maleate 0.5% | Shandong Bausch & Lomb Furuida, China | 118.0 ± 0.82 | 5 | 42.4 ± 0.5 | 4 | 1.51 | 0.01 | 29 | 0.05 | |
| Yuanheng | Timolol maleate 0.25% | Jiangsu Yuanheng, China | 104.3 ± 2.08 | 5 | 48.0 ± 1.0 | 4 | 3.05 | 0.02 | 26 | 0.06 | |
| Betoptic | Betaxolol hydrochloride 0.25% | Alcon, United States | 227 ± 6.98 | 5 | 22.0 ± 0.8 | 4 | 5.60 | 0.03 | 56 | 0.10 | |
| Mikelan | Carteolol hydrochloride 1% | Otsuka, China-Japan | 124.33 ± 3.68 | 5 | 40.2 ± 1.2 | 4 | 2.80 | 0.02 | 31 | 0.09 | |
| Mikelan | Carteolol hydrochloride 2% | Otsuka, China-Japan | 122 ± 1.41 | 5 | 41.0 ± 0.5 | 4 | 3.46 | 0.03 | 30 | 0.11 | |
| Mikelan | Carteolol hydrochloride 2% (unit dose package: 0.6 ml × 10/box) | Otsuka, China-Japan | 20 ± 0.00 (2 × 10)c | 6 (0.6 ml × 10) | 300 ± 0 | 4 | 12.55 | 0.63 | 5 | 2.51 | |
| Carbonic anhydrase inhibitor | Azopt | Brinzolamide 1% | Alcon, United States | 150.7 ± 0.47 | 5 | 33.2 ± 0 | 4 | 9.66 | 0.06 | 37 | 0.26 |
| α2-Adrenergic agonist | Alphagan | Brimonidine tartrate 0.2% | Allergan, United States | 152 ± 3.56 | 5 | 32.9 ± 0.9 | 4 | 10.65 | 0.07 | 38 | 0.28 |
| Alphagan | Brimonidine tartrate 0.15% | Allergan, United States | 114.7 ± 1.88 | 5 | 43.6 ± 0.9 | 4 | 11.23 | 0.10 | 28 | 0.39 | |
| Zhuoneng | Brimonidine tartrate 0.2% | Nanjing Hengsheng, China | 136.0 ± 2.65 | 5 | 36.8 ± 0.5 | 4 | 6.56 | 0.05 | 34 | 0.19 | |
| Huonland | Brimonidine tartrate 0.2% | Beijing Huonland, China | 158 ± 4.55 | 5 | 31.6 ± 1.2 | 4 | 6.56 | 0.04 | 39 | 0.16 | |
| Cholinergic | Zhenrui | Pilocarpine nitrate 2% | Shandong Bausch & Lomb Furuida, China | 112.3 ± 0.94 | 5 | 44.5 ± 0.3 | 8 | 2.27 | 0.02 | 14 | 0.16 |
| Zezhu | Pilocarpine nitrate 0.5% | Anhui Shuangke, China | 103 ± 1.41 | 5 | 48.5 ± 0.5 | 8 | 5.73 | 0.05 | 12 | 0.44 | |
| Yongguang | Pilocarpine nitrate 1% | Yongguang, China | 154.3 ± 0.47 | 5 | 32.4 ± 0 | 8 | 1.13 | 0.01 | 19 | 0.06 | |
| Fixed-dose combinations | Xalacom | Latanoprost 0.0025% and timolol maleate 0.272% | Pfizer, United States | 88.7 ± 0.94 | 2.5 | 28.2 ± 0 | 2 | 29.73 | 0.34 | 44 | 0.67 |
| Duotrav | Travoprost 0.004% and timolol maleate 0.5% | Alcon, United states | 84.7 ± 2.05 | 2.5 | 29.5 ± 0.5 | 2 | 28.93 | 0.34 | 42 | 0.68 | |
| Ganfort | Bimatopros 0.03% and 0.5% timolol | Allergan, Ireland | 105.3 ± 2.36 | 3 | 28.5 ± 0.5 | 2 | 23.41 | 0.22 | 52 | 0.45 | |
| Azarga | Brinzolamide 1% and timolol 0.5% | Alcon, United states | 149.3 ± 3.86 | 5 | 33.5 ± 0.9 | 4 | 6.43 | 0.04 | 37 | 0.17 | |
| Simbrinza | Brinzolamide 1% and brimonidine tartrate 0.2% | Novartis, Switzerland | 133 ± 1.63 | 5 | 37.6 ± 0.5 | 4 | 9.88 | 0.07 | 33 | 0.29 | |
- aThe prices of different antiglaucoma drugs were originated from YAOZH database (https://www.yaozh.com) by the end of December 31, 2021. b1 US dollar = 6.3757CNY (by the end of December 31, 2021). cAccording to the instructions of the drugs with unit dose package, every single package can be used for two droplets. The volume/drop is calculated accordingly.
