LIMS Admin Reference Ranges - hmislk/hmis GitHub Wiki

Reference Ranges

A reference range defines the normal expected value for a test parameter. When an MLT enters a result, the system compares it against the reference range and displays an H (high) or L (low) indicator if the value falls outside the range. Reference ranges are printed on the report alongside the result so the clinician can immediately see whether the value is normal. This article explains how to configure reference ranges per investigation item.

Where Reference Ranges Are Configured

Reference ranges are configured at the investigation item level. Each parameter within an investigation can have one or more reference ranges, differentiated by:

  • Age range (e.g., different ranges for neonates, children, adults, elderly)
  • Sex (e.g., different HGB ranges for males and females)

Adding a Reference Range

  1. Go to Menu > Admin > LIMS > Investigations.
  2. Open the investigation and navigate to the relevant item (parameter).
  3. Go to the Reference Ranges sub-tab (or click Add Reference Range).
  4. Fill in the following fields:
Field Description
Low value The lower bound of the normal range (e.g., 11.5 for haemoglobin in adult females)
High value The upper bound of the normal range (e.g., 16.5 for haemoglobin in adult females)
Unit Confirm the unit matches the item's unit (e.g., g/dL)
Sex Select Male, Female, or Any (leave as Any if the range applies to all sexes)
From age Minimum patient age for this range to apply (in years or months β€” depends on configuration)
To age Maximum patient age for this range to apply
  1. Click Save.

Setting Age-Specific Ranges

To cover all patient age groups for a parameter, add multiple reference range entries:

Age group From age To age Example low Example high
Neonate (0–28 days) 0 0.08 14.5 22.5
Infant (1 month–1 year) 0.08 1 10.5 14.0
Child (1–12 years) 1 12 11.0 15.5
Adult female 12 65 11.5 16.5
Adult male 12 65 13.0 18.0
Elderly 65 120 11.5 17.5

The system selects the matching range at report entry time based on the patient's age (calculated from date of birth) and sex. If no range matches, no H/L indicator is shown.

Setting Sex-Specific Ranges

For parameters where male and female ranges differ:

  1. Add two separate reference range entries β€” one with Sex = Male, one with Sex = Female.
  2. Set the same age range for both (or different age ranges if needed).
  3. The system automatically picks the correct range based on the patient's registered sex.

Reference Range Display on the Printed Report

The reference range relevant to the patient is printed on the report in the Reference column next to the result and H/L indicator. The lab administrator configures which reference range column to include in the report format.

Tips

  • Review reference ranges annually or whenever the lab adopts new clinical guidelines.
  • For paediatric haematology and biochemistry, pay close attention to age breakpoints β€” a missing age range means the system cannot display an indicator for that patient group.
  • Some parameters (e.g., serum creatinine) have ranges that differ significantly by age and sex β€” set up all combinations carefully.
  • Reference ranges for qualitative (categorical) results are not configured here β€” the "normal" value is determined by the categorical options themselves (e.g., "Negative" is normal for a urine protein test).

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