Drug Utilization and Medical Cost Study Focusing on Moisturizers in Cancer Patients Treated with Molecular Targeted Therapy: A Retrospective Observational Study Using Data from a Japanese Claims Database
Molecular targeted therapies (MTTs) cause skin disorders in patients with cancer, and moisturizers are useful treatments; however, their actual use and costs are unknown. Our purpose was to examine the use and costs of moisturizers prescribed for xerosis (asteatosis) in patients with cancer treated with MTTs.
Methods
We used data from a Japanese hospital-based claims database. The index date was the first date of MTT prescription from October 2011 to April 2018 (selection period), and the follow-up period was 1 year from the index date. Patients treated with MTTs during the selection period and who were not prescribed moisturizers in the 6 months before the index date were included as the study cohort. Timing, duration, amount, and costs of the prescribed moisturizers and total medical costs were analyzed.
Results
Among the 78,190 patients in the study cohort, 27,906 patients (35.7%) were prescribed moisturizers during follow-up. Moisturizer prescription timing, duration, and volume were inconsistent. The average annual total medical costs for treating patients with MTT who were prescribed moisturizers was JPY 6.165 million (USD 53,797) per patient, and the moisturizer costs were JPY 6033 (USD 53). The number of patients who used moisturizers showed an increasing trend.
Conclusion
No consistent patterns were observed for the timing or duration of moisturizer use, which suggests various developmental patterns of skin disorders. Furthermore, medical costs for moisturizers accounted for only a small proportion of the total medical costs required for cancer treatment.
Moisturizers are used for skin disorders caused as an adverse reaction of molecular targeted therapies in patients with cancer.
Cost and use of moisturizers are not clear in clinical practice.
This study was to analyze the use and costs of moisturizers in patients treated with molecular targeted therapies, using a health insurance claims database.
What was learned from the study?
Moisturizer prescription timing, duration, and volume were inconsistent.
The moisturizer costs were only a small proportion of the total medical costs required for cancer treatment, and use of moisturizers may contribute to continuation of molecular targeted therapy (MTT) treatment.
Introduction
Among anticancer drugs, molecular targeted therapies (MTTs), particularly epidermal growth factor receptor (EGFR) inhibitors, multikinase inhibitors, and BCR-ABL tyrosine kinase inhibitors, may cause skin disorders as an adverse reaction. Patients may develop hand–foot syndrome (HFS), xerosis (asteatosis), and acneiform folliculitis, and moisturizers are used as treatments [1]. Clinical practice guidance in Japan [2] evaluates the topical application of moisturizers for HFS, xerosis, and acneiform folliculitis caused by treatment with MTTs. Topical application of moisturizers is a grade B recommendation (recommendable with evidence) for HFS and is considered “useful and recommended.” The recommendation grade for xerosis is C1a (can be used, but, because of insufficient scientific evidence, is less recommendable than therapies with evidence), and “the use of moisturizers taking advantage of their characteristics is recommended in order to improve dermatitis and subjective symptoms.” The recommendation grade for acneiform folliculitis is C1b (no evidence, but the use is not denied), and the guidance states that “the topical application of moisturizers may be considered.” Case series describing the clinical usefulness of topical agents in patients being treated with MTTs have been reported [3, 4]; however, there are no controlled studies.
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The usefulness of heparinoids, petrolatum, and urea, which are used as prescription moisturizers in Japan, has been reported for the treatment of both primary xerosis and xerosis caused by other diseases, drugs, and therapies; for example, dryness due to MTT treatment [4], radiation dermatitis associated with radiotherapy in patients with breast cancer [5, 6], and dryness and pruritus in patients on dialysis [7]. Prescribed moisturizers contribute to adherence to topical therapy because physicians, nurses, and pharmacists explain directly to the patients the necessity of moisturizers and how to apply them. Treatment of xerosis caused by cancer treatment tends to be neglected relative to the treatment of the underlying disease. However, the therapeutic effect of EGFR inhibitors is higher in patients who develop skin disorders [8, 9]. Therefore, the treatment of skin disorders conceivably contributes to the continuation of treatment with MTT. However, the current status of moisturizer use is unclear.
