Explore science by method, field &amp; evidence.

ACT

The ACT is a simple, rapid, patient-centered measure of asthma control. Developed by Robert Nathan and colleagues in 2004, this 5-item questionnaire quantifies how asthma symptoms, activity limitation, and nighttime awakening affect daily life. It is the most widely used asthma control measure in clinical practice and

3 sources2004

Adaptive case series

An adaptive case series is an observational study design that documents a consecutive group of patients with a shared condition or exposure while incorporating pre-specified rules for modifying data collection, monitoring, or stopping criteria as accumulating evidence warrants. It combines the descriptive richness of t

2 sources

Adaptive Case-Control Study

An adaptive case-control study is a case-control design that incorporates pre-specified rules allowing modification of study parameters — such as sample size, case-to-control ratio, or matching criteria — based on interim data, without compromising validity. It combines the efficiency of adaptive methodology with the r

2 sources1950

Adaptive Cohort Study

An adaptive cohort study is a longitudinal observational design that follows a defined group of individuals over time to assess exposure-outcome relationships, while incorporating pre-specified adaptation rules that allow protocol modifications — such as sample-size re-estimation, subgroup enrichment, or measurement sc

Adaptive Cross-Sectional Epidemiological Study

An adaptive cross-sectional epidemiological study combines the core logic of a cross-sectional survey — measuring exposures and outcomes simultaneously in a defined population at one point in time — with pre-specified adaptive rules that allow modifications to sampling strategy, sample size, or subgroup allocation base

Adaptive Diagnostic Accuracy Study

An adaptive diagnostic accuracy study evaluates how well an index test distinguishes between patients with and without a target condition, while incorporating pre-specified interim analyses that allow modifications — such as sample size re-estimation, threshold adjustment, or subgroup enrichment — based on accumulating

Adaptive Dose-Response Analysis

Adaptive dose-response analysis combines pre-specified dose-response modeling with planned interim looks that allow modifications — such as dropping ineffective doses or reallocating sample size — while maintaining statistical integrity. The most widely cited framework is MCP-Mod (Multiple Comparisons and Modeling), en

Adaptive Ecological Study

An adaptive ecological study is an observational epidemiological design in which the unit of analysis is a group or population (e.g., a region, country, or community) rather than an individual. It extends the classical ecological study by incorporating pre-specified interim decision rules that allow modifications — suc

Adaptive nested case-control

An adaptive nested case-control study embeds a case-control comparison within a defined cohort and incorporates pre-specified interim decision rules that allow modifications — such as control-to-case ratio adjustment or biomarker sub-sampling revision — based on accumulating data, without compromising the study's valid

2 sources1977

Adaptive Phase I Clinical Trial

An adaptive Phase I clinical trial is a first-in-human or early-phase dose-finding study that continuously updates the recommended dose after each patient cohort using a prespecified statistical model, rather than following a fixed rule. The goal is to identify the maximum tolerated dose (MTD) or the recommended Phase

Adaptive Phase II Clinical Trial

An adaptive Phase II clinical trial is a prospective experimental design in which pre-specified rules allow the study protocol to be modified — such as dropping arms, adjusting sample size, or narrowing the patient population — based on accumulating interim data, without inflating the Type I error rate. The design is w

2 sources1994

Adaptive Phase III clinical trial

An adaptive Phase III clinical trial is a confirmatory randomized controlled trial that incorporates pre-specified rules allowing modifications to the trial design — such as sample size re-estimation, dose selection, or population enrichment — based on accumulating interim data, while preserving the Type I error rate.

2 sources1969

Adaptive Phase IV study

An Adaptive Phase IV study is a post-marketing surveillance study conducted after a drug or intervention has received regulatory approval, augmented with pre-specified adaptive design elements that allow pre-planned modifications to the study protocol in response to accumulating data. These modifications may include sa

Adaptive Randomized Clinical Trial

An adaptive randomized clinical trial (adaptive RCT) is a prospective experimental study that uses pre-specified rules to modify one or more trial aspects — such as sample size, allocation ratios, or treatment arms — based on accumulating data collected during the trial itself, while maintaining statistical validity an

Adaptive screening test evaluation

Adaptive screening test evaluation is a psychometric and epidemiological framework for designing and assessing screening instruments whose item selection or stopping rules adjust dynamically to each respondent's response pattern. Rooted in item response theory (IRT) and computerized adaptive testing (CAT), the method u

2 sources1980

Adaptive Survival Analysis

Adaptive survival analysis integrates adaptive clinical trial design with time-to-event statistical methods, allowing pre-specified modifications to sample size, event targets, or allocation ratios at interim stages based on accumulating survival data. It is widely used in oncology, cardiovascular, and infectious disea

