Is cumulative number of clinical trial registrations on UMIN-CTR changed since the new clinical trial act of Japan was enfoced?

Read UMIN-CTR newest dataset.

Read the newest snapshot of UMIN-CTR, and slice to the interventional study which starts within recent 5 years.(after Jan 1 2013)

library(readr)
ctr <- read_csv("https://upload.umin.ac.jp/ctr_csv/ctr_data_j.csv.gz")
## Warning: Missing column names filled in: 'X116' [116]
## Warning: Duplicated column names deduplicated: '試験名/Official
## scientific title of the study' => '試験名/Official scientific title of the
## study_1' [4], '試験簡略名/Title of the study (Brief title)' => '試験簡略
## 名/Title of the study (Brief title)_1' [6], '対象疾患名/Condition' => '対象
## 疾患名/Condition_1' [9], '目的1/Narrative objectives1' => '目的1/Narrative
## objectives1_1' [14], '目的2 -その他詳細/Basic objectives -Others' => '目
## 的2 -その他詳細/Basic objectives -Others_1' [17], '主要アウトカム評価項目/
## Primary outcomes' => '主要アウトカム評価項目/Primary outcomes_1' [22], '副
## 次アウトカム評価項目/Key secondary outcomes' => '副次アウトカム評価項目/
## Key secondary outcomes_1' [24], '介入1/Interventions/Control_1' => '介入1/
## Interventions/Control_1_1' [40], '介入2/Interventions/Control_2' => '介入
## 2/Interventions/Control_2_1' [42], '介入3/Interventions/Control_3' => '介
## 入3/Interventions/Control_3_1' [44], '介入4/Interventions/Control_4' => '介
## 入4/Interventions/Control_4_1' [46], '介入5/Interventions/Control_5' => '介
## 入5/Interventions/Control_5_1' [48], '介入6/Interventions/Control_6' => '介
## 入6/Interventions/Control_6_1' [50], '介入7/Interventions/Control_7' => '介
## 入7/Interventions/Control_7_1' [52], '介入8/Interventions/Control_8' => '介
## 入8/Interventions/Control_8_1' [54], '介入9/Interventions/Control_9' =>
## '介入9/Interventions/Control_9_1' [56], '介入10/Interventions/Control_10'
## => '介入10/Interventions/Control_10_1' [58], '選択基準/Key inclusion
## criteria' => '選択基準/Key inclusion criteria_1' [63], '除外基準/Key
## exclusion criteria' => '除外基準/Key exclusion criteria_1' [65], '研究費
## 拠出国/Nationality of Funding Organization' => '研究費拠出国/Nationality
## of Funding Organization_1' [77], '共同実施組織/Co-sponsor' => '共同実施
## 組織/Co-sponsor_1' [79], 'その他の研究費提供組織/Name of secondary funｄ
## er(s)' => 'その他の研究費提供組織/Name of secondary funｄer(s)_1' [81], 'ID
## 発行機関1/Org. issuing International ID_1' => 'ID発行機関1/Org. issuing
## International ID_1_1' [85], 'ID発行機関2/Org. issuing International ID_2'
## => 'ID発行機関2/Org. issuing International ID_2_1' [88], '主な結果/Results'
## => '主な結果/Results_1' [103], 'その他関連情報/Other related information'
## => 'その他関連情報/Other related information_1' [105], '登録日時/Registered
## date' => '登録日時/Registered date_1' [111], '登録日時/Registered date' =>
## '登録日時/Registered date_2' [113], '登録日時/Registered date' => '登録日
## 時/Registered date_3' [115]
## Parsed with column specification:
## cols(
##   .default = col_character(),
##   `群数/No. of arms` = col_integer(),
##   `目標参加者数/Target sample size` = col_integer(),
##   `一般公開日（本登録希望日）/Date of disclosure of the study information` = col_date(format = ""),
##   `プロトコル確定日/Date of protocol fixation` = col_date(format = ""),
##   `登録・組入れ開始（予定）日/Anticipated trial start date` = col_date(format = ""),
##   `フォロー終了(予定)日/Last follow-up date` = col_date(format = ""),
##   `入力終了(予定)日/Date of closure to data entry` = col_date(format = ""),
##   `データ固定（予定）日/Date trial data considered complete` = col_date(format = ""),
##   `解析終了(予定)日/Date analysis concluded` = col_date(format = ""),
##   `登録日時/Registered date` = col_date(format = ""),
##   `最終更新日/Last modified on` = col_date(format = ""),
##   `登録日時/Registered date_1` = col_date(format = ""),
##   `登録日時/Registered date_3` = col_date(format = "")
## )
## See spec(...) for full column specifications.
## Warning: 2 parsing failures.
## row # A tibble: 2 x 5 col     row col                expected  actual   file                         expected   <int> <chr>              <chr>     <chr>    <chr>                        actual 1 15914 目標参加者数/Target sam… an integ… 9999999… 'https://upload.umin.ac.jp/… file 2 22753 目標参加者数/Target sam… an integ… 9999999… 'https://upload.umin.ac.jp/…
ctr$bdate <- as.Date(ctr$`登録・組入れ開始（予定）日/Anticipated trial start date` , format="%Y年%m月%d日", TZ="Asia/Tokyo")
ctr$isObserv <- ctr$`試験の種類/Study type` == "観察/Observational" # 「介入・観察」は「介入」と扱う
ctrd <- subset(ctr, isObserv==FALSE & bdate >= as.Date("2013-01-01"))

Plot the number of trials by its start month.