The purpose of this study was to analyze the utilization patterns and medical costs of moisturizers in patients treated with MTT, using a health insurance claims database.
Methods
This was a retrospective observational study using a commercial Medical Data Vision (MDV) database of secondary, unlinkable anonymized data; institutional review board approval was not required.
Data Source
We used the Japanese hospital-based claims database developed by Medical Data Vision Co., Ltd. (Tokyo, Japan) for our analyses. The MDV database comprises approximately 28 million patients from 400 hospitals in Japan that use the diagnosis-related-group-like fixed payment system, which is called the Diagnosis Procedure Combination (DPC) system in Japan. These hospitals account for 22% of all acute-phase hospitals and are widely distributed throughout Japan. The MDV database uses an anonymized patient identifier and stores the following patient information: sex, birth year, date of medical service, diagnosis codes, hospitalization, medical procedures, test orders, operations, and prescriptions.
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The source cohort in this study comprised patients who were prescribed any MTT (Online Resource 1) between April 2008 and April 2019 (n = 190,536) with continuous enrollment for at least 12 months.
The patient selection period was from October 2011 to April 2018. The follow-up period was 1 year from the index date, which was defined as the first prescription date of MTT, and the pre-index period was defined as the 6-month period before the index date. To investigate the use of moisturizers after completion of treatment with MTT, we defined the “washout period” (end of MTT treatment) as 56 days after the last use of MTT. The study cohort was determined by evaluating patients according to the inclusion and exclusion criteria.
Inclusion criteria:
Patients who were treated with the MTTs listed in Supplementary Table S1 during the patient selection period.
Exclusion criteria:
Patients to whom any of the following conditions applied:
not treated with the defined MTTs during the patient selection period;
prescribed at least one moisturizer (heparinoids, petrolatum, urea) within the pre-index period;
prescribed at least one MTT within the pre-index period;
not continuously observed in the database during the follow-up period (patients must have had at least one medical claim each quarter within the follow-up period);
age < 18 years at the index date; and
prescribed MTT drugs from more than one MTT category at the index date.
Patient Characteristics
The following patient characteristics data were collected:
age at the index date;
sex;
cancer type (International Classification of Diseases version 10 (ICD-10) codes: C00–C96);
type of MTT being used; and
type of moisturizer [Anatomical, Therapeutic, Chemical Classification (ATC) codes: C05B0 (heparinoid), V07A0 (petrolatum), and D02A0 (urea)].
Statistical Analysis
The following variables describing the use of moisturizers were analyzed using descriptive statistics:
number of days for which a patient was treated with MTT during the follow-up period;
total number of days for which a patient used moisturizers during the follow-up period, total amount (g) of prescribed moisturizers, and the number and proportion of patients who were prescribed moisturizers (by month);
total number of days for which a patient used moisturizers after the washout period, total amount (g) of prescribed moisturizers, and the number and proportion of patients who were prescribed moisturizers during the follow-up period;
whether treatment with radiotherapy was performed during the follow-up period (according to the presence of the management/implementation fee for radiotherapy, M001) and, if so, the number of days a patient received treatment; and
total medical costs 6 months and 12 months from the index date, and costs of outpatient visits, hospitalization, prescribed drugs, and radiotherapy (exchange rate of USD 1 = JPY 114.59 as of April 2019).
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Descriptive analyses were performed using standard descriptive statistics. For continuous variables, sample sizes (n), measures of central tendency (mean, median), and measures of variation (standard deviation, minimum, maximum, quartiles, and/or percentiles) are provided. For categorical variables, frequency tables containing sample sizes and proportions (%) for the different categories are presented. We also performed analyses stratified by heparinoids, petrolatum, and urea. All analyses were performed using SAS software version 9.3 (SAS Institute, Cary, NC, USA). Note that the number of prescription days for moisturizers was set at 28 days for each moisturizer prescription. If there were multiple prescriptions, and the interval between prescription dates was less than 28 days, the number of prescription days for the moisturizer was set to the number of days between prescription dates.
