Screening In Japan Research Articles

Defining sensitivity and specificity for quality control of organized cancer screening using Prefectural Cancer Registry data in Japan

Objective To decrease cancer mortality by implementing cancer screening programs, rigorous quality control measures that utilize standardized indicators are imperative. In Japan, although each municipality performing cancer screening programs implements quality control for their programs using the checklist authorized by the Ministry of Health, Labour and Welfare, compliance with all the items listed is not possible because calculating sensitivity and specificity using cancer registry data is difficult under these circumstances. This report elucidates the methodology for calculating indicators, including sensitivity and specificity, by delineating the parameters of false-negative cases within population-based cancer screening programs in Japan. Furthermore, the inherent challenges associated with ensuring the quality control of cancer screening procedures are expounded upon in this report.Method Data from the Prefectural Cancer Registry of Japan and cancer screening records compiled by municipalities were used to differentiate true-positive, true-negative, false-positive, and false-negative cases based on the combination of screening test outcomes and subsequent cancer incidence.Results A false-negative case was defined as an examinee who received a cancer diagnosis within one year after undergoing the screening test, notwithstanding the negative judgment of the cancer screening decision. The duration for judgment of true-positive, true-negative, and false-negative cases was also extended to one year. Cancer identification after cancer screening was ascertained using data from the Prefectural Cancer Registry, ensuring uniform categorization of the four cases. Subsequently, sensitivity and specificity values were calculated for municipalities conducting cancer screening programs.Conclusion Sensitivity and specificity are indispensable metrics for the inherent quality control of cancer screening because these parameters directly assess the efficacy of screening tests. The anticipated increase in the number of municipalities engaged in comprehensive quality control of cancer screening in Japan is poised to enhance the efficiency of cancer control policies. This augmentation will be accomplished through the meticulous utilization of the sensitivity and specificity values elucidated in the present report. The forthcoming challenges involve the proliferation of medical institutes reporting their adherence to the checklist stipulated by the National Cancer Center of Japan and the widespread dissemination of fundamental knowledge pertaining to cancer screening.

Sexual transmission of HTLV-1 resulting in uveitis with short-term latency and low proviral load.

Human T-cell Lymphotropic Virus Type 1 (HTLV-1) is traditionally linked to severe conditions such as adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy, and HTLV-1 uveitis, with vertical transmission, particularly mother to child thorough breastfeeding, considered the primary route. Despite efforts to reduce vertical transmission through antenatal screening in Japan, horizontal transmission has contributed to the rising prevalence of HTLV-1 in metropolitan areas. This case reports the youngest documented instance of HTLV-1 uveitis resulting from horizontal transmission through sexual contact in an 18-year-old woman. The patient presented with blurred vision in her right eye, and a comprehensive ophthalmologic examination identified vitreous opacity and retinal vasculitis. Serological tests confirmed HTLV-1 infection, with a proviral load of 2.66 copies per 100 peripheral blood mononuclear cells, measured by real-time PCR. A differential diagnosis confirmed HTLV-1 uveitis. Further family and partner investigations confirmed horizontal transmission, most likely through sexual contact. Over 6 years of follow-up, the patient experienced multiple recurrences of HTLV-1 uveitis and developed HTLV-1-associated keratopathy. This case highlights the potential for rapid disease progression with relatively low proviral loads and short latency, emphasizing the need for updated public health strategies for sexually active young populations.

Stomach Cancer Screening in Japan and Korea

Stomach Cancer Screening in Japan and Korea

School urinary screening program in Japan: history, outcomes, perspectives.

In Japan, pediatric urinary screening in schools for asymptomatic hematuria and proteinuria began in 1974 and has been very successful in detecting asymptomatic kidney diseases at an early stage. While the American Academy of Pediatrics recommended discontinuing urinalysis as a public health service in 2007, urinary screening in Japan has proven extremely successful in reducing the incidence of kidney failure with replacement therapy in children and young adults, especially through the early treatment of glomerulonephritis, such as immunoglobulin A nephropathy. Furthermore, the positivity rate on urinary screening in Japan is significantly lower than in the United States where the rate of false positive results is typically very high. Japan's seamless and efficient pediatric urinary screening may be a helpful example for other countries as well. However, the present investigation revealed several, unresolved problems with the system. For example, the methods used varied in terms of their cutoff point, additional examinations, and types of detailed testing. In Japan, various urinary screening methods are being tested to optimize the system for national use. Recently, the authors also recommended a system of detailed examinations, including beta-2 microglobulin testing and ultrasonography, to detect congenital anomalies of the kidney and urinary tract, the most common, underlying disease in kidney failure with replacement therapy, which is often overlooked until the symptoms have become grave. While school urinary screening has been ongoing for about 50 years and should be continued, improvements should also be made to it as needed.

