Clinical Decision Support and Knowledge Management
CDS building blocks
Clinical decision support (CDS) is any person, process, or technology that gives clinicians, patients, or staff knowledge and person-specific information to improve decisions. The classic five rights are the right information, to the right person, in the right format, through the right channel, at the right time. Know the main modalities: alerts and reminders, order sets, templates, calculators, reference links, and predictive risk scores. Strong CDS is evidence-based, actionable, workflow-integrated, and maintainable; knowledge management covers authoring, review, versioning, and retirement.
Evidence and performance
Distinguish sensitivity, specificity, positive predictive value (PPV), and negative predictive value. PPV depends on prevalence, so a good test can yield many false positives in a low-prevalence population. Alert fatigue is a major safety problem: low-specificity alerts increase override rates and can train users to ignore important warnings. Evaluate CDS with process measures, outcomes, alert burden, and unintended consequences, not merely user satisfaction.
Traps
Questions often conflate sensitivity with PPV or imply that a statistically significant study proves local benefit. Another trap is assuming more alerts equal safer care; hard stops can cause workarounds. Predictive models need local validation, monitoring for drift, and a clear action plan.
Worked example / rule of thumb
A sepsis alert has 90% sensitivity and 90% specificity in a population with 10% sepsis prevalence. Of 1,000 patients, 100 have sepsis and 90 are detected; of 900 without sepsis, 90 are false positives. PPV = 90/(90+90) = 50%. Rule of thumb: design CDS around a decision and measure its effect; if the alert does not change an action, redesign or retire it.