In Table 2 and Figure 1, we compared the daily costs of the same brand topical antiglaucoma drugs between 2006 and 2021, based on our previous study [9]. There were 10 types of drugs both available in 2006 and 2021. The mean market price of the drugs was $11.17 ± 10.10 in 2021, which declined significantly compared with $18.36 ± 18.86 in 2006 (p < 0.001). Likewise, the daily cost of these drugs in 2021 ($0.28 ± 0.23) was significantly lower than that in 2006 ($0.39 ± 0.30, p < 0.001). Except timolol maleate 0.5% (Wuhan Wujing, China), the daily cost of the other drugs, mostly imported drugs, decreased by 4–58% (Figure 1).
| Trade name | Active ingredient (concentration) | Manufacturer (2021) | Pricea(2006) US dollarsb | Price (2021) US dollarsc | Cost/daya(2006) US dollarsb | Cost/day (2021) US dollarsc | Change of cost/day (2021–2006) | Change rate of cost/day (2021–2006) |
|---|---|---|---|---|---|---|---|---|
| Alphagan | Brimonidine tartrate 0.2% | Allergan, United States | 15.09 | 10.65 | 0.61 | 0.28 | −0.33 | −54% |
| Mikelan | Carteolol hydrochloride 2% | Otsuka, China-Japan | 5.65 | 3.46 | 0.15 | 0.11 | −0.04 | −27% |
| Wujing | Timolol maleate 0.5% | Wuhan Wujing, China | 0.89 | 3.39 | 0.03 | 0.12 | +0.09 | +300% |
| Chengrui | Timolol maleate 0.5% | Shandong Bausch & Lomb Furuida, China | 2.17 | 1.51 | 0.08 | 0.05 | −0.03 | −38% |
| Betoptic | Betaxolol hydrochloride 0.25% | Alcon, United States | 9.08 | 5.60 | 0.24 | 0.10 | −0.14 | −58% |
| Zhenrui | Pilocarpine nitrate 2% | Shandong Bausch & Lomb Furuida, China | 4.24 | 2.27 | 0.28 | 0.16 | −0.12 | −43% |
| Azopt | Brinzolamide 1% | Alcon, United States | 15.61 | 9.66 | 0.34 | 0.26 | −0.08 | −24% |
| Travatan | Travoprost 0.004% | Alcon, United States | 46.75 | 26.41 | 0.77 | 0.74 | −0.03 | −4% |
| Lumigan | Bimatoprost 0.03% | Allergan, United States | 31.06 | 21.97 | 0.46 | 0.40 | −0.06 | −13% |
| Xalatan | Latanoprost 0.005% | Pfizer, United States | 53.03 | 26.76 | 0.91 | 0.61 | −0.3 | −33% |
| Mean ± SD | 18.36 ± 18.86 | 11.17 ± 10.10 | 0.39 ± 0.30 | 0.28 ± 0.23 | ||||
| Pd | <0.001 | <0.001 | ||||||
- aThe prices of different antiglaucoma drugs and daily costs in 2006 were originated from the previous study (Gao Y, Wu L, Li A. Daily cost of glaucoma medications in China. J Glaucoma. 2007; 16(7):594–597.). b1 US dollar = 8.2889 CNY (2006). c1 US dollar = 6.3757 CNY (2021). dP value was analyzed by pair t test.
