Wilson and Jungner Criteria for Screening

The Wilson-Jungner criteria represent the gold standard framework formulated by the WHO in 1968 to evaluate the suitability of a screening program for a specific disease.

The Ten Criteria

1. The condition sought should be an important health problem: Defined by high prevalence, high mortality, or significant morbidity (e.g., Congenital Hypothyroidism).
2. There should be an accepted treatment for patients with recognized disease: Screening is unethical if no intervention exists to improve the outcome.
3. Facilities for diagnosis and treatment should be available: The healthcare infrastructure must be able to handle the influx of screen-positive cases for definitive testing (e.g., confirmatory TSH/T4) and long-term management.
4. There should be a recognizable latent or early symptomatic stage: There must be a "window of opportunity" where the disease is detectable but hasn't caused irreversible damage.
5. There should be a suitable test or examination: The screening tool must be simple, safe, and validated.
6. The test should be acceptable to the population: Low-risk, non-invasive, and culturally appropriate (e.g., heel prick vs. venous draw in neonates).
7. The natural history of the condition, including development from latent to declared disease, should be adequately understood: Essential to distinguish between "pseudodisease" and clinically significant pathology.
8. There should be an agreed policy on whom to treat as patients: Clear diagnostic thresholds must be established to avoid over-treatment or under-treatment.
9. The cost of case-finding (including diagnosis and treatment) should be economically balanced in relation to possible expenditure on medical care as a whole: The program should be cost-effective compared to treating the complications of late-stage disease.
10. Case-finding should be a continuing process and not a "once and for all" project: Screening must be integrated into the healthcare system for sustained impact.

Evaluation of the Screening Test (Statistical Performance)

For a screening program to meet these criteria, the test must demonstrate:

• High Sensitivity: To minimize false negatives (not missing cases).
• High Specificity: To minimize false positives (avoiding unnecessary anxiety/costs).
• High Positive Predictive Value (PPV): Directly influenced by disease prevalence.

Modern Additions (Emerging Concepts)

• Genetic Privacy: Ensuring genomic data from screening (e.g., NGS) is protected.
• Equity: Universal access regardless of socio-economic status.
• Informed Choice: Parents must be educated on the implications of screening results.