Public health and healthcare

Consecutive case series

A consecutive case series is an observational clinical study design in which all eligible patients over a defined period are enrolled and their outcomes described, with no control group.

Consequences of the Black Death

Consequences of the Black Death: the 1347–1353 Yersinia pestis pandemic killed 30–60% of affected populations, then raised wages, helped end western European serfdom, drove the Little and Great Divergences, and reshaped religion, art, and the state.

CONSORT statement

The CONSORT statement (Consolidated Standards of Reporting Trials) is a reporting guideline for randomized controlled trial reports, endorsed by more than 400 journals since 1996; the current version is CONSORT 2025.

Consumer Product Safety

Consumer product safety: regulatory measures and standards ensuring non-food consumer goods are safe. Covers the U.S. CPSC (CPSA 1972, CPSIA 2008), EU GPSR, and 2025 UN principles.

Consumption of Tide Pods

Consumption of Tide Pods is the ingestion of liquid laundry detergent packets, mainly by young children and, during the 2018 Tide Pod challenge, by teenagers.

Contact tracing

Contact tracing is a public health method that identifies people exposed to an infectious disease case, then monitors, tests, or supports them to interrupt onward transmission.

Contract Services

Contract services, or contracting out, are services purchased from external providers under agreements specifying quantity, quality, price, and period; widely used in health care for support, clinical, and hospital management services, with mixed documented effects.

Controlled before-after study

A controlled before-after study is a quasi-experimental design measuring outcomes before and after an intervention in both intervention and comparison groups, without randomization, to estimate the intervention's effect.

Controlled interrupted time series analysis

Controlled interrupted time series (CITS) analysis is a quasi-experimental design that evaluates health or policy interventions by comparing before-and-after trends between an exposed population and an unexposed control.

Convalescent Hospitals

Convalescent hospitals are facilities providing care after an acute illness until health is restored; in the US the term now means skilled nursing facilities, historically Scottish homes and WWII Army hospitals, today compared with IRFs for rehabilitation.

COPD trial (NCT03773809)

NCT03773809, a completed blinded randomized trial at Bangabandhu Sheikh Mujib Medical University, Dhaka, tested 40,000 IU vitamin D3 versus placebo for heart rate variability in vitamin D-deficient asthma-COPD overlap patients, with published improvements in HRV.

COPDGene study

COPDGene (Genetic Epidemiology of COPD) study: NHLBI-funded US multicenter cohort of over 10,000 smokers (NCT00608764) begun 2007, using spirometry, genome-wide genotyping, and inspiratory/expiratory CT to find genetic factors and phenotypes of COPD.

CORC LTO study

CORC LTO study (NCT05394025), a VA Office of Research and Development observational study comparing long-term COVID-19 outcomes in infected versus matched uninfected Veterans using EHR, Medicare, survey, and interview data; started 2022, completed June 2024, 479 enrolled.

Corewell Health

Corewell Health is Michigan's not-for-profit health system formed February 1, 2022 from the Beaumont Health and Spectrum Health merger, renamed from BHSH in October 2022, with 21 hospitals, 60,000+ team members, and the Priority Health plan.

Oct 20, 2026

CoronavRheum trial

CoronavRheum (NCT04754698) is a phase 4 trial at University of São Paulo testing CoronaVac in autoimmune rheumatic disease patients and people with HIV; lower but acceptable immunogenicity, no severe adverse events.

Cost Control

Cost control (cost containment): the containment, regulation, or restraint of costs, chiefly in health care. Key policies include cost sharing, managed care, reference pricing, generic substitution, and budgeting.

Cost of Illness

Cost of illness (COI), also called burden of disease or economic burden of disease, is a health economics measure of the total monetary cost of a disease: direct medical and nonmedical costs, indirect productivity losses, and intangible costs, studied from defined perspectives.

Cost Savings

Cost savings: reductions in all or any portion of the costs of providing goods or services (MeSH D017046), accruing to provider or consumer; in healthcare, documented through bundled payment, ACO, and prevention programs.

Cost-consequence analysis

Cost-consequence analysis is a type of economic evaluation in healthcare that presents costs and outcomes of interventions in a disaggregated list rather than a single ratio.

Cost-Effectiveness Analysis

Cost-effectiveness analysis (CEA) is an economic evaluation method that compares an intervention's costs with its health outcomes, such as life years gained or QALYs, judging it against alternatives.

Cost-effectiveness model

A cost-effectiveness model is a decision-analytic model that compares the costs and health outcomes of alternative healthcare interventions, expressing results as an incremental cost-effectiveness ratio, often dollars per QALY gained.

Cost-utility analysis

Cost-utility analysis (CUA) is an economic evaluation comparing the costs of health interventions with outcomes in quality-adjusted life years, reported as cost per QALY and used for reimbursement decisions.

COSYCONET study

COSYCONET (COPD and SYstemic consequences-COmorbidities NETwork) is a German multicenter COPD cohort of 2741 patients recruited 2010–2013 at 31 centers, studying comorbidities, systemic inflammation, and mortality predictors.

Cotesting

Cotesting is a cervical cancer screening strategy combining HPV testing and the Pap test on the same specimen, recommended every 5 years for women aged 30 to 65.

County Hospitals

County hospitals are hospitals owned and operated by county governments, historically the US care providers of last resort for indigent patients; key facts cover governance, safety-net funding, quality, and closures.

COVID-19

COVID-19 (coronavirus disease 2019) is the respiratory disease caused by SARS-CoV-2, first detected in Wuhan in December 2019; WHO declared a pandemic in March 2020 and ended the PHEIC in May 2023, with about 776.8 million recorded cases and 7 million deaths.