According to Table 3, both the annual and daily disposable income of Chinese citizens increased to a large degree in the last 15 years. In 2021, the National Per Capita Daily Disposable Incomes of rural residents and urban residents were $8.14 and $20.38, respectively, 5.86 and 4.24 times higher than those of 2006.
| Annual disposable incomea | Daily disposable incomea | |||||
|---|---|---|---|---|---|---|
| 2006 US dollarsb | 2021 US dollarsc | Growth (fold) | 2006 US dollarsb | 2021 US dollarsc | Growth (fold) | |
| Rural residents | 433 | 2969 | 5.86 | 1.19 | 8.14 | 5.86 |
| Urban residents | 1419 | 7436 | 4.24 | 3.89 | 20.37 | 4.24 |
- aThe data were according to the statistical bulletin of the People’s Republic of China on National Economic and Social Development in 2006 and 2021. b1 US dollar = 8.2889 CNY (2006). c1 US dollar = 6.3757 CNY (2021).
Table 4 revealed the change of the proportion of the daily costs of topical antiglaucoma medications in average daily disposable income between 2006 and 2021. We calculated the daily costs of the topical antiglaucoma drugs in 2021 with or without unit dose package, respectively. Taking the unit dose package into consideration, the mean daily cost increased a little in 2021 ($0.47 ± 0.56). On the contrary, the mean daily cost without unit dose package ($0.32 ± 0.21) was lower than that in 2006. However, no matter with or without unit dose package, there was no significant difference in the daily cost compared with that ($0.39 ± 0.30) in 2006 (p, 0.499 and 0.207). In terms of the daily cost of topical antiglaucoma medications relative with the average daily disposable income, it decreased significantly from 32.52% (2006) to 5.78% (2021, all the drugs, p < 0.001) and 3.94% (2021, without unit dose package, p < 0.001) in rural residents; in urban areas, the proportion declined from 9.95% (2006) to 2.31% (2021, all the drugs, p < 0.001) and 1.57% (2021, without unit dose package, p < 0.001). As for the most expensive drug, the proportion of daily cost in average daily disposable income in 2021 was 30.84% in rural areas and 12.32% in urban areas, significantly lower than 76.47% and 23.39% in 2006.
| Year | Cost/day (US dollars) | Proportion (rural)a (%) | Proportion (urban)b (%) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max | Min | Mean ± SD | Pd | Max | Min | Mean ± SD | Pd | Max | Min | Mean ± SD | Pd | |
| 2006 | 0.91 | 0.03 | 0.39 ± 0.30 | — | 76.47 | 2.52 | 32.52 ± 24.87 | — | 23.39 | 0.77 | 9.95 ± 7.61 | — |
| 2021c | 2.51 | 0.05 | 0.47 ± 0.56 | 0.499 | 30.84 | 0.61 | 5.78 ± 6.89 | <0.001 | 12.32 | 0.25 | 2.31 ± 2.75 | <0.001 |
| 2021 (unit dose package excluded) | 1.06 | 0.05 | 0.32 ± 0.21 | 0.207 | 13.02 | 0.61 | 3.94 ± 2.64 | <0.001 | 5.2 | 0.25 | 1.57 ± 1.05 | <0.001 |
- aThe proportion of daily cost of antiglaucoma medications in daily disposable income of rural residents. bThe proportion of daily cost of antiglaucoma medications in daily disposable income of urban residents. cAll the antiglaucoma drugs were included in calculation besides the same brand drugs already in use in 2006. dP values were analyzed by t-test, respectively, for all the antiglaucoma drugs in 2021 and antiglaucoma drugs without unit dose package in 2021, compared with those in 2006. 1 US dollar = 8.2889 CNY (2006). 1 US dollar = 6.3757 CNY (2021).