Adoption Scale

Innovation Adoption refers to the extent to which an innovation, evidence-based practice, or new technology is actually used by the target population or in the target setting. Adoption is typically measured as the percentage of eligible users/staff who have adopted the innovation by a specific time point, or the trajec

2 sources1983

Balanced Scorecard in Healthcare

The Balanced Scorecard is a strategic performance management framework that translates an organization's mission and strategy into a comprehensive set of performance measures across four perspectives: financial, customer, internal processes, and learning and growth. Developed by Kaplan and Norton in 1992 for general bu

3 sources1992

Barriers to Physical Activity Questionnaire

The Barriers to Physical Activity Questionnaire (BPA) is a scale designed to identify and measure perceived obstacles to exercise engagement. Rooted in the Health Belief Model and Health Promotion Model, the BPA assesses multiple categories of barriers—time constraints, lack of motivation, physical discomfort, cost, la

1 source1987

Basic Psychological Needs Scale

The Basic Psychological Needs Questionnaire (BPNQ), developed by Gagné (2003) and grounded in Self-Determination Theory by Deci and Ryan, measures satisfaction of three fundamental human psychological needs: Autonomy, Competence, and Relatedness. According to Self-Determination Theory, these three needs are universally

2 sources2003

Behavioral Regulation in Exercise Questionnaire

The Behavioral Regulation in Exercise Questionnaire—3 (BREQ-3) is a 24-item measure developed by Wilson and colleagues (2012) to assess the type and quality of motivation underlying exercise behavior. Grounded in Self-Determination Theory, the BREQ-3 measures six regulation types positioned on a continuum from amotivat

2 sources2012

Behaviour Change Wheel

The Behaviour Change Wheel (BCW) is a systematic, evidence-based framework for designing behavior change interventions. Developed by Michie et al. (2011) and built on the COM-B model (Capability, Opportunity, Motivation→Behavior), the BCW guides practitioners through a structured process: diagnose behavior change barri

3 sources2011

Budget Impact Analysis

Budget impact analysis estimates the financial consequences (net costs or savings) of implementing a new health technology in a specific healthcare system or population over a short time horizon (typically 1–5 years). Distinct from cost-effectiveness analysis (which compares health outcomes per dollar), BIA answers a b

3 sources2005

CAHPS Survey

The Consumer Assessment of Healthcare Providers and Systems (CAHPS) is a family of evidence-based surveys developed by the Agency for Healthcare Research and Quality (AHRQ) beginning in 1995. It systematically measures patient experiences across diverse healthcare settings including hospitals, ambulatory clinics, and h

3 sources1995

Case series

A case series is a descriptive observational study that documents the characteristics, clinical course, and outcomes of a group of patients who share a common condition, exposure, or intervention. Unlike case reports, which focus on a single patient, a case series aggregates data across multiple patients (typically thr

2 sources

Case-control study

A case-control study is a retrospective observational design in which individuals who have developed a disease or outcome of interest (cases) are compared with individuals who have not (controls) to determine whether prior exposure to a putative risk factor differs between the two groups. The primary measure of associa

2 sources1950

Case-crossover design

The case-crossover design is an observational epidemiological method that estimates whether a transient exposure triggers an acute event by comparing each case's exposure during a brief hazard window immediately before the event to their own exposure during earlier control periods. Because each person serves as their o

2 sources1991

public health nutrition

CDQ

The Children's Dietary Questionnaire (CDQ) is a parent-proxy or child self-report food frequency questionnaire designed to assess usual dietary intake in children and adolescents aged 6–18 years. Developed by Rockett and colleagues at Harvard School of Public Health in the 1990s, it captures consumption of 60–120 commo

2 sources1995

CHQ

The CHQ is a disease-specific quality of life measure for chronic heart failure (CHF). Developed by Luc Guyonnet and colleagues in 2000, this 20-item questionnaire assesses how heart failure affects dyspnea, fatigue, emotional function, and activity limitation. It is used in heart failure clinical trials and research t

3 sources2000

health education

CLES+T

The CLES+T is a 34-item self-report questionnaire measuring nursing students' perceptions of their clinical learning environment and the quality of supervision received from their clinical preceptor or teacher. Originally developed by Saarikoski and colleagues in 2007 and expanded in 2008 to include a specific teacher

