研究手法をまとめたひとつのカタログ — 各手法の仕組み、使いどころ、そしてできないことを学べます。
A pragmatic diagnostic accuracy study evaluates how well a diagnostic test performs under real-world clinical conditions — not in idealized, tightly controlled settings. Conducted within routine care workflows, it measures sensitivity, specificity, predictive values, and likelihood ratios for an index test against a re
Pragmatic dose-response analysis quantifies how varying levels of an exposure or treatment relate to clinical outcomes under real-world conditions. By embedding dose-response questions within pragmatic study designs — broad eligibility criteria, routine care settings, and heterogeneous populations — it bridges the gap
A pragmatic ecological study is an observational epidemiological design that examines associations between exposures and outcomes at the population or group level — using routinely collected, real-world data — with the explicit goal of informing practical public health decisions under everyday conditions. Rather than c
A pragmatic nested case-control study embeds a case-control analysis within a pre-existing real-world cohort — typically drawn from electronic health records, administrative claims, or disease registries — to examine associations between exposures and outcomes under routine clinical conditions. Controls are sampled fro
A pragmatic Phase II clinical trial is an early-to-mid-stage interventional study that evaluates a new treatment's preliminary efficacy and safety under conditions that approximate real-world clinical practice rather than tightly controlled experimental settings. It sits between pure explanatory Phase II trials and lar
A pragmatic phase III clinical trial is a large-scale randomized study designed to evaluate whether an intervention works under the conditions of everyday clinical practice rather than the tightly controlled environment of an explanatory efficacy trial. It recruits a broad, representative patient population, allows fle
A pragmatic Phase IV study is a post-marketing investigation conducted under routine clinical conditions to evaluate a drug or device's real-world effectiveness, long-term safety, and comparative performance. Unlike the controlled Phase III environment, it intentionally minimizes protocol restrictions — broad eligibili
A pragmatic randomized clinical trial (pragmatic RCT) is an interventional study that tests whether a treatment works under routine clinical conditions, as opposed to the tightly controlled setting of an explanatory trial. It prioritizes broad eligibility, flexible delivery, and patient-relevant outcomes to answer the
A pragmatic screening test evaluation assesses the real-world effectiveness of a screening instrument under routine clinical or public-health conditions — rather than the tightly controlled, ideal-participant settings of explanatory studies. It asks whether the screening tool performs adequately in the actual populatio
Pragmatic survival analysis applies time-to-event statistical methods within pragmatic or real-world settings, estimating how long patients survive, remain event-free, or retain treatment benefit under conditions of routine clinical practice. Unlike explanatory survival analyses conducted under tightly controlled trial
A prospective case series is an observational study design in which a group of patients with a particular condition, exposure, or intervention is identified in advance and followed forward in time according to a pre-specified protocol. Data on outcomes, adverse events, and clinical course are collected as they occur, y
A prospective case-control study embeds the case-control logic within a defined cohort followed forward in time. Cases are identified as they occur, rather than looked up in records after the fact, and controls are sampled from the same prospectively monitored base population. This forward-looking approach allows colle
The prospective case-crossover design is an observational epidemiological study in which each case serves as their own control. Unlike the retrospective variant, exposures are recorded in real time as participants are followed forward, eliminating recall bias. It is particularly suited to investigating transient enviro
A prospective cohort study assembles a group of participants who are free of the outcome of interest at baseline, measures their exposures, and then follows them forward in time to record who develops the outcome. By collecting exposure data before outcomes occur, it establishes a clear temporal sequence that supports
A prospective diagnostic accuracy study enrolls participants before any test results are known and follows them forward in time to evaluate how well an index test (the test under evaluation) distinguishes individuals with and without a target condition, using a reference standard applied independently. Key accuracy met
Prospective dose-response analysis is an epidemiological approach that measures exposure levels in a defined population before outcomes occur, then quantifies how the risk or magnitude of an outcome changes systematically as exposure increases. By collecting exposure data prospectively, researchers can establish tempor
A prospective ecological study is an observational epidemiological design in which groups — not individuals — serve as the unit of analysis, and exposure data are collected going forward in time before outcomes are measured. Investigators define geographically, politically, or socially bounded populations, characterise
A prospective nested case-control study enrolls a cohort before disease onset, follows participants forward in time, and then — once cases develop — samples matched controls from those still at risk at the time each case occurs. By embedding the case-control comparison inside a prospective cohort, the design combines t
A prospective Phase IV study is a post-marketing investigation conducted after a drug, device, or intervention has received regulatory approval, following participants forward in real time to collect safety, effectiveness, and utilization data under routine clinical practice conditions. Unlike retrospective designs tha
A prospective randomized clinical trial (RCT) is an experimental study in which participants are assigned to intervention or control groups by chance before any outcomes are observed, then followed forward in time. Random allocation eliminates systematic selection bias, making this design the gold standard for establis