4. Discussion
In this study, we found that topical antiglaucoma medications commercially available in China became abundant with the options of 32 types in total in 2021. PGAs increased from 3 types (2006) to 10 types (2021), accounting for the largest proportion (31.25%) of all the topical antiglaucoma medications. Among the monotherapy medications, PGAs could achieve the highest reduction of IOP with the less daily usage frequency and systemic side effects and were considered as the initial treatment though expensive in some countries [11–13]. Following the PGAs, β-adrenergic blockers comprised 28.12% of the glaucoma medications, which once had the most choices (44%) in 2006 [9]. Besides the increase of the medication types, the advent of various dosing patterns including 5-type fixed combinations and 3-type unit dose packages could serve patients with different ocular complications better. Fixed combinations have the advantage of no flushing effects between different drugs, less total usage frequency, and less damage to the ocular surface, thus improving the patient’s compliance in a sense. The preservatives in topical glaucoma medications are confirmed to exert deleterious effects on the ocular surface with resultant tear film instability and dry eye disease [14]. Therefore, medications with unit dose package provide preservative-free choices for patients with ocular surface diseases who are less tolerate for ordinary glaucoma drugs.
The daily costs of different topical antiglaucoma drugs vary a lot from each other in China. The most affordable drug in 2021 was the timolol maleate 0.5% (Chengrui, Shandong Bausch and Lomb Furuida, China) with the daily cost of $0.05, which was similar to that in 2006. Previous studies [9, 15–18] also supported the same conclusion that nonselective β-blockers remained the most inexpensive class of antiglaucoma medications in most developed and developing countries. In fact, the daily cost of topical β-blockers in China was the lowest and most affordable across the five continents [16]. Considering the daily costs calculated for both eyes and the change of the CNY-US dollar exchange rate, the lowest daily cost of timolol maleate 0.5% ($0.05) in our study was higher than $0.02 estimated in Zhao et al.’s study [16]. The most expensive drug was carteolol hydrochloride 2% with unit dose package (Mikelan, unit dose package, Otsuka, China-Japan) with the daily cost of $2.51. In fact, only the daily costs of the three types of drugs with unit dose package (Table 1) surpassed 1 US dollar, which restricted its use despite the less irritation to the ocular surface. In terms of all the types of fixed combinations, Azarga (Alcon, United states) was the cheapest with $0.17 per day in China; Xu et al. discovered that Azarga had the lowest daily cost and best cost effectiveness when comparing all the fixed combination glaucoma drugs in China [19], the result of which was similar to our study. Comparing the daily costs of the fixed combinations of β-blocker and carbonic anhydrase inhibitor worldwide, we found United Kingdom had lower daily cost ($0.12) than China; except the UK, the daily costs in all the other counties (ranging from $0.31 to $ 2.10) were more expensive than China [16]. As for the daily costs of the fixed combinations of PGA and β-blocker, Ganfort (Allergan, Ireland) was the most affordable choice with $0.45 per day. Likewise, in Europe, the fixed combination of bimatoprost 0.03% and timolol 0.5% (Ganfort) showed the lowest medication prices per month for primary open-angle glaucoma [20].
According to Figure 1, the market price and daily costs of the same brand antiglaucoma drugs decreased significantly except timolol maleate 0.5% (Wuhan Wujing, China) during the last 15 years. In 2006, there were only three types of PGAs available and all of them were obviously more expensive than other drugs. However, in 2021, the daily costs of PGAs declined remarkably; among them, the market price of Xalatan decreased the most from $53.03 to $26.77 and the daily cost decreased by 33% to $0.61. Besides, the lowest daily cost of PGAs in 2021 was only $0.26 (tafluprost 0.0015%, Santen, Japan) in China. In Americas and Europe, Canada and Britain had lower daily cost of PGAs than China with $0.24 and $0.08, respectively [16]. In Africa, PGAs costed the least in Egypt with $1.03 per day. As for the daily costs of PGAs in Asia, Israel, and Japan shared the lowest cost of $0.36 per day [16], which was also more expensive than that in China. Due to the reduction of daily costs, PGAs became much more affordable and acceptable for many patients nowadays in China.