2 sources2007

Clinical Audit

Clinical audit is a systematic, cyclical process that measures the quality of clinical care against evidence-based standards and benchmarks, identifies gaps, and implements improvements to bring practice into alignment with current best evidence. Originating in the UK NHS, clinical audit is now a fundamental quality as

3 sources1989

Clinical Handover Quality Scale

The Clinical Handover Quality Scale (CHQS) is a comprehensive framework and measurement tool for assessing the quality of clinical handovers—the critical communication process by which responsibility for a patient's care is transferred from one provider or team to another. Handovers occur multiple times daily in health

3 sources2008

Cohort Study

A cohort study assembles a group of individuals who share a common starting point — typically freedom from the outcome of interest — and follows them over time to observe who develops the outcome. By comparing incidence rates between exposed and unexposed subgroups, researchers can estimate relative risk and absolute r

2 sources1950

Consolidated Framework for Implementation Research

The Consolidated Framework for Implementation Research (CFIR) is a five-domain model designed to systematically evaluate the factors influencing implementation success of evidence-based interventions in health systems. Developed by Damschroder et al. (2009) and refined through extensive use across health domains, CFIR

3 sources2009

Cost-Benefit Analysis

Cost-benefit analysis compares the total monetary value of benefits produced by a program against its total monetary costs, reporting net present value (NPV) or benefit-cost ratio (BCR). Rooted in welfare economics and used extensively in public policy (transportation, environmental, education, health), CBA answers the

3 sources1970

Cost-Effectiveness Analysis

Cost-effectiveness analysis compares the incremental cost per unit of health benefit gained by one intervention relative to a comparator (standard care or best alternative). Developed rigorously in the 1980s by Drummond, Stoddart, and colleagues, CEA is now the standard framework for technology appraisal globally. NICE

3 sources1984

Cost-Effectiveness Analysis in HTA

Cost-Effectiveness Analysis (CEA) is an economic evaluation method that compares the cost and health benefits of alternative treatments to determine whether an intervention provides good value for money. Within Health Technology Assessment, CEA is the primary tool for recommending reimbursement and coverage decisions.

3 sources1996

public health

COVID-19 Anxiety Scale

The COVID-19 Anxiety Scale (CAS) is a brief, self-administered instrument designed to assess anxiety symptoms specifically related to the COVID-19 pandemic. Developed by Lipp and colleagues in 2020, it captures worry about infection, social isolation, and pandemic-related uncertainties. The scale is widely used in epid

1 source2020

public health

COVID-19 Mental Health Impact Scale

The COVID-19 Mental Health Impact Scale (CMHIS) is a brief, multidimensional instrument assessing anxiety, depression, and stress symptoms triggered by the COVID-19 pandemic. Developed by Wang and colleagues in 2020 during the initial pandemic wave in China, it captures the spectrum of psychological distress across mul

1 source2020

Cross-sectional epidemiological study

A cross-sectional epidemiological study measures the exposure(s) and outcome(s) of interest simultaneously in a defined population at a single point in time (or over a short period). Because there is no follow-up, it is the most efficient observational design for estimating disease prevalence and for generating hypothe

2 sources1960

clinical research

Cross-Sectional Study Design

A cross-sectional study (or prevalence study) measures exposure and outcome simultaneously at a single point in time, producing a 'snapshot' of a population. Respondents are recruited and surveyed (or examined) on the same occasion, capturing current prevalence of both exposure and disease. Cross-sectional studies are

3 sources1950

health education

CTQS

The CTQS is a self-report questionnaire measuring students' perceptions of their clinical educator's (preceptor, clinical instructor, or mentor) teaching quality and effectiveness. Developed by Ohrling, Hallberg, and Gaberson in the early 2000s, the CTQS evaluates dimensions of clinical teaching including role modeling

2 sources2001

health informatics

Cyberbullying Victimization Scale

The Cyberbullying Victimization Scale measures the frequency and nature of bullying experienced through digital channels—social media, text messages, gaming platforms, email, and online forums. Developed by Smith and colleagues (2008) and refined through meta-analytic synthesis by Kowalski and colleagues (2014), the sc

2 sources2008

health education

DASH

The DASH is a 20-item observer-rated instrument measuring the quality of debriefing—the structured, facilitated reflection following a healthcare simulation activity. Developed by Rudolph, Simon, and Raemer in 2006 at Massachusetts General Hospital, the DASH evaluates the debriefing facilitator's ability to create a ps

2 sources2006

Decision Analytic Modeling

Decision analytic modeling is a systematic framework for comparing health interventions by integrating evidence on probabilities, outcomes, costs, and patient preferences into a quantitative model. Developed by Pauker and Kassirer in 1975, decision analysis structures clinical uncertainty and economic trade-offs, enabl