Two-Year-Span Breast Cancer Screening Uptake in Japan after the COVID-19 Pandemic and Its Association with the COVID-19 Vaccination.

There is limited information on whether the COVID-19 pandemic was associated with decreased breast cancer screening uptake and if COVID-19 vaccination was associated with an increase in screening uptake. Our study explored the uptake of breast cancer screening in Japan after the COVID-19 pandemic and assessed its association with the COVID-19 vaccination. We analyzed data from the Japan COVID-19 and Society Internet Survey (JACSIS), a web-based prospective cohort survey, and we included 6110 women without cancer history who were aged 40 to 74 years that participated in the 2012 and 2022 surveys. We examined the regular breast cancer screening uptake before and after the pandemic and employed a multivariable Poisson regression model to seek any association between COVID-19 vaccination and screening uptake. Of 6110, 38.2% regularly participated in screening before the pandemic and 46.9% did so after the pandemic. Individuals unvaccinated due to health reasons (incidence rate ratio (IRR) = 0.47, 95% CI: 0.29-0.77, p = 0.003) and for other reasons (IRR = 0.73, 95% CI: 0.62-0.86, p < 0.001) were less likely to undergo screening compared to fully vaccinated individuals. There was no long-term decrease in breast cancer screening uptake after the pandemic in Japan. Vaccination was linked to increased uptake, but there was no dose relationship.

Evaluation of the exit screening policy among travelers arriving from Asian and pacific nations

BackgroundThe Japanese government has instituted border control measures against COVID-19, including entry and exit screening of people arriving from overseas. We sought to evaluate the effectiveness of the exit screening policy in Japan in reducing the risk of importing COVID-19 cases among travelers from Asian and Pacific countries.MethodsThe study period was stratified based on the timing of exit screening: (i) the control period (the pre-exit screening period from 25 October 2020 to 16 January 2021), (ii) the time period with the Alpha variant from 17 January to 10 April 2021, and (iii) the time period with the Delta variant from 2 May to 2 October 2021. Incidence data in the countries of origin were used to adjust for the risk of infection among travelers. The positivity rate of entry screening in Japan was compared among the three different study periods, adjusting for the risk of infection in the country of origin.ResultsThe adjusted relative risk of positivity was greatly reduced and substantially below the value of 1 during the Alpha variant period compared with the control period. Although the relative risks increased when comparing the Delta variant period against control, the estimate remained below 1, except for among travelers from India and Myanmar. The relative risk reduction was greatest in high-income countries, with estimates of 100% and 96% risk reduction during the Alpha and Delta variant periods, respectively, followed by upper-middle-income countries with estimates of 90% and 76%, respectively.ConclusionsEven in the presence of the Alpha and Delta variants, exit screening clearly reduced the risk of infection among travelers arriving from Asian and Pacific nations. As the testing relies on the country of origin, the effectiveness varied greatly by the socioeconomic income status and epidemiological situation of those countries. Test standardization and quality assurance may be required in low- and middle-income countries.

Using the C14:1/Medium-Chain Acylcarnitine Ratio Instead of C14:1 to Reduce False-Positive Results for Very-Long-Chain Acyl-CoA Dehydrogenase Deficiency in Newborn Screening in Japan.