Results
Of 190,536 patients in the source cohort, 78,190 patients were included in the study cohort. Among the study cohort, 27,906 patients (35.7%) were prescribed moisturizers (Group M) and 50,284 patients (64.3%) were not prescribed moisturizers (Group N) (Fig. 1).
Fig. 1
Study flowchart. †Patients were excluded for several reasons; therefore, the sum of the excluded patients is greater than the total number of excluded patients. MTT molecular targeted therapy. Data extraction period: April 2008 to April 2019. Index date: date of the first MTT prescription. Selection period: October 2011 to April 2018. Follow-up period: 1 year from the index date
×
Patient Demographics
Table 1 presents the patients’ background characteristics, groups according to the use of moisturizers, and groups divided by the type of moisturizer (heparinoids, petrolatum, urea, and a combination of two or more moisturizers). When Group N (50,284 patients) was compared with Group M (27,906 patients), the proportion of men was slightly higher versus women (47.4% vs. 45.4%, respectively), and the mean age was also slightly higher (65.7 years versus 64.7 years, respectively) in Group M. Also in Group M, users of heparinoids accounted for 72.6% (n = 20,265) of the patients, petrolatum 14.2% (n = 3960), urea 10.6% (n = 2952), and a combination of moisturizers 2.6% (n = 729). Among the MTT groups with ≥ 1000 patients, the proportion of moisturizer users was highest in the EGFR inhibitor group (71.4%), followed by the multikinase inhibitor group (50.2%), and the immune checkpoint inhibitor group (42.1%), and lowest in the Janus kinase (JAK) inhibitor group (10.7%), BCR-ABL inhibitor group (15.4%), and anti-cluster of differentiation 20 (CD20) antibody group (23.2%) (Table 2).
Table 1
Baseline characteristics (at the index date) for the patient cohort
Overall
All (no moisturizer)
All (with moisturizer)
Heparinoid
Petrolatum
Urea
Combination
78,190
50,284
64.3%
27,906
35.7%
20,265
72.6%
3960
14.2%
2,952
10.6%
729
2.6%
Sex, n (%)
Male
36,041
46.1%
22,805
45.4%
13,236
47.4%
9588
47.3%
1841
46.5%
1481
50.2%
326
44.7%
Female
42,149
53.9%
27,479
54.7%
14,670
52.6%
10,677
52.7%
2119
53.5%
1471
49.8%
403
55.3%
Age
Mean (SD)
65.07 (12.25)
64.71 (12.50)
65.73 (11.76)
65.57 (11.67)
66.15 (12.34)
66.41 (11.47)
65.13 (12.05)
95% CI
64.99–65.16
64.60–64.82
65.59–65.87
65.41–65.73
65.77–66.54
65.99–66.82
64.26–66.01
Min, Max
18, 99
18, 98
18, 99
18, 97
18, 99
18, 94
18, 90
Median
67
66
67
67
68
68
66
Age category (years), n (%)
18–34
1358
1.7%
980
2.0%
378
1.4%
255
1.3%
78
2.0%
30
1.0%
15
2.1%
35–44
3970
5.1%
2726
5.4%
1244
4.5%
923
4.6%
168
4.2%
115
3.9%
38
5.2%
45–54
9099
11.6%
6102
12.1%
2997
10.7%
2212
10.9%
416
10.5%
302
10.2%
67
9.2%
55–64
18,552
23.7%
12,023
23.9%
6529
23.4%
4778
23.6%
866
21.9%
691
23.4%
194
26.6%
65–74
27,301
34.9%
17,144
34.1%
10,157
36.4%
7483
36.9%
1375
34.7%
1049
35.5%
250
34.3%
75–
17,910
22.9%
11,309
22.5%
6601
23.7%
4614
22.8%
1057
26.7%
765
25.9%
165
22.6%
SD standard deviation, CI confidence interval
Table 2
Number of patients and the proportion of moisturizer users by MTT group
Overall
All (no moisturizer)
All (with moisturizer)
Details of moisturizer
Heparinoid
Petrolatum
Urea
Combination
MTT group (at the index date), n (% of usage in the MTT group)
Among 78,190 patients who were treated with MTT, the most common cancer codes were C81–96 “malignant neoplasms, stated or presumed to be primary, of lymphoid, haematopoietic and related tissue” (34.7%), when codes C76–80 “malignant neoplasms of ill-defined, secondary and unspecified sites” were excluded (Supplementary Table S2). Moreover, when the types of cancer with ≥ 1000 patients (eight types) were compared, the proportion of moisturizer users in MTT group was high in patients with respiratory system (47.9%), digestive system (45.7%), or urinary system (45.6%) cancer and low in patients with breast (32.2%), female genital (27.2%), or lymphoid tissue (24.1%) cancer.
