KPS
A 10-instrument clinical test battery on one engine, with reliable-change tracking and health-data protection built in.
My role: Designed the measurement system end to end: instrument selection, scoring, norms, change metrics and the security model.
The Challenge
A forensic-psychiatry clinic needed to run a battery of standardized and custom psychological tests as routine work: administer each one, score it against published norms, and track real change over time. One app per test does not scale, and the data is the most sensitive kind there is: health data in a forensic setting, where every result has to be defensible.
The Approach
I built one test engine that reads each instrument from a definition file (items, scoring rules, norms and cutoffs), so adding a test means writing a definition. Unusual instruments get a custom scoring path. Repeat testing is reported with a Reliable Change Index, so clinicians see real change instead of measurement noise. Security and GDPR compliance were designed in from the first commit.
Results
- 10 instruments covering anxiety, depression, substance use, psychosis, suicide risk and aggression
- Scoring against published norms and clinical cutoffs
- Reliable-change tracking that separates real change from measurement error
- Health-data protection: field-level encryption, an append-only audit log, passwordless sign-in, need-to-know access
- Live at kps.badania.org, in testing with the clinic
The decision that mattered was building one engine instead of ten tools. A clinic’s battery keeps changing, and ten separate tools would mean ten places to maintain scoring, security and reporting. With one engine, a new instrument is a definition file, and the reliable change logic, the reports and the security model apply to it automatically.
Built through badania.org, my practice for custom psychometric instruments. The full build is written up in Building a Custom Diagnostic Panel for a Forensic-Psychiatry Clinic.