Very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency is a long-chain fatty acid oxidation disorder that manifests as either a severe phenotype associated with cardiomyopathy, a hypoglycemic phenotype, or a myopathic phenotype. As the hypoglycemic phenotype can cause sudden infant death, VLCAD deficiency is included in newborn screening (NBS) panels in many countries. The tetradecenoylcarnitine (C14:1) level in dried blood specimens is commonly used as a primary marker for VLCAD deficiency in NBS panels. Its ratio to acetylcarnitine (C2) and various other acylcarnitines is used as secondary markers. In Japan, tandem mass spectrometry-based NBS, initially launched as a pilot study in 1997, was introduced to the nationwide NBS program in 2013. In the present study, we evaluated levels of acylcarnitine with various chain lengths (C18 to C2), free carnitine, and their ratios in 175 infants who tested positive for VLCAD deficiency with C14:1 and C14:1/C2 ratios. Our analyses indicated that the ratios of C14:1 to medium-chain acylcarnitines (C10, C8, and C6) were the most effective markers in reducing false-positive rates. Their use with appropriate cutoffs is expected to improve NBS performance for VLCAD deficiency.

Cost-Effectiveness of School Urinary Screening for Early Detection of IgA Nephropathy in Japan

The evidence for and against screening for chronic kidney disease in youths who are asymptomatic is inconsistent worldwide. Japan has been conducting urinary screening in students for 50 years, allowing for a full economic evaluation that includes the clinical benefits of early detection and intervention for chronic kidney disease. To evaluate the clinical effectiveness and cost-effectiveness of school urinary screening in Japan, with a focus on the benefits of the early detection and intervention for IgA nephropathy, and to explore key points in the model that are associated with the cost-effectiveness of the school urinary screening program. This economic evaluation with a cost-effectiveness analysis used a computer-simulated Markov model from the health care payer's perspective among a hypothetical cohort of 1 000 000 youths aged 6 years in first grade in Japanese elementary schools, followed up through junior and high school. The time horizon was lifetime. Costs and clinical outcomes were discounted at a rate of 2% per year. Costs were calculated in Japanese yen and 2020 US dollars (¥107 = US $1). School urinary screening for IgA nephropathy was compared with no screening. Outcomes were costs and quality-adjusted life-years (QALYs). Cost-effectiveness was determined by evaluating whether the incremental cost-effectiveness ratio (ICER) per QALY gained remained less than ¥7 500 000 (US $70 093). In the base case analysis, the ICER was ¥4 186 642 (US $39 127)/QALY, which was less than the threshold. There were 60.3 patients/1 000 000 patients in the no-screening strategy and 31.7 patients/1 000 000 patients in the screening strategy with an end-stage kidney disease. Cost-effectiveness improved as the number of screenings decreased (screening frequency <3 times: incremental cost, -¥75 [US $0.7]; incremental QALY, 0.00025; ICER, dominant), but the number of patients with end-stage kidney disease due to IgA nephropathy increased (40.9 patients/1 000 000 patients). Assuming the disutility due to false positives had a significant impact on the analysis; assuming a disutility of 0.01 or more, the population with no IgA nephropathy had an ICER greater than the threshold (¥8 304 093 [US $77 608]/QALY). This study found that Japanese school urinary screening was cost-effective, suggesting that it may be worthy of resource allocation. Key factors associated with cost-effectiveness were screening cost, the probability of incident detection outside of screening, and IgA nephropathy incidence, which may provide clues to decision-makers in other countries when evaluating the program in their own context.

Cancer screening in Japan 2 years after the COVID-19 pandemic: Changes in participation, 2017–2021

ObjectivesThe impact of the coronavirus disease (COVID-19) pandemic on cancer screening has become a global concern; compared with pre-pandemic levels, the number of individuals who underwent population-based cancer screening in Japan decreased by 10–30% in fiscal year (FY)2020. Therefore, it is important to monitor subsequent changes in the number of participants. MethodsThis descriptive study analysed data from a national database to determine changes from 2017 to 2021 in the number of people screened for gastric cancer (upper gastrointestinal [UGI] series or endoscopy), colorectal cancer (faecal immunochemical test), lung cancer (chest X-ray), breast cancer (mammography), and cervical cancer (Pap smear). ResultsCompared with the pre-pandemic period (FY 2017–2019), the number of participants in screening programmes in FY2021 decreased maximally for the gastric cancer UGI series (2.8 million to 2.2 million; −23.3 %), followed by those for lung cancer (7.9 million to 7.3 million; −8.2 %), colorectal cancer (8.4 million to 7.8 million; −7.3 %), breast cancer (3.1 million to 3.0 million; −4.5 %), and cervical cancer (4.3 million to 4.1 million; −3.2 %). Conversely, the number of people screened for endoscopic gastric cancer screening increased (1.0 million to 1.2 million; +13.1 %). ConclusionsThe number of participants, which decreased sharply immediately after the onset of the COVID-19 pandemic, recovered only slightly in FY2021 and did not return to pre-pandemic levels yet, except for endoscopic gastric cancer screening. Therefore, the impact of this decline in participation in cancer-detection programmes and changes in mortality should be monitored carefully.

