Life stages: purpose, design, and best practices
Creating a preset list of life stages streamlines order entry and supports clinically appropriate result interpretation. When modeled well, life stages help your LIS select the right tests, apply correct reference intervals, and generate clearer pathology and clinical reports.
Why capture life stages
- Order efficiency: Pre-filter or suggest tests and panels relevant to the patient’s stage (e.g., pediatric vs. adult; prenatal panels during pregnancy).
- Accurate reference intervals: Apply age-, sex-, puberty-, pregnancy-, or menopause-specific ranges for analytes whose normals shift with physiology.
- Clear reporting: Display stage context in reports (e.g., “Reference intervals: pregnancy, 2nd trimester”; “Pediatric range applied”).
- Decision support: Trigger reflexes, cautions, or alternative methodologies appropriate to the stage.
What to include in your preset list
Consider modeling life stage as two complementary dimensions rather than a single picklist:
Add optional qualifiers where clinically useful:
- Corrected gestational or postmenstrual age for preterm neonates
- Sex assigned at birth vs. administrative gender vs. hormone therapy status (for selecting ranges in endocrine tests)
- Surgical menopause or hysterectomy/oophorectomy status
Where life stages matter clinically (examples)
- Endocrine: TSH/Free T4 in pregnancy; LH/FSH/testosterone/estradiol across puberty and menopause.
- Chemistry: Alkaline phosphatase elevated in growth spurts; creatinine lower in pediatrics.
- Hematology: Hemoglobin/Hct vary in neonates and infants.
- Coagulation: D‑dimer and fibrinogen change during pregnancy.
- Toxicology/pharmacology: Dose/therapeutic ranges differ in pediatrics and geriatrics.
- Pathology: Cytology/histology comments may reference menopausal status or trimester.
Implementation approach in the LIS
Defaults and derivation
- Auto-derive age-based stage from date of birth at order entry.
- Infer pregnancy/trimester from ICD‑10 codes, prior results (e.g., hCG), or ordering provider input; allow explicit selection.
Workflow and UI
- Present a concise picklist with search and synonyms; require reproductive status only when relevant.
- Show the applied stage on results and include a note when ranges differ from standard adult intervals.
Interoperability
- HL7 v2: transmit life-stage context as structured observations (e.g., OBX with SNOMED CT code for pregnancy/trimester) or in OBX-8 comments when required by the receiver.
Governance and quality
- Define clear, non-overlapping age boundaries and document them.
- Keep a change log with effective dates; revalidate reference intervals when definitions change.
- Provide an override path with reason logging for edge cases (e.g., endocrine therapy, preterm corrected age).
- Train staff; include life-stage checks in order-entry QA and result validation.
Common pitfalls to avoid
- Using a single “life stage” field for everything, causing conflicts (e.g., “Adult” vs. “Pregnant, 2nd trimester”).
- Stale statuses (e.g., pregnancy not updated postpartum) leading to wrong ranges.
- Overly granular picklists that slow ordering; keep the UI concise and clinically meaningful.
- Ignoring sex/hormone status in tests where it matters (endocrine, iron studies, cardiac markers in pregnancy).
Quick start checklist
- Define your age-based buckets and reproductive statuses with codes and descriptions.
- Configure auto-derivation from DOB and prompt for reproductive status when applicable.
- Map tests to stage-partitioned reference intervals; load citations and effective dates.
- Expose stage context on reports and in interfaces.
- Audit quarterly for accuracy and update policies as needed.
Done well, a governed life-stage framework reduces ordering friction, improves clinical accuracy, and makes your reports more interpretable across EHRs and care teams.