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Moisturizer Use
Number of Days Patients Were Treated with Anticancer Drugs (MTTs) during the Follow-Up Period
Regarding the number of days patients were treated with MTTs during the follow-up period, data were collected according to MTT category and were further divided into an oral drug group and an injectable drug group (Supplementary Table S3). In the EGFR inhibitor group, one of the groups in which the proportion of moisturizer users was the highest, moisturizer users had more treatment days for both oral drugs (252.1 ± 106.4 versus 225.5 ± 120.3, mean ± SD) and injectable drugs (11.9 ± 9.7 versus 9.0 ± 8.8, mean ± SD) compared with patients who did not use moisturizers. In both Group M and Group N, many anticancer drugs were prescribed for a different number of days. However, no consistent pattern was observed in the prescription length.
Total Number of Days for Which a Patient Used Moisturizers during the Follow-up Period, Total Amount (g) of Prescribed Moisturizers, and the Number and Proportion of Patients Who Were Prescribed Moisturizers by Month
The prescription length in days and the amount of moisturizers prescribed during the follow-up period are presented in Table 3. The mean amount of heparinoids (22,537 patients) administered was 393.6 g (median 150 g, Q1–Q3 60–430 g), and the mean prescription length was 92.2 days (median 56 days, Q1–Q3 28–127 days). The mean amount of petrolatum (6615 patients) administered was 127.8 g (median 50 g, Q1–Q3 20–100 g), and the mean prescription length was 48.5 days (median 28 days, Q1–Q3 28–56 days). The mean amount of urea formulations (4356 patients) administered was 174.4 g (median 80 g, Q1–Q3 40–200 g), and the mean prescription length was 70.3 days (median 47 days, Q1–Q3 28–84 days).
Table 3
Proportion of patients, quantity, and prescription days of heparinoids/petrolatum/urea in all patients receiving moisturizers
n (%)
Quantity (g)
Period (days)
Mean (SD)
Median
(Q1–Q3)
Mean (SD)
Median
(Q1–Q3)
Heparinoids
22,537
80.8%
393.6 (692.8)
150 (60–430)
92.2 (79.4)
56 (28–127)
Petrolatum
6615
23.7%
127.8 (304.5)
50 (20–100)
48.5 (42.3)
28 (28–56)
Urea
4356
15.6%
174.4 (293.5)
80 (40–200)
70.3 (64.4)
47 (28–84)
n number, SD standard deviation, Q1–Q3 first to third quartile
% indicates the percentage of the total number of patients receiving moisturizers calculated cumulatively from the index date up to the end of follow-up
For patients who were prescribed moisturizers, the timing of the start of the moisturizer prescription after the MTT prescription date and the number of patients who were prescribed moisturizers at each timepoint are shown in Supplementary Fig. S1. Moisturizers were prescribed for 31.5% of the patients within 1 month from the start of MTT prescriptions, for 74.0% within 6 months and 100% within 12 months. According to the inclusion criteria, patients whose prescriptions were started after the 12th month were not included in the study cohort.
Total Number of Days for Which a Patient Used Moisturizers after the Washout Period and the Total Amount (g) of Prescribed Moisturizers
The prescribed amount of each moisturizer and the prescription length in days after the washout period were calculated as during the follow-up period. The mean amount of heparinoids (3932 patients) administered was 213.5 g (median 100 g, Q1–Q3 50–250 g), and the mean prescription length was 53.1 days (median 31 days, Q1–Q3 28–67 days). The mean amount of petrolatum (1335 patients) administered was 135.5 g (median 50 g, Q1–Q3 20–100 g), and the mean prescription length was 39.4 days (median 28 days, Q1–Q3 28–43 days). The mean amount of urea formulations (657 patients) administered was 121.9 g (median 60 g, Q1–Q3 40–120 g), and the mean prescription length was 47.4 days (median 28 days, Q1–Q3 28–56 days).