How Can Artificial Intelligence Be Implemented Effectively in Diabetic Retinopathy Screening in Japan?

Diabetic retinopathy (DR) is a major microvascular complication of diabetes, affecting a substantial portion of diabetic patients worldwide. Timely intervention is pivotal in mitigating the risk of blindness associated with DR, yet early detection remains a challenge due to the absence of early symptoms. Screening programs have emerged as a strategy to address this burden, and this paper delves into the role of artificial intelligence (AI) in advancing DR screening in Japan. There are two pathways for DR screening in Japan: a health screening pathway and a clinical referral path from physicians to ophthalmologists. AI technologies that realize automated image classification by applying deep learning are emerging. These technologies have exhibited substantial promise, achieving sensitivity and specificity levels exceeding 90% in prospective studies. Moreover, we introduce the potential of Generative AI and large language models (LLMs) to transform healthcare delivery, particularly in patient engagement, medical records, and decision support. Considering the use of AI in DR screening in Japan, we propose to follow a seven-step framework for systematic screening and emphasize the importance of integrating AI into a well-designed screening program. Automated scoring systems with AI enhance screening quality, but their effectiveness depends on their integration into the broader screening ecosystem. LLMs emerge as an important tool to fill gaps in the screening process, from personalized invitations to reporting results, facilitating a seamless and efficient system. However, it is essential to address concerns surrounding technical accuracy and governance before full-scale integration into the healthcare system. In conclusion, this review highlights the challenges in the current screening pathway and the potential for AI, particularly LLM, to revolutionize DR screening in Japan. The future direction will depend on leadership from ophthalmologists and stakeholders to address long-standing challenges in DR screening so that all people have access to accessible and effective screening.

Cancer screening in Japan

Cancer screening in Japan

Longitudinal Analysis of Cost-effectiveness in Breast Cancer Screening in Japan

Longitudinal Analysis of Cost-effectiveness in Breast Cancer Screening in Japan

Rethinking screening mammography in Japan: next-generation breast cancer screening through breast awareness and supplemental ultrasonography.

Breast cancer mortality has not been reduced in Japan despite more than 20years of population-based screening mammography. Screening mammography might not be suitable for Japanese women who often have dense breasts, thus decreasing mammography sensitivity because of masking. The J-START study showed that breast ultrasonography increases the sensitivity and the detection rate for early invasive cancers and lowers the rate of interval cancers for Japanese women in their 40s. Breast awareness and breast cancer survival are directly correlated; however, breast awareness is not widely known in Japan. Next-generation breast cancer screening in Japan should consist of breast awareness campaigns for improving breast cancer literacy and supplemental breast ultrasonography to address the problem of false-negative mammograms attributable to dense breasts.

Marked reduction in the incidence of transfusion-transmitted hepatitis B virus infection after the introduction of antibody to hepatitis B core antigen and individual donation nucleic acid amplification screening in Japan.

In Japan, 41 million blood donations have been screened for hepatitis B virus (HBV) during the past 8.4 years using individual donation nucleic acid amplification testing (ID-NAT) and antibody to hepatitis B core antigen (anti-HBc) screening. Transfusion-transmitted HBV infection (TT-HBV) incidence was examined. Donated blood implicated in TT-HBV was analyzed for infection stage and DNA levels. Causative HBV strains were phylogenetically analyzed. Among 5162 (0.013%) ID-NAT positives, window period (WP) and occult HBV infection (OBI) accounted for 3.4% (176) and 11.5% (594), respectively. No OBI-related TT-HBV occurred. Seven blood donations caused eight TT-HBV cases, six of which were in the pre-ID-NAT WP, leaving one with an unresolved infection stage. Seven cases were caused by platelet concentrate (180 mL plasma) and one case by fresh-frozen plasma (200 mL plasma), which contained estimated infectious doses varying between 2 and 2300 HBV virions. HBV subgenotypes in five cases were HBV/A2. Complete genome sequences of the transmitting A2 strains were nearly identical (99.6%-100%) and clustered in a group that included HBV/HIV-1 coinfections and a higher proportion of donors in the acute infection phase (69%) than the other group of HBV/A2 sequences (5%). The incidence of observed TT-HBV cases has significantly reduced to 0.19 per million in the ID-NAT screening period. OBI-related TT-HBV was eliminated by anti-HBc screening. Established TT-HBV cases were caused by blood products with large plasma volumes containing extremely low HBV concentrations derived from blood donors at a very early infection stage.

