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Featured researches published by Momoko Iwamoto.


Cancer Epidemiology | 2014

Estimated life expectancy and risk of death from cancer by quartiles in the older Japanese population: 2010 vital statistics

Momoko Iwamoto; Fumiaki Nakamura; Takahiro Higashi

Data on life expectancies and risk of death from cancer are essential information to have when making informed decisions about cancer screening and treatment options, but has never been presented in a way that is readily available to use for physicians in Japan. We provided estimates of life expectancies and predicted risk of death from seven most common types of cancer (lung, gastric, liver, colon, prostate, breast, and cervical) by quartiles for the older Japanese population above 50 years old, using 2010 life tables and cancer mortality statistics data. We found that there was a large difference in life expectancy between older persons in the upper and lower quartiles. Risk of death from breast cancer was low. By using this data, physicians can more accurately obtain life expectancy estimates by assessing which quartile the patient is most likely to fall under, and help patients make better informed decisions.


Cancer Science | 2016

Monitoring and evaluating the quality of cancer care in Japan using administrative claims data

Momoko Iwamoto; Fumiaki Nakamura; Takahiro Higashi

The importance of measuring the quality of cancer care has been well recognized in many developed countries, but has never been successfully implemented on a national level in Japan. We sought to establish a wide‐scale quality monitoring and evaluation program for cancer by measuring 13 process‐of‐care quality indicators (QI) using a registry‐linked claims database. We measured two QI on pre‐treatment testing, nine on adherence to clinical guidelines on therapeutic treatments, and two on supportive care, for breast, prostate, colorectal, stomach, lung, liver and cervical cancer patients who were diagnosed in 2011 from 178 hospitals. We further assessed the reasons for non‐adherence for patients who did not receive the indicated care in 26 hospitals. QI for pretreatment testing were high in most hospitals (above 80%), but scores on adjuvant radiation and chemoradiation therapies were low (20–37%), except for breast cancer (74%). QI for adjuvant chemotherapy and supportive care were more widely distributed across hospitals (45–68%). Further analysis in 26 hospitals showed that most of the patients who did not receive adjuvant chemotherapy had clinically valid reasons for not receiving the specified care (above 70%), but the majority of the patients did not have sufficient reasons for not receiving adjuvant radiotherapy (52–69%) and supportive care (above 80%). We present here the first wide‐scale quality measurement initiative of cancer patients in Japan. Patients without clinically valid reasons for non‐adherence should be examined further in future to improve care.


Cancer Epidemiology | 2015

A national profile of the impact of parental cancer on their children in Japan

Izumi Inoue; Takahiro Higashi; Momoko Iwamoto; Sue P. Heiney; Tomohiro Tamaki; Kaori Osawa; Miho Inoue; Keiko Shiraishi; Rebekah Kojima; Motohiro Matoba

OBJECTIVE Dependent children under the age of 18 are particularly vulnerable to the stress of parental death from cancer or of having a parent diagnosed and treated for the disease. More and more Japanese couples are postponing parenthood, which increases their chances of developing cancer while they still have a dependent child. However, the problem has not received enough attention from healthcare professionals and policy-makers because the extent and breadth of the problem has never been examined in the Japanese population. Therefore, we aimed to estimate the nationwide incidence of cancer patients who have children under the age of 18 years, as well as the incidence of children who have a parent diagnosed with cancer in Japan. STUDY DESIGN We calculated the proportion of patients who have children stratified by age, gender and cancer type using electronic medical records of cancer patients (20-59 years old) admitted to the National Cancer Center Hospital (NCCH) for the first time between January 2009 and December 2013. We projected these estimates onto the Japanese population using 2010 population-based cancer registry data, and repeated the projection using 2011 hospital-based cancer registry data so that estimates of patients receiving care at Designated Cancer Care (DCC) hospitals could be obtained. RESULTS We found that an estimated 56,143 cancer patients who have 87,017 dependent children are diagnosed with cancer every year in Japan. The proportion of children in Japan who had a parent newly diagnosed with cancer in 2010 was approximately 0.38%. We estimated that in 2011 there were on average about 82 cancer patients with minor children and 128 minor children who have at least one parent diagnosed with cancer in every DCC hospital in Japan. CONCLUSION Parental cancer is common. We have identified that many adults diagnosed with cancer have the double burden of coping with the diagnosis and treatment as well as supporting their children through this experience. Additional data on socioeconomic characteristics and needs assessment of these patients are required to understand how best to help children and families cope with cancer.