Treatment with Radiotherapy during the Follow-up Period (Medical Remuneration Points and Management/Implementation Fee for Radiotherapy, Code: M001)
The number of patients treated with radiotherapy during the follow-up period and the number of days for which patients received treatment are presented in Supplementary Table S4. In the study cohort, 10.0% of the patients (7801 patients) received concomitant radiotherapy, and the mean length of treatment was 22.8 days (median 20 days, Q1–Q3 15–26 days). The proportion of moisturizer users was higher in patients who received radiotherapy than in those who did not receive radiotherapy.
Total Medical Costs 6 Months and 12 Months from the Index Date, and the Costs of Outpatient Visits, Hospitalization, Drugs (MTTs, Other Drugs, and Moisturizers), and Radiotherapy
When the total medical costs of cancer treatment were calculated by item over the 6-month and 12-month periods after the index date, medical costs for Group M were higher than for Group N by USD 4078 (USD 32,866 versus 28,788; JPY 0.467 million, 3.766 million versus 3.299 million) at 6 months and USD 8983 (USD 53,797 versus 44,814; JPY 1.029 million, 6.165 million versus 5.135 million) at 12 months (Table 4; USD, Supplementary Table S5; JPY). In Group M, the moisturizer cost was USD 35 ± 65 (JPY 4008 ± 7453, mean ± SD) at 6 months and USD 53 ± 108 (JPY 6033 ± 12,344, mean ± SD) at 12 months, which accounted for approximately 0.1% of the total medical costs. The moisturizer costs accounted for 0.86% of the difference between the two groups at 6 months and 0.59% at 12 months.
Table 4
Cost (in USD) analysis during the first 6 months of follow-up and for the entire 12 months of follow-up
Group N
Group M
n
Mean
(SD)
95% CI
% of total medical costs
n
Mean
(SD)
95% CI
% of total medical costs
First 6 months of follow-up
Total medical costs
50,284
28,788
(18,061)
28,630–28,945
27,906
32,866
(20,222)
32,629–33,104
Outpatient costs
49,598
18,556
(15,097)
18,423–18,689
64.5%
27,246
18,220
(15,398)
18,037–18,403
55.4%
Inpatient costs
32,117
16,415
(17,007)
16,229–16,601
57.0%
20,912
20,120
(20,889)
19,837–20,403
61.2%
Defined MTT costs
50,284
16,541
(14,113)
16,418–16,665
57.5%
27,906
16,689
(14,536)
16,518–16,859
50.8%
Moisturizer costs
0
–
–
20,656
35
(65)
34–36
0.1%
Other drug costs
49,564
5434
(6788)
5374–5494
18.9%
27,864
6500
(7709)
6409–6590
19.8%
Radiotherapy costs
2893
2351
(1259)
2305–2397
8.2%
2176
2398
(1406)
2339–2458
7.3%
Entire 12 months of follow-up
Total medical costs
50,284
44,814
(29,634)
44,555–45,073
100.0%
27,906
53,797
(32,183)
53,419–54,174
100.0%
Outpatient costs
50,175
30,856
(26,524)
30,624–31,088
68.9%
27,774
31,358
(25,857)
31,054–31,662
58.3%
Inpatient costs
34,939
20,185
(22,313)
19,951–20,419
45.0%
22,995
27,411
(29,834)
27,026–27,797
51.0%
Defined MTT costs
50,284
25,838
(24,192)
25,627–26,050
57.7%
27,906
26,872
(23,761)
26,593–27,151
50.0%
Moisturizer costs
0
–
–
27,906
53
(108)
51–54
0.1%
Other drug costs
49,808
8551
(11,271)
8452–8650
19.1%
27,898
10,880
(12,825)
10,730–11,031
20.2%
Radiotherapy costs
4284
2478
(1321)
2438–2517
5.5%
3517
2525
(1449)
2477–2573
4.7%
SD standard deviation, CI confidence interval, MTT molecular targeted therapy
.