A prospective screening test evaluation enrolls participants before the outcome is known, applies the screening test and the reference standard in temporal sequence, and measures how accurately the test identifies individuals with or without the target condition. This forward-looking design minimizes workup bias and sp
Prospective survival analysis is a longitudinal study design in which participants are enrolled before the event of interest occurs, followed forward in time under standardised conditions, and analysed using survival-analytic methods to estimate the time until a defined clinical endpoint — such as death, disease recurr
The PSCS is a self-report instrument measuring healthcare students' and professionals' self-perceived competence in patient safety practices, safety awareness, and safety culture engagement. Developed by Lachman and informed by James Reason's theoretical framework of human error and systems thinking, the PSCS evaluates
A QALY measures health benefit as utility weight (0 = death, 1 = perfect health) multiplied by time lived. Developed by Alan Williams in 1985, QALYs enable comparison of disparate health interventions on a common metric. Used globally by health technology assessment bodies—NICE (UK), HAS (France), CADTH (Canada), WHO—t
The RA-QoL is a disease-specific quality of life measure for rheumatoid arthritis (RA). Developed by Stephen McKenna and colleagues in 1997, this 30-item questionnaire quantifies how RA affects daily activities, emotional well-being, functional independence, and social engagement. It is a standard outcome measure in RA
A randomized clinical trial (RCT) is an experimental study design in which participants are randomly assigned to an intervention group or a control group, then followed prospectively to compare outcomes. Random allocation is the defining feature: it distributes known and unknown confounders across groups by chance, mak
The RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, Maintenance) is a five-dimension evaluation tool designed to assess the public health impact of evidence-based interventions in real-world settings. Developed by Glasgow et al. (1999) to address the gap between efficacy trials (controlled conditions)
The basic reproduction number R0 is the expected number of secondary infections produced by a single infectious individual introduced into a fully susceptible population. Formally defined and computationally grounded by Diekmann, Heesterbeek, and Metz in 1990 using the next-generation matrix approach, R0 serves as the
A retrospective case series is an observational study that systematically describes the clinical features, treatments, and outcomes of a defined group of patients by examining pre-existing medical records or administrative data. It looks backward in time — data have already been recorded before the study begins. With n
A retrospective case-control study identifies individuals who already have an outcome of interest (cases) and a comparable group without it (controls), then looks backward in time using existing records to determine prior exposure to a suspected risk factor. The primary measure of association is the odds ratio. This de
A retrospective cohort study assembles a group of individuals who share a common starting point and reconstructs their exposure history and subsequent outcomes entirely from pre-existing records. Because the data have already been collected before the study begins, the design is far faster and cheaper than a prospectiv
A retrospective cross-sectional epidemiological study measures the prevalence of exposures and outcomes at a single analytical time point using data that were originally recorded in the past — such as medical records, administrative databases, or disease registries. It combines the snapshot logic of a cross-sectional d
A retrospective diagnostic accuracy study evaluates how well a diagnostic test (the index test) correctly identifies a target condition by applying it to previously collected data or archived specimens alongside a reference standard. Because both index test results and reference standard results are drawn from existing
A retrospective nested case-control study is an efficient observational design in which cases and matched controls are sampled from within an already-assembled retrospective cohort. Exposure data are retrieved from historical records only for selected participants, dramatically reducing data-collection costs while reta
A retrospective Phase II clinical trial evaluates a treatment's preliminary efficacy and safety signals using existing archival data — medical records, registries, or electronic health records — rather than prospectively enrolling new patients. It mirrors the objectives of a standard Phase II trial (estimating response
A retrospective Phase III clinical trial evaluates the comparative efficacy and safety of an intervention against a control using data that were collected before the study was designed. Rather than enrolling new patients prospectively, researchers analyze existing records — from registries, hospital databases, or histo
Retrospective survival analysis applies time-to-event statistical methods — most commonly the Kaplan-Meier estimator and Cox proportional hazards regression — to data collected from past records rather than through prospective follow-up. The researcher looks back at medical records, disease registries, or administrativ
The RIPLS is a 19-item self-report questionnaire designed to measure healthcare students' attitudes and readiness toward interprofessional learning and collaboration. Developed by Parsell and Bligh in 1999, it assesses three core dimensions of interprofessional readiness: teamwork and collaboration, professional identi
A risk-adjusted case series is an observational study design that reports outcomes for a consecutive or defined group of patients undergoing the same procedure or sharing a condition, while statistically correcting for differences in patient-level baseline risk. Rather than presenting raw complication or mortality rate
A risk-adjusted case-control study is an observational design that identifies individuals with a disease outcome (cases) and comparable individuals without it (controls), then uses statistical adjustment — most commonly multivariable logistic regression — to estimate the association between an exposure and the outcome
