Surveillance design and evaluation
Indicator-based reporting, sentinel sites and event-based signals are combined, and each stream is evaluated for sensitivity, timeliness, completeness and representativeness against agreed surveillance attributes.
The Global Centre for Risk and Innovation (GCRI)
Epidemiology is the core science of this platform: it describes who becomes ill, where and when, identifies the determinants of disease, and evaluates what prevents it. Surveillance, outbreak investigation and burden estimation turn scattered reports into evidence that public health authorities can act on, with delays and biases stated.
GCRI · Established · service level R0
Epidemiology is the study of how disease is distributed in populations and what determines it, applied to prevent and control health problems. For health security it designs and evaluates surveillance, corrects for reporting delays and estimates the indirect effects of service disruption, with delays and biases stated.
The working screen behind this method: its structure, terms and states. Names are placeholders and values illustrative.
Health · Epidemiology for health security · Run R-8417
| Rt | 1.3 | 0.84 | 1.6 |
| Doubling time (days) | 18 | 4 | 29 |
| Reporting fraction | 0.4 | 0.2 | 0.9 |
Epidemiology studies the distribution and determinants of health and disease in populations. It provides the evidence used to detect outbreaks, estimate burden and evaluate interventions. In health and biosecurity, epidemiological evidence informs preparedness, resource allocation and the economic consequences of disease. It shows how health shocks interact with travel, labour, supply chains and public finance. The canonical description is on the STEM Commons.
Indicator-based reporting, sentinel sites and event-based signals are combined, and each stream is evaluated for sensitivity, timeliness, completeness and representativeness against agreed surveillance attributes.
Delay distributions estimated from past reports adjust recent counts for cases not yet reported, so the latest weeks are shown with their uncertainty rather than as an artificial decline.
Expected service use and outcomes are modelled from trends before a shock and compared with observed data, separating the indirect harm of interrupted care from the direct effects of the shock.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Public health surveillance | The continuous, systematic collection, analysis and interpretation of health data to plan and evaluate public health action. |
| Reporting delay | The time between disease onset or diagnosis and its appearance in surveillance data. |
| Sentinel surveillance | Surveillance through selected sites that report in detail, used to track trends rather than count every case. |
How far each division sits from a large city, with the roads and airports that carry patients and supplies, shown for Pacific Island states as an example geography for this subject.
Data from the source register feeds the methods; calibration and an independent test gate the estimate and its limits; the decision stays with the competent authority.
Fig. 01Nodes carry their type, metrics and state; connectors show what feeds what; the gates are the validation steps; the timeline is one application. Design of the method's use, not a record of a run.
Datasets and records used by epidemiology and public health science on this platform, with the role each plays and the label its values carry. Sources are listed in the source register.
| Data | Role | Label |
|---|---|---|
| Notifiable disease reporting systems | Case counts by place, time and person | REPORTED |
| Sentinel influenza and respiratory surveillance | Trends under stable case definitions | OBSERVED |
| Vital registration | Mortality baselines and excess deaths | OFFICIAL |
| Household and health surveys | Prevalence and coverage with sampling weights | ESTIMATED |
| Routine health information systems | Service volumes and facility reporting | REPORTED |
Findings are checked through replication, sensitivity analyses and comparison of independent surveillance streams. Transmission models are assessed by out-of-sample forecasting of case counts.
| Check | How it is done |
|---|---|
| Surveillance attribute review | Sensitivity, timeliness, completeness and representativeness are assessed against established surveillance evaluation guidelines |
| Independent stream comparison | Trends in notifications are compared with laboratory, sentinel and mortality data before a change is described |
| Case definition stability | Changes in definitions, testing or reporting are logged and their effect on trends assessed |
| Out-of-sample scoring | Transmission models are scored on periods they were not fitted to |
Reporting delays, under-ascertainment and confounding bias estimates. Behaviour change during outbreaks alters the parameters models rely on.
Health Nexus stewards epidemiology and public health science for the Consortium and reviews how it is applied across platforms.
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.