We observed an increasing trend in both the proportion of moisturizer users and the amount of moisturizer used per patient over time (Supplementary Table S6).
Overall, changes in the proportion of moisturizer users over time in the MTT groups with ≥ 1000 patients showed a continuous year-to-year increase (Supplementary Fig. S2).
Discussion
Nationwide Estimation of the Number of Patients Receiving MTT
As of 2019, the MDV database covered 22% of acute-phase medical institutions in the DPC system in Japan. Provided that all patients with cancer are seen at acute-phase medical institutions, we estimate that approximately 870,000 cancer patients were treated with MTT during the follow-up period in this study [the number of patients included as the source cohort (190,536) divided by 0.22]. The Ministry of Health, Labour, and Welfare in Japan estimated that, as of 2017, there were 1,782,000 patients with cancer. Considering that most anticancer drugs developed since 2000 are MTTs, “patients treated with MTT” who were included in our study cohort are expected to account for a large proportion of patients with cancer.
Moisturizer Utilization Pattern
The proportion of patients prescribed moisturizers was 35.7% among patients prescribed MTT during the study period. The proportion varied greatly among the MTT groups. The proportion of moisturizer users was the highest in the EGFR inhibitor group (71.4%) followed by the multikinase inhibitor group (50.2%), immune checkpoint inhibitor group (42.1%), and VEGF inhibitor group (40.2%). The proportion of users was low in the anti-CD20 antibody group (23.2%) and BCR-ABL inhibitor group (15.4%). The proportion of moisturizer users over time showed an increasing trend (31.6% in 2011 to 39.1% in 2018), and the proportion of moisturizer users in the EGFR inhibitor group increased from 53.5% to 74.7% during the same period. Moreover, in the 2018 data, the proportion of moisturizer users in the BCR-ABL inhibitor group, which was the lowest among the MTT groups, reached 21.1%. These findings suggest that moisturizer use has become common, not only with the use of EGFR inhibitors, which commonly cause skin disorders owing to their mechanisms of action, but also with the use of other anticancer drugs, where the mechanism by which they cause skin disorders is unclear. The proportion of EGFR inhibitors among the MTT groups actually decreased (13.8% in 2012 to 5.8% in 2018), which suggests that the increasing trend in moisturizer use was not caused by changes in the type of MTT being prescribed.
Variations in the Moisturizer Utilization Pattern
In Group M, 31.5% of the patients were prescribed moisturizers within 1 month after beginning MTT. However, the start of prescriptions was not limited to a certain period. Frequent symptoms of skin disorder differ depending on the MTT. Symptoms such as acneiform folliculitis peaked approximately 2 weeks after beginning MTT, while other symptoms, such as xerosis and paronychia, mainly developed after 28 days or later [10, 11]. These findings suggest that variable timing of initiating moisturizer use in the present analysis reflects variable timing in the onset of skin disorders.
Overall Budget Impact of Moisturizers
When drugs were compared according to their unit prices, there was a large difference between moisturizers and MTTs. Therefore, when we evaluated medical costs and drug costs per patient, the contribution of moisturizer costs was small. Specifically, the analysis of total medical costs at 6 months and 12 months showed that the difference in medical costs between Group M and Group N was USD 4078 (JPY 0.467 million) at 6 months and USD 8983 (JPY 1.029 million) at 12 months. However, the difference in moisturizer costs was USD 35 (JPY 4008) at 6 months and USD 53 (JPY 6033) at 12 months, which accounted for 0.1% of the total medical costs and only 0.59% in the difference in the total costs at 12 months.
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The total medical costs for users of anticancer drugs in Japan, calculated by dividing the total medical costs of users of anti-cancer drugs in the MDV database by 22%, which is the patient coverage of this database, was USD 17.1 billion (JPY 1.96 trillion; 1.174 trillion for non-users of moisturizers and 0.782 trillion for users); moisturizer costs accounted for USD 6.63 million (JPY 760 million). Therefore, conceivably, the medical costs of prescribed moisturizers in cancer treatment is extremely low. The main factors causing the high medical costs in Group M were extended hospitalization and increased costs of drugs other than moisturizers.