Journal of Radiation Research | 2016

Patterns of prescribing radiotherapy and bevacizumab in nationwide practice – analysis of 101 designated cancer care hospitals in Japan

Yoichiro Tsukada; Fumiaki Nakamura; Momoko Iwamoto; Atsuro Terahara; Takahiro Higashi

Radiotherapy and bevacizumab are each effective in treating patients with advanced cancer, but their concurrent use may cause serious adverse events (SAEs). Whereas sequential administration can theoretically reduce the risk of SAEs while maintaining the anticancer effects, this hypothesis remains unconfirmed, leading to variations in practice. To elucidate current practices, the patterns of care received by patients in Japan with regard to these two therapies were assessed in a large database of a hospital-based cancer registry linked with insurance claims. This database contained information on 106 057 patients diagnosed with seven major cancers in 2011 and the care they received up to the end of 2012. In total, 335 patients from 101 hospitals in the database were treated with both radiotherapy and bevacizumab. Of these patients, 50.8% had lung cancer, and 51.3% had Stage IV cancer. Of the 335 patients, 75 (22.4%) received these therapies concurrently. In patients treated sequentially, the time from the last dose of bevacizumab to the start of radiotherapy was most frequently 4–5 weeks (12.4%), whereas the time from the end of radiotherapy to the start of bevacizumab was most frequently 1–2 weeks (10.6%). The cumulative proportions of patients in these two groups receiving sequential therapies within 3 weeks were 19.0% and 26.1%, respectively. Many practices appeared to avoid the concurrent use of bevacizumab and radiation, but some provided concurrent therapy. Additional data are required to determine whether the avoidance of concurrent use should become a standard of care.


Japanese Journal of Clinical Oncology | 2015

Accuracy of using Diagnosis Procedure Combination administrative claims data for estimating the amount of opioid consumption among cancer patients in Japan

Momoko Iwamoto; Takahiro Higashi; Hiroki Miura; Takahiro Kawaguchi; Shigeyuki Tanaka; Itsuku Yamashita; Tetsusuke Yoshimoto; Shigeaki Yoshida; Motohiro Matoba

OBJECTIVE The state of opioid consumption among cancer patients has never been comprehensively investigated in Japan. The Diagnosis Procedure Combination claims data may be used to measure and monitor opioid consumption among cancer patients, but the accuracy of using the Diagnosis Procedure Combination data for this purpose has never been tested. METHODS We aimed to ascertain the accuracy of using the Diagnosis Procedure Combination claims data for estimating total opioid analgesic consumption by cancer patients compared with electronic medical records at Aomori Prefectural Central Hospital. We calculated percent differences between estimates obtained from electronic medical records and Diagnosis Procedure Combination claims data by month and drug type (morphine, oxycodone, fentanyl, buprenorphine, codeine and tramadol) between 1 October 2012 and 30 September 2013, and further examined the causes of discrepancy by reviewing medical and administrative charts between April and July 2013. RESULTS Percent differences varied by month for drug types with small prescription volumes, but less so for drugs with larger prescription volumes. Differences also tended to diminish when consumption was compared for a year instead of a month. Total percent difference between electronic medical records and Diagnosis Procedure Combination data during the study period was -0.1% (4721 mg per year per hospital), as electronic medical records as baseline. Half of the discrepancy was caused by errors in data entry. CONCLUSION Our study showed that Diagnosis Procedure Combination claims data can be used to accurately estimate opioid consumption among a population of cancer patients, although the same conclusion cannot be made for individual estimates or when making estimates for a group of patients over a short period of time.


Journal of Clinical Oncology | 2017

Quality indicators for cervical cancer care in Japan.