Are HPV-negative lesions concerned for the introduction of primary HPV testing for cervical cancer screening in Japan?

In Japan, primary human papilloma virus (HPV) testing has not been introduced for cervical cancer screening due to concerns that HPV-negative lesions may be missed and a lack of Japanese data. The purpose of this study was to evaluate the validity of primary HPV testing in Japan by analyzing cervical intraepithelial neoplasia 2 (CIN2) or more/high-risk HPV- (CIN2+/hrHPV-) cases in cervical cancer screening. Data from 35 525 cervical cancer screenings with HPV testing and cervical cytology from 2011 to 2019 in Saga City, Japan, were reviewed. The cases with low-grade squamous intraepithelial lesion (LSIL+)/hrHPV- were analyzed in detail. The results of the 35 525 examinees were as follows: 31 123 were negative for intraepithelial lesion or malignancy (NILM)/hrHPV-, 2612 were NILM/hrHPV+, 262 were atypical squamous cells of undetermined significance (ASC-US)/hrHPV-, 213 were ASC-US/hrHPV+, 291 were LSIL+/hrHPV-, and 1024 were LSIL+/hrHPV+. Of the 256 LSIL+/hrHPV- examinees for whom histology was available, CIN2+ were CIN2 9.4% (24/256), CIN3 3.9% (10/256), cervical adenocarcinoma 0.4% (1/256), uterine corpus cancer 1.2% (3/256), and uterine sarcoma 0.4% (1/256). Overall, the rate of LSIL+/hrHPV- was 0.82% (291/35.525), 0.1% (36/35525) of which were cervical lesions with CIN2+. Only one cervical adenocarcinoma was detected, but gastric-type adenocarcinoma was not included. HPV-negative CIN2+ or cervical adenocarcinoma is not a concern for the introduction of primary HPV screening in Japan. Primary HPV testing in cervical cancer screening is considered a feasible method that can be used in Japan, although an algorithm suitable for Japan and a national-level management system need to be established.

Overcoming the limitations of screening mammography in Japan and Korea: a paradigm shift to personalized breast cancer screening based on ultrasonography.

Screening mammography programs have been implemented in numerous Western countries with the aim of reducing breast cancer mortality. However, despite over 20 years of population-based screening mammography, the mortality rates in Japan and Korea continue to rise. This may be due to the fact that screening mammography is not as effective for Japanese and Korean women, who often have dense breasts. This density decreases the sensitivity of mammography due to a masking effect. Therefore, the early detection of small invasive cancers requires more than just mammography, particularly for women in their 40s. This review discusses the limitations and challenges of screening mammography, as well as the keys to successful population-based breast cancer screening in Japan and Korea. This includes a focus on breast ultrasonography techniques, which are based on histopathologic anatomical knowledge, and personalized screening strategies that are based on risk assessments measured by glandular tissue components.

Development of a Model for Quantitative Assessment of Newborn Screening in Japan Using the Analytic Hierarchy Process.

Whether or not conditions should be included in publicly funded newborn screening (NBS) programs should be discussed according to objective and transparent criteria. Certain criteria have been developed for the introduction of NBS programs in the context of individual countries; however, there are no standard selection criteria for NBS programs in Japan. This study aimed to develop a quantitative scoring model to assess newborn screening that incorporates the views of a variety of stakeholders in Japan. The five recommended eligibility criteria for NBS were stratified based on previous studies and expert opinions, using the analytic hierarchy process. We conducted a cross-sectional, web-based questionnaire targeting a wide range of people involved in NBS to investigate pairwise comparisons of the evaluation items between February and April of 2022. There were 143 respondents. Most of our respondents (44.1%) were physicians. Fifty-eight respondents (40.6%) had been engaged in NBS-related research or work for more than 10 years. The distribution of allocation points was the highest for 'intervention', 'screening test', 'follow-up setting', 'economic evaluation', and 'disease/condition', in that order. The algorithm in this study will guide decision makers in collecting and evaluating objective data, thus enabling transparent discussions to occur.