The risk-adjusted case-crossover design is a self-matched epidemiological method that compares a person's exposure during a brief hazard window immediately preceding an acute event to their exposure during one or more control windows from the same individual, while formally accounting for time-varying or time-fixed cov
A risk-adjusted cohort study is an observational epidemiological design in which a defined group of individuals is followed over time to compare outcomes between exposed and unexposed subgroups, with statistical methods applied to control for measured confounders. Adjustment strategies — including multivariable regress
A risk-adjusted cross-sectional epidemiological study measures the prevalence of health outcomes or exposures in a defined population at a single point in time, then applies statistical risk-adjustment methods — such as regression standardization, direct or indirect standardization, or propensity scoring — to remove th
A risk-adjusted diagnostic accuracy study evaluates how well an index test identifies a target condition while explicitly accounting for patient-level risk factors that influence either disease prevalence or test performance. By adjusting for case-mix, it yields accuracy estimates — sensitivity, specificity, and AUC —
Risk-adjusted dose-response analysis quantifies the relationship between increasing levels of an exposure (dose) and the probability or magnitude of an outcome (response), while simultaneously controlling for baseline risk factors that could confound or modify this relationship. The method is widely applied in clinical
A risk-adjusted ecological study is an observational epidemiological design that examines associations between exposures and outcomes measured at the group or area level — such as regions, hospitals, or countries — while statistically controlling for known risk factors also measured at that level. By incorporating risk
A risk-adjusted nested case-control study embeds a case-control comparison inside a defined cohort and explicitly accounts for differences in baseline risk between cases and controls through covariate adjustment — most commonly via risk scores, propensity scores, or stratification. It preserves the efficiency advantage
A risk-adjusted Phase I clinical trial is a first-in-human or dose-finding study that explicitly incorporates patient-level risk covariates — such as organ function, prior therapy, or genetic markers — into the dose-escalation model. Rather than treating all enrolled participants as homogeneous, the design accounts for
A risk-adjusted Phase II clinical trial is an early-phase efficacy design that incorporates patient baseline risk strata — such as disease severity, prognostic score, or comorbidity burden — directly into the trial's stopping rules and sample size calculations. By conditioning response targets and futility/efficacy thr
A risk-adjusted Phase III clinical trial is a large-scale confirmatory randomized experiment that explicitly incorporates participants' baseline prognostic risk profile into both the randomization process and the primary statistical analysis. By stratifying patients on known risk factors before allocation and adjusting
A risk-adjusted Phase IV study is an observational or semi-experimental post-marketing study conducted after a drug or device has received regulatory approval. It uses statistical risk-adjustment techniques — such as propensity score matching, inverse probability weighting, or multivariable regression — to control for
Risk-adjusted screening test evaluation assesses the sensitivity, specificity, and overall discriminatory accuracy of a screening test after accounting for patient-level risk factors (covariates) that independently influence test results or disease prevalence. By conditioning performance metrics on observed covariates
The RPQ is a self-report instrument measuring the degree to which healthcare students and professionals engage in reflective practice—the deliberate examination of their clinical experiences, decisions, and actions to extract learning and improve future practice. Developed by Sobral and refined by Saarikoski and collea
The Safety Attitudes Questionnaire (SAQ) is a 60-item self-report instrument developed by Sexton and colleagues in the early 2000s to measure organizational safety culture in healthcare settings. Adapted from crew resource management research in aviation, the SAQ assesses clinician and non-clinician perceptions of safe
Scaling Up is the deliberate expansion of successful health interventions from pilot sites to entire health systems, regions, or countries. Formalized by the World Health Organization (WHO) and Simmons et al. (2007), scaling up is distinct from simple dissemination; it requires systematic planning, financial modeling,
The SCPS is a self-report questionnaire measuring students' overall satisfaction with their clinical placement experience, including satisfaction with the learning environment, educator support, clinical opportunities, and facility resources. Originally developed by Papastavrou and colleagues in Cyprus (2007–2010), the
Screening test evaluation is a systematic epidemiological approach for assessing whether a test or program can accurately and cost-effectively identify individuals with a condition before symptoms appear. It quantifies diagnostic performance metrics — sensitivity, specificity, predictive values, and the ROC curve — and
The SEIR model is a deterministic compartmental model that partitions a closed population into four epidemiological states: Susceptible (S), Exposed (E), Infectious (I), and Recovered (R). It extends the classic SIR framework by explicitly incorporating a latent period during which individuals have been infected but ar
The SIR model is a foundational mathematical framework for describing the spread of infectious diseases through a population. Introduced by William Ogilvy Kermack and Anderson Gray McKendrick in 1927, it partitions a closed population of size N into three mutually exclusive compartments: Susceptible (S), Infectious (I)
The Stages of Concern Questionnaire (SoC) is a 35-item self-report instrument that measures the types and intensity of concerns individuals experience when adopting new practices, technologies, or innovations. Developed by Hall and colleagues in the 1970s as part of the Concerns-Based Adoption Model (CBAM), the SoC mea