In order to comprehensively understand the economic burden of topical antiglaucoma medications on Chinese residents, we took the change of daily disposable income of the Chinese citizens into consideration as well. The average daily disposable income of Chinese citizens in 2021 increased by 6.86 times and 5.24 times in rural and urban areas, respectively, against 2006 (Table 3), owing to the rapid development of the economy. Combined with the fact that the daily costs of many antiglaucoma drugs decreased in 2021, the proportions of the daily costs of antiglaucoma medications in daily disposable income declined significantly both in rural and urban areas (Table 4). According to the criterion in Zhao et al.’s study [16], interventions costing less than 2.5% of the median annual household income were considered affordable. Similarly, we assumed that the daily cost of medications less than 2.5% of the average daily disposable income was considered as affordable. In urban areas, the mean daily costs of antiglaucoma medications with or without unit dose package were 2.31% and 1.57% of the daily disposable income, both lower than 2.5%. However, in rural areas, the mean daily costs of antiglaucoma medications were still more than 2.5% of the average daily income (5.78% all and 3.94% without unit dose package). Despite the relative high proportion noted in rural area, the minimal daily cost of antiglaucoma medications (0.61%) was much lower than 2.5% of the average daily income. Therefore, the financial burden of antiglaucoma medications reduced to a large extent both in urban and rural areas in China. Most drugs were affordable in urban areas with the increased daily disposable income. By contrast, some drugs might still be expensive for people in rural area with less daily income.
This study showed that the daily cost of antiglaucoma medications in 2021 (without unit dose package) decreased to some extent compared with that in 2006 while there was no significant difference. In fact, if we compared the numerical numbers of the daily costs in CNY between 2006 and 2021, it would show significant differences. It was the change of the CNY exchange rate against US dollar that accounted for this difference. Despite the reduction of market prices of many drugs, the CNY exchange rate against US dollar increased from 8.2889 to 6.3757, which made the reduction of prices less prominent when converted to US dollars.
One strength of this study is the coverage of all the topical antiglaucoma medications currently available in China, including multiple dosage forms. The other strength is that we also noted the change of Chinese residents’ income level during the last 15 years, which had an influence on the patient’s economic burden of topical glaucoma treatment in addition to the daily costs of the drugs.
However, there are still some limitations in this study. First, this study did not perform the subanalysis on the different districts and provinces in China. The income level varies from each other in different regions of China, which means the financial burden of topical antiglaucoma medications might be different. Besides, the cost-effectiveness of different glaucoma drugs and the correlations between the drug prices and the patient’s behavior were not investigated.
5. Conclusion
Our study compared the types and daily costs of topical antiglaucoma medications thoroughly between 2006 and 2021. During the last 15 years, the choices of topical antiglaucoma medications have become much more abundant in China, including various dosage forms and packing sizes. PGAs, as the first-line treatment for primary open-angle glaucoma, used to be expensive for most patients with limited choices in 2006. However, the options of PGAs have been largely enriched in 2021 and the daily costs become more affordable to the general public. In terms of the changes of the daily costs between 2006 and 2021, the mean daily costs of the same brand topical antiglaucoma drugs (both available in 2006 and 2021) decreased significantly. In addition, since the daily income level of Chinese residents had experienced a great growth from 2006 and 2021, the daily cost of topical antiglaucoma medications relative with the daily disposable income decreased significantly both in rural and urban areas. In summary, with plenty of choices and reduced daily costs, the majority of the topical antiglaucoma medications have become more affordable both in rural and urban areas of China. Further research studies are needed to investigate the cost-effectiveness of different antiglaucoma medications with the updated daily costs and the correlation between the drug prices and the patient’s behavior.
Ethical Approval
No patients or animals were involved in this study.
Conflicts of Interest
The authors declare no conflicts of interest.
Acknowledgments
This study was supported by the Peking University Third Hospital Cohort Study Funding Project (Grant number: BYSYDL2021015).
Open Research
Data Availability
All the original data that support the findings of this study are available on request from the corresponding author.