Reproductive decision-making following the diagnosis of an inherited metabolic disorder via newborn screening in Japan: a qualitative study.

The aim of the study was to describe the factors influencing the reproductive decision-making of carrier parents after the diagnosis of an inherited metabolic disorder in newborn screening in Japan. We conducted a semi-structured interview with 12 parents and analyzed data based on content analysis methodology. We identified 11 factors, including personal evaluation of recurrence risk, understanding of hereditary phenomena, concerns and desires for future planned children, concerns for older siblings, perceptions of diseases, degree of acceptance and denial of diseases, the opinions of others on having another child, optimism/faith in positive outcomes, self-evaluation of parental capability, factors unrelated to the disease, and the "right" time to expand the family. Perceptions and acceptance of disease are both important factors in reproductive decision-making, though these factors fluctuate continuously during the childbearing period. Therefore, effective reproductive genetic counseling will be considerate of the parents' fluctuating perceptions on reproduction. To ensure that the decision-making process is for the benefit of the parents and future children, long-term involvement of health care professionals is needed to assess the client's acceptance of the disease and their understanding of genetic phenomena and recurrence rates.

Association between metabolic syndrome and participation in colorectal cancer screening in Japan: A retrospective cohort analysis using LIFE study data

BackgroundPeople with metabolic syndrome have an elevated risk of developing colorectal cancer (CRC), and are recommended to undergo cancer screening. This study examined the association between metabolic syndrome and CRC screening participation in Japan. MethodsThis retrospective cohort study was conducted using insurance claims data, health checkup data, and cancer screening data from a Japanese city. The study population comprised persons aged 40–74 years who had undergone health checkups between fiscal years (FY) 2016 and 2019. The exposure was metabolic syndrome risk (high risk, moderate risk, and no risk) as determined during health checkups. The outcome was CRC screening participation. Logistic regression analyses were performed to examine the associations between metabolic syndrome risk and CRC screening participation. ResultsWe analyzed 20,558 people in the FY2016 cohort, 19,065 people in the FY2017 cohort, 17,496 people in the FY2018 cohort, and 15,647 people in the FY2019 cohort. The odds of CRC screening participation were significantly lower in the moderate-risk group (P < 0.05) in all FYs except FY2019 and the high-risk group (P < 0.001) in all FYs when compared with the no-risk group. When analyzed according to age group, older persons aged 65–74 years generally had significantly lower odds of CRC screening participation than persons aged 40–49 years across all metabolic syndrome risk groups. ConclusionThis is the first study from Japan to show that people with metabolic syndrome, especially older persons aged 65–74 years, are less likely to undergo CRC screening than people without metabolic syndrome. These findings indicate a need to develop and implement age-specific measures to increase cancer screening uptake among persons with metabolic syndrome.

The current situation of screening mammography and toward riskstratified breast cancer screening in Japan

日本の乳がん検診は，欧米のデータで乳癌死亡率減少効果が唯一証明されている検診マンモグラフィを４０歳以上の女性に対して２年に１回施行するという画一的な方法を推奨している。既に検診マンモグラフィを施行して２０年以上経過しているが，今もなお日本人女性の乳癌死亡率が増加を続けている事実から現行のわが国の乳がん検診制度が最適とは言えない。検診マンモグラフィ一辺倒である現行の考え方からのパラダイムシフトが必要である。日本の次世代乳がん検診はブレスト・アウェアネスの啓発を行うとともに，組織型乳がん検診を土台とするリスク層別化乳がん検診を導入することで乳癌死亡率減少効果のある，受診率の高い，適切な乳がん検診に変貌することが可能かもしれない。さらにJ―START は，リスク層別化乳がん検診のランダム化比較試験であるという解釈が広く理解を得られるようになれば，４０～４９歳の日本人女性に対しての超音波検査併用検診マンモグラフィが感度向上，早期浸潤癌発見率向上，中間期癌減少を証明しているので，日本人女性の乳癌死亡率減少効果を期待できる新しい乳がん検診の有用な手段／方法としてその早期導入の方策を具体的に議論することが可能となる。