3 sources1975

health informatics

Digital Health Acceptance Scale

The Digital Health Acceptance Scale measures the extent to which patients and providers perceive digital health technologies as useful, easy to use, and worth adopting. Grounded in Davis's Technology Acceptance Model (TAM) and extended by Venkatesh and colleagues through the Unified Theory of Acceptance and Use of Tech

2 sources1989

Disability-Adjusted Life Year

A DALY quantifies disease burden as the sum of years of life lost to premature death and years lived with disability. Developed by the World Health Organization and World Bank in 1990 as part of the Global Burden of Disease (GBD) study, DALYs enable epidemiologists and public health planners to compare disease burden a

3 sources1990

DLQI

The DLQI is the primary patient-centered outcome measure in dermatology research and clinical practice. Developed by Andrew Finlay and Gul Khan in 1994, this 10-item self-report questionnaire quantifies the impact of skin disease on patients' daily functioning, emotional well-being, social relationships, and work capac

3 sources1994

Dose-Response Analysis

Dose-response analysis quantifies the relationship between the magnitude of an exposure (the dose) and the probability or rate of an outcome (the response). It is a core analytical strategy in epidemiology and toxicology, providing evidence that increasing exposure systematically increases — or decreases — the risk of

2 sources

DQOL

The DQOL is a patient-reported measure of quality of life impact in people with diabetes. Developed by the Diabetes Control and Complications Trial (DCCT) Research Group in 1988, this 46-item questionnaire assesses how diabetes affects daily functioning, emotional well-being, worry about complications, and satisfaction

3 sources1988

Drug Abuse Screening Test

The Drug Abuse Screening Test (DAST) is a brief, validated self-report instrument developed by Skinner in 1982 to screen for drug abuse and dependence in medical and psychiatric populations. The 10-item DAST-10 comprises yes/no questions assessing drug use patterns, consequences, and interference with life functioning.

3 sources1982

EBPAS-36

The EBPAS-36 is a 36-item self-report questionnaire that assesses clinicians' and organizational leaders' attitudes toward adopting and implementing evidence-based practices (EBP). Developed by Aarons in 2005 and refined through multiple validation studies, it measures four core dimensions: perceived requirements to ad

1 source2005

health informatics

eHealth Literacy Scale

The eHealth Literacy Scale measures individuals' ability to seek, find, understand, and appraise health information from electronic sources and apply that knowledge to health decision-making. Developed by Norman and Skinner in 2006, it assesses functional, communicative, and critical digital health literacy competencie

1 source2006

Endemic Compartmental Models

Endemic compartmental models extend the classical SIR framework to capture diseases that persist indefinitely in a population rather than burning out after a single epidemic wave. The SIS model allows recovered individuals to return to susceptibility immediately; SIRS introduces temporary immunity before loss; SIRV add

1 source2000

EORTC QLQ-C30

The EORTC QLQ-C30 is the most widely used international instrument for assessing quality of life in cancer patients. Developed by the European Organisation for Research and Treatment of Cancer in 1993, it measures physical, emotional, cognitive, and social functioning alongside cancer-specific symptoms and financial im

3 sources1993

Epworth Sleepiness Scale

The Epworth Sleepiness Scale (ESS) is a brief, validated self-report instrument developed by Johns in 1991 to quantify the level of daytime somnolence or excessive daytime sleepiness. The ESS comprises eight items asking patients to rate the likelihood of dozing off in various everyday situations. It is the most common

3 sources1991

Exercise Self-Efficacy Scale

The Exercise Self-Efficacy Scale measures an individual's confidence in their ability to exercise regularly and maintain physical activity despite challenges. Grounded in Albert Bandura's Social Cognitive Theory, self-efficacy is the belief that one has the capability to execute a specific behavior and achieve desired

2 sources1997

Fagerström Test for Nicotine Dependence

The Fagerström Test for Nicotine Dependence (FTND) is a brief, validated self-report instrument originally developed by Fagerstrom in 1978 and revised by Heatherton and colleagues in 1991 to quantify the severity of nicotine dependence in cigarette smokers. The FTND comprises six items assessing morning cigarette use,

3 sources1991

public health

Fear of COVID-19 Scale

The Fear of COVID-19 Scale (FCV-19S) is a 7-item, self-report instrument assessing fear of COVID-19 infection across cognitive, emotional, and physiological domains. Developed by Ahorsu and colleagues in 2020, it measures threat perception, anxiety symptoms triggered by disease-related triggers, and avoidance behaviors

1 source2020