Tomone Watanabe; Satoru Kamitani; Momoko Iwamoto; Takahiro Higashi

219Background: Although ensuring high-quality care has a central role in Japanese cancer policy, introduction of a system to evaluate quality is still underway. With the goal of establishing a sustainable measurement system, this study assesses adherence to quality indicators (QIs) as an index for evaluating the quality of care for cervical cancer patients in Japan. Methods: Ten measurable QIs were devised by an expert committee using the modified Delphi method. Adherence to each QI was calculated by using hospital cancer registry data of patients diagnosed during 2013 and claims data between October 1, 2012, and December 31, 2014. Using registry-linked claims data across 281 hospitals, we measured 3 QIs on treatment for CIN3, 3 QIs on stage III or IVA, and 1 QI on stage IVB, respectively. We also measured 1 QI on examination of cancer spread and 1 QI on brachytherapy. Results: Data for 11,925 cervical cancer patients were analyzed. Patients’ mean age was 45.4 years (SD: 15.1). Among the QIs, use of plati...


Journal of Clinical Oncology | 2016

Treatment of bone and soft-tissue sarcoma patients in Japan: The distribution of patients and medical specialties by cancer topography and treatment modality.

Makoto Endo; Momoko Iwamoto; Masato Sugawara; Yoshihiro Araki; Tomoaki Mori; Koki Shimizu; Nokitaka Setsu; Eisuke Kobayashi; Yoshikazu Tanzawa; Fumihiko Nakatani; Hirokazu Chuman; Takahiro Higashi; Akira Kawai

e22544Background: Sarcoma clinical guidelines often emphasize the evaluation of patients by an expert multidisciplinary team, and thus in many countries, care is centralized to treatment centers. However, there are no standard guidelines for referrals of sarcoma patients in Japan, and the overall picture of where and by whom they are treated has never been systematically investigated. Methods: We used hospital-based cancer registry and health claims data of sarcoma patients diagnosed in Japan in 2012 and 2013. We analyzed the distribution of patients across hospitals and the extent of centralization of care across treatment modality and cancer topography. Results: We identified 1032 bone and 7257 soft-tissue sarcoma (STS) patients who were newly diagnosed in 2012 and 2013. Bone sarcomas occurred in the limbs in 55% of the patients, with 73% treated by orthopedic surgeons. Care was weakly centralized to 9 high-volume hospitals ( > 10 new cases per year) and 120 hospitals with 1-9 new cases. Care was greatl...


Journal of Clinical Oncology | 2014

Monitoring treatment wait times for cancer patients in Japan.

Yukiko Watanabe; Momoko Iwamoto; Takahiro Higashi

289 Background: Treatment wait times for cancer patients is among the key performance indicators of cancer policy in Japan, but has never been measured across a large number of patients. We aimed to measure treatment wait times for cancer patients across a large number of hospitals in Japan using health claims data. METHODS We developed a database of claims data (Jan 2011 - Dec 2012) linked to 2011 hospital-based cancer registry data of breast, cervical, colorectal, liver, lung, prostate and stomach cancer patients from 126 designated cancer hospitals in Japan. Treatment wait time was defined as the number of days between the date of diagnosis (the date on which a pathological test or imaging exam that contributed the most to the diagnosis was performed) and initiation of treatment. Dates of diagnostic tests, therapeutic procedures, and chemotherapy (chemo) administration were obtained from health claims data. We calculated wait times by cancer type, treatment, and stage, and investigated if these factors were significantly associated with wait times even after adjusting for age using multiple linear regression. RESULTS Among 44,102 cancer patients who received cancer treatment, the median wait time was 31 days (IQR=18-50) for all patients, and 32, 42, 31, 22, 22, 55 and 31 days for breast, cervical, colon, liver, lung, prostate and stomach cancer patients, respectively. Wait times were longer for surgery (36 days) compared to radiation (22 days) and chemo (21 days), and shorter for later stage patients: 48, 36, 35, 23, and 14 days for stages 0, I, II, III, and IV, respectively. Cancer type, treatment type, and stages were all independently and significantly associated with treatment wait times even after adjusting for age (p<0.05). CONCLUSIONS This is the first study to investigate treatment wait times across a large number of cancer hospitals in Japan. Treatment wait times were particularly longer for cervical and prostate cancer patients. While the effect of prolonged treatment wait times on clinical outcomes is unknown, longer treatment wait time increases the psychosocial stresses of cancer patients. Continuous monitoring and feedback of study findings to hospitals are required for improvements in the future.


Journal of Clinical Oncology | 2014

Establishing a system to monitor and evaluate the quality of cancer care in Japan.