The new clinical trial act was enforced on Apr 1, 2018 (dashed vertical line). All clinical trials of pharmaceuticals that starts after Apr 1 should be registered to the new CTR(jRCT), not UMIN-CTR. Duplicated registration is prohibited, so the number of UMIN-CTR’s registrations will be reduced much after the April.

hist(ctrd$bdate, breaks="months", ylab="Number of Registrations", ylim=c(0, 500),format="%Y-%m", freq=TRUE,axes=FALSE, main="Number of newly started researches per month at UMIN-CTR", xlab="Research start date")
axis(2, seq(0,500,by=100))
axis.Date(1, (seq(as.Date("2013-01-01"), as.Date("2019-01-01"), by="year")), format="%Y-%m")
abline(h=seq(100,500,by=50), lty="dotted")
abline(v=as.numeric(seq(as.Date("2013-01-01"), as.Date("2019-01-01"), by="year")), lty="dotted")
abline(v=as.numeric(as.Date("2018-04-01")),lty="dashed")

Number of registered trials that was started after April 1, 2018 is much reduced as expected.

What is proportion of English-only registrations?

UMIN-CTR requests English registration for each CTR. Optionally, for the trials that will recruit participants in Japan, UMIN-CTR requests Japanese registration. So inspect current proportion of English-only entries.

# extract entries with no Official title and Brief title were given in Japanese.
englishonly <- (is.na(ctr$`試験名/Official scientific title of the study`) & is.na(ctr$`試験簡略名/Title of the study (Brief title)`) & !is.na(ctr$`試験名/Official scientific title of the study_1`) & !is.na(ctr$`試験簡略名/Title of the study (Brief title)_1`))

Total number of registration in UMIN-CTR is 34406. Currently 455 entries have no information in Japanese. This is 0.01 % of total number of registrations.

So what is the characteristics of English-only entries? Let’s try aggregating by geographic region.

ctr_eo <- ctr[englishonly,]
knitr::kable(table(ctr_eo$`試験実施地域/Region`))
Var1 Freq
アジア（日本以外）/Asia(except Japan): 185
アジア（日本以外）/Asia(except Japan):欧州/Europe: 2
アフリカ/Africa: 54
オセアニア/Australia: 1
欧州/Europe: 68
南米/South America: 16
日本/Japan: 64
日本/Japan:アジア（日本以外）/Asia(except Japan): 3
日本/Japan:アジア（日本以外）/Asia(except Japan):北米/North America:オセアニア/Australia:欧州/Europe: 1
日本/Japan:アジア（日本以外）/Asia(except Japan):北米/North America:南米/South America:オセアニア/Australia:欧州/Europe:アフリカ/Africa: 2
北米/North America: 57
北米/North America:オセアニア/Australia: 1
北米/North America:南米/South America:オセアニア/Australia:欧州/Europe: 1

Asia(except Japan) , Europe trials tend to be registered in English only. 56 trials were registered in English only though their region is Japan only.

How is the trend of proportion of Observational Studies in UMIN-CTR?

ctrd <- subset(ctr, bdate >= as.Date("2013-01-01"))
hmax <- 12*(2019-2013)
ctrdo <- subset(ctrd, isObserv==TRUE)

ratmonth <- seq(as.Date("2013-01-01"), as.Date("2019-01-01"), by="month")
numrat <-t(as.matrix(sapply(1:length(ratmonth), function(x) { if(x == 1) return(0) ; sum(ctrdo$bdate < ratmonth[x] & ctrdo$bdate >= ratmonth[x-1] ) / sum(ctrd$bdate < ratmonth[x] & ctrd$bdate >= ratmonth[x-1])})))
colnames(numrat) <- format(ratmonth, "%Y-%m")
caxis <- colnames(numrat)
caxis[ (1:length(caxis))%% 12 != 1 ] <- ""
barplot(numrat, ylab="Proportion of observational studies", space=c(0,0), ylim=c(0, 0.4),axes=FALSE, axisnames=FALSE, col="gray", border=FALSE, main="Proportion of observational studies among all started studies per month", xlab="Date")
## Warning in space + width: 長いオブジェクトの長さが短いオブジェクトの長さの
## 倍数になっていません

## Warning in space + width: 長いオブジェクトの長さが短いオブジェクトの長さの
## 倍数になっていません
axis(2, seq(0,1,by=0.1))
axis(1, grep("-01",caxis), caxis[grep("-01",caxis)])
abline(h=seq(0,1,by=0.1), lty="dotted")
abline(v=seq(13,hmax+1,by=12), lty="dotted")

Proportion of observed studies that begin after Apr 2018 is slightly increased then previous trend.