Limitations
The present study used commercially available claims data from DPC hospitals and did not capture treatments performed in non-DPC hospitals or clinics. In addition, nonprescription moisturizers such as over-the-counter moisturizers were not included. Follow-up of patients who were transferred to other medical institutions during treatment was also not possible. In Japan, unlike in other countries, the availability of a health insurance claims database at the national level is extremely limited. However, some drug utilization studies using commercially available claims data have been reported despite the limitations [12‐14]. We expect that similar analyses will be performed in the future using a broader database, to improve the generalizability of the findings in this study, if such a database becomes available.
The present study was not a comprehensive analysis of cancer treatment. We analyzed only patients with cancer who were prescribed MTT. Some MTTs, for example, EGFR inhibitors, are expected to cause skin disorders frequently because of their mechanisms of action. Therefore, the need for moisturizers in patients receiving MTT is higher than for patients receiving other anticancer drugs, which was why patients receiving MTT were chosen as the first cohort. However, because cytotoxic anticancer drugs can also cause skin disorders as an adverse event, broader studies analyzing patients receiving a wide variety of anticancer drugs are desirable.
Dermatological diagnoses caused by MTTs could not be identified because this database does not contain relationships between diagnoses and prescribed drugs. When we selected the patients for this study cohort from the source cohort, we excluded patients who were prescribed moisturizers before initiating MTT. This criterion was set to exclude the use of moisturizers to treat skin disorders not caused by anticancer drugs. However, this criterion also excluded patients prescribed moisturizers prophylactically and those who were already being treated with other anticancer drugs and who were prescribed moisturizers for skin disorders. Because of the stricter inclusion/exclusion criteria we set to identify only patients strongly associated with skin disorders caused by MTT, we expect that the number of patients using moisturizers in clinical practice is higher.
Conclusion
In this study, we analyzed moisturizer use in patients treated with MTT, using a commercially available claims database. The proportion of patients treated with MTT who used moisturizers was 35.7%, and the proportion varied among the MTT groups. The proportion of patients who were prescribed moisturizers increased over time. We also saw variations in the prescription length in days and the amount of moisturizers prescribed. Thus, we believe that moisturizers were used according to each patient’s condition.
Regarding the medical costs required for MTT treatment, the medical costs in Group M were higher than for Group N by USD 8983 (JPY 1.029 million) at 12 months. However, most of the costs resulted from costs not related to the moisturizer costs (e.g., costs for hospitalization and other drugs). The difference in costs that can be associated with moisturizers was USD 53 (approximately JPY 6000). Moisturizers accounted for 0.59% of the difference in the total medical costs in Group N and 0.1% of the total medical costs. We determined that the cost and use of moisturizers may contribute to continuation of MTT treatment.
Acknowledgements
Funding
This study and the Rapid Service Fee were funded by Maruho Co., Ltd.
Medical Writing, Editorial, and Other Assistance
Language editing assistance was provided by ASCA Corporation, funded by Maruho Co., Ltd.
Authorship
All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work as a whole, and have given their approval for this version to be published.
Author Contributions
All authors contributed to the study conception and design. Statistical analyses were performed by Yoshie Onishi and Anastasiia Motrunich. The first draft of the manuscript in Japanese was written by Ataru Igarashi and Yoshio Kiyohara. All authors read and approved the final manuscript.
Disclosures
Creativ-Ceutical K.K., Tokyo, Japan was paid to conduct the study. Ataru Igarashi and Yoshio Kiyohara received lecture/consultation fees from Maruho Co., Ltd.; Anastasiia Motrunich and Yoshie Onishi are employee of Creativ-Ceutical.; Akira Kanakubo and Momoyo Kishida are employees of Maruho Co., Ltd.; Lida Teng and Toshiya Matsuzaki have nothing to disclose.
Compliance with Ethics Guidelines
MDV database is comprised of secondary, unlikable anonymized data, institutional review board approval was not required in the study.
Data Availability
Not available because the datasets are commercial data of Medical Data Vision, Co., Ltd.
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