Momoko Iwamoto; Fumiaki Nakamura; Takahiro Higashi

287 Background: To ensure equitable access to high-quality cancer care, efforts to routinely measure key performance indicators of cancer policy began in Japan in 2014. Although assessing the quality of cancer care is a vital component of this initiative, a system for evaluating process of care across a large number of hospitals has not yet been established. We aimed to establish this system by creating a database of health claims data linked to hospital-based cancer registry (HBCR) and measuring quality indicators (QIs) for cancer care. METHODS We created a database of 28 months (Sept10-Dec12) of health claims data linked to HBCR for 100,825 breast, prostate, colorectal, stomach, lung, liver, and cervical cancer patients who were newly diagnosed in 2011 from 178 designated cancer care hospitals in Japan. Among 206 QIs that were previously developed by a panel of experts, we measured 13 that were measureable from claims data: 1) seven QIs on adherence to guidelines on adjuvant therapy, 2) four QIs on lab tests, procedures, and medication, and 3) two QIs on supportive care. RESULTS QIs investigating adherence to clinical guidelines on adjuvant therapy tended to be lower compared to QIs for supportive care. For example, 48.0% [46.4, 49.6] of stage III colorectal cancer patients (n=3,638) received adjuvant chemotherapy (5FU+LV, UFT+LV, Cape, FOLFOX, or CapeOX) within 8 postoperative weeks, whereas 68.1% [67.2, 69.0] of patients (n=10,104) received three-drug combination (5HT3-r antagonist, dexamethasone, and aprepitant) before receiving highly emetogenic chemotherapy. QIs on appropriate testing and procedures were higher overall, such that 83.3% [82.6, 84.0] of invasive breast cancer patients (n=12,447) received HER2 testing. In all QIs, there was large variability in performance across hospitals. Feedback was given to hospitals through interactive webpages. CONCLUSIONS This is the first attempt at measuring the quality of cancer care across such a large number of hospitals in Japan. Our research showed that in all QIs, there was ample room for improvement. Continuous monitoring, improving feedback methods, expansion of QIs, and application of electronic health records, will be our next challenge as we move forward in this initiative.


Journal of Clinical Oncology | 2014

Assessing the validity of using claims data compared to medical chart reviews for measuring care quality in Japan.

Nana Nakamoto; Fumiaki Nakamura; Takahiro Higashi; Momoko Iwamoto; Asuka Amano; Masako Hirayasu; Hatsue Higa; Kuniko Asato; Kazuo Aoki; Masato Masuda

264 Background: Health insurance claims data have been used extensively as a less labor-intensive method of collecting data than medical record reviews, which are the preferred source of data collection in most medical studies. Although recent reports have raised questions about its validity of use in measuring care quality, validity of using claims data may differ by health systems and should therefore be assessed by country. We aimed to test the validity of using claims data in Japan by comparing quality performance scores obtained from claims data to those derived from medical record reviews. METHODS We reviewed medical records from Apr 2013 to Apr 2014 of gastric and colorectal cancer patients who were diagnosed in 2011 from 4 cancer care hospitals in Okinawa. We calculated the proportion of patients who received adjuvant chemotherapy for gastric and colorectal cancer using claims data, and compared the results with those obtained from medical record reviews. Chart reviews were performed by certified tumor registrars. We used kappa coefficients to measure the level of agreement between claims data and medical record reviews. RESULTS Analysis using claims data resulted in 14 Stage II and III gastric cancer patients who had undergone surgery, with 50% receiving adjuvant chemotherapy; whereas medical record reviews resulted in 19 patients, 94.7% of whom either received or had a clinically valid rationale for not undergoing adjuvant therapy. For colorectal patients, claims data resulted in 48.5% of 68 surgical stage III colorectal patients receiving adjuvant therapy, compared to 74.4% of 78 patients using medical record reviews who either received adjuvant therapy or had a valid reason for not undergoing therapy. Agreement between claims data and chart reviews was low (kappa=0.14) for gastric cancer, but fair (kappa =0.37) for colorectal cancer. CONCLUSIONS Our analysis showed that use of claims data may greatly underestimate quality performance measures if they are not compensated by medical record reviews. Claims data alone cannot capture a large proportion of patients who either choose not to, or has a clinically valid reason for not undergoing standard care.

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