UMIN-CTR Clinical Trial

Unique ID issued by UMIN UMIN000061803
Receipt number R000070722
Scientific Title The Impact of Hospital Surgical Volumes on Short-Term Outcomes Following Brain Tumor Surgery from a Nationwide Database in Japan
Date of disclosure of the study information 2026/06/05
Last modified on 2026/06/04 20:09:47

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Basic information

Public title

The Impact of Hospital Surgical Volumes on Short-Term Outcomes Following Brain Tumor Surgery from a Nationwide Database in Japan

Acronym

The Impact of Hospital Surgical Volumes on Short-Term Outcomes Following Brain Tumor Surgery from a Nationwide Database in Japan

Scientific Title

The Impact of Hospital Surgical Volumes on Short-Term Outcomes Following Brain Tumor Surgery from a Nationwide Database in Japan

Scientific Title:Acronym

The Impact of Hospital Surgical Volumes on Short-Term Outcomes Following Brain Tumor Surgery from a Nationwide Database in Japan

Region

Japan


Condition

Condition

Central Nervous System Tumors

Classification by specialty

Neurosurgery

Classification by malignancy

Malignancy

Genomic information

NO


Objectives

Narrative objectives1

The literature suggests that patients with brain tumors show better prognoses when treated at hospitals with high surgical volumes, and this is considered one of the key factors contributing to favorable outcomes. However, previous studies have primarily focused on estimating conditional effects, and to the best of our knowledge, there are no reports estimating the average causal effect within the population when surgical volume is treated as an intervention variable. In this study, we will conduct an epidemiological study using the DPC (Diagnosis Procedure Combination) database-a nationwide database in Japan-and a methodology called "Target Trial Emulation", which simulates an ideal randomized controlled trial (target trial). The objective of this study is to estimate the causal effect between intervention strategies that altering the number of brain tumor surgeries performed at medical institutions and short-term postoperative outcomes for brain tumors by clearly defining ideal trial conditions and emulating them using observational study data.

Basic objectives2

Others

Basic objectives -Others

In-hospital mortality, mortality within 30 days of surgery and unscheduled readmission within 30 days of surgery.

Trial characteristics_1

Exploratory

Trial characteristics_2


Developmental phase

Not applicable


Assessment

Primary outcomes

In-hospital mortality

Key secondary outcomes

30-day postoperative mortality and unscheduled readmissions within 30 days of surgery


Base

Study type

Observational


Study design

Basic design


Randomization


Randomization unit


Blinding


Control


Stratification


Dynamic allocation


Institution consideration


Blocking


Concealment



Intervention

No. of arms


Purpose of intervention


Type of intervention


Interventions/Control_1


Interventions/Control_2


Interventions/Control_3


Interventions/Control_4


Interventions/Control_5


Interventions/Control_6


Interventions/Control_7


Interventions/Control_8


Interventions/Control_9


Interventions/Control_10



Eligibility

Age-lower limit


Not applicable

Age-upper limit


Not applicable

Gender

Male and Female

Key inclusion criteria

1. Observation period: Patients who (1) have DPC data for hospitalizations between April 2018 and March 2023, based on the date of discharge; (2) underwent specific surgeries for brain tumors (defined by seven types of K-codes: K1691, K1692, K154-3, K169-2, K 169-3, K 171-22, K171-21) during the observation period; (3) classified under ICD-10 codes Cxx and Dxx, which indicate neoplasms (tumors); (4) were all ages.

Key exclusion criteria

None. (We will cope with multiple imputation for missing value of covariates in analysis.)

Target sample size

27000


Research contact person

Name of lead principal investigator

1st name Atsushi
Middle name
Last name Goto

Organization

Yokohama City University Graduate School of Medicine

Division name

Department of Public Health

Zip code

236-0004

Address

3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan

TEL

045-787-2610

Email

agoto@yokohama-cu.ac.jp


Public contact

Name of contact person

1st name Chihiro
Middle name
Last name Oka

Organization

Yokohama City University Graduate School of Medicine

Division name

Department of Public Health

Zip code

236-0004

Address

3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan

TEL

045-787-2610

Homepage URL


Email

oka.chi.ld@yokohama-cu.ac.jp


Sponsor or person

Institute

Yokohama City University

Institute

Department

Personal name



Funding Source

Organization

Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellows (JSPS Research Fellow)

Organization

Division

Category of Funding Organization

Japanese Governmental office

Nationality of Funding Organization

Japan


Other related organizations

Co-sponsor


Name of secondary funder(s)

Children's Cancer Association of Japan


IRB Contact (For public release)

Organization

The Ethics Committee of the School of Medicine, Yokohama City University

Address

3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan

Tel

045-370-7627

Email

rinri@yokohama-cu.ac.jp


Secondary IDs

Secondary IDs

NO

Study ID_1


Org. issuing International ID_1


Study ID_2


Org. issuing International ID_2


IND to MHLW



Institutions

Institutions



Other administrative information

Date of disclosure of the study information

2026 Year 06 Month 05 Day


Related information

URL releasing protocol


Publication of results

Unpublished


Result

URL related to results and publications


Number of participants that the trial has enrolled


Results


Results date posted


Results Delayed


Results Delay Reason


Date of the first journal publication of results


Baseline Characteristics


Participant flow


Adverse events


Outcome measures


Plan to share IPD


IPD sharing Plan description



Progress

Recruitment status

Preinitiation

Date of protocol fixation

2026 Year 06 Month 04 Day

Date of IRB

2025 Year 11 Month 21 Day

Anticipated trial start date

2026 Year 06 Month 05 Day

Last follow-up date

2026 Year 06 Month 06 Day

Date of closure to data entry


Date trial data considered complete


Date analysis concluded



Other

Other related information

The objective of this study is to conduct a retrospective observational study using DPC (Diagnosis-Procedure Combination). The study population consists of patients who underwent specific brain tumor surgeries between April 1, 2018, and March 31, 2023.
"Exposure" refers to the number of surgeries performed in the previous year at the facility where each patient underwent surgery. The study population and exposure are defined by age and the K code for the surgical procedure. Within each patient cohort, participants are classified according to the following intervention strategies:
Interventions involving surgery at hospitals with 1) zero percentile or higher, 2) 25th percentile or higher, or 3) 50th percentile or higher, or 4) 75th percentile or higher in the number of surgeries performed.
The primary outcome is in-hospital death after surgery, and we will estimate changes in the cumulative incidence rate.


Management information

Registered date

2026 Year 06 Month 04 Day

Last modified on

2026 Year 06 Month 04 Day



Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000070722