Parse lab values that include a range

frontend/src/app/components/fhir-card/common/observation-bar-chart/observation-bar-chart.component.ts

@@ -15,7 +15,7 @@ const defaultChartEntryHeight = 30;
   styleUrls: ['./observation-bar-chart.component.scss']
 })
 export class ObservationBarChartComponent implements OnInit {
-  @Input() observations: [ObservationModel]
+  @Input() observations: ObservationModel[]
 
   chartHeight = defaultChartEntryHeight;
 
@@ -122,14 +122,21 @@ export class ObservationBarChartComponent implements OnInit {
       return;
     }
 
-    let currentValues: number[] = []
+    let currentValues = []
     let referenceRanges = []
 
     for(let observation of this.observations) {
       let refRange = observation.reference_range;
 
       referenceRanges.push([refRange.low || 0, refRange.high || 0]);
-      currentValues.push(observation.value_quantity_value);
+
+      let value = observation.value_object;
+
+      if (value.range) {
+        currentValues.push([value.range.low, value.range.high]);
+      } else {
+        currentValues.push([value.value, value.value])
+      }
 
       if (observation.effective_date) {
         this.barChartLabels.push(formatDate(observation.effective_date, "mediumDate", "en-US", undefined));
@@ -141,7 +148,7 @@ export class ObservationBarChartComponent implements OnInit {
       this.barChartData[1]['dataLabels'].push(observation.value_quantity_unit);
     }
 
-    let xAxisMax = Math.max(...currentValues) * 1.3;
+    let xAxisMax = Math.max(...currentValues.map(set => set[1])) * 1.3;
     this.barChartOptions.scales['x']['max'] = xAxisMax
 
     let updatedRefRanges = referenceRanges.map(range => {
@@ -154,7 +161,7 @@ export class ObservationBarChartComponent implements OnInit {
 
     // @ts-ignore
     this.barChartData[0].data = updatedRefRanges
-    this.barChartData[1].data = currentValues.map(v => [v, v])
+    this.barChartData[1].data = currentValues
 
     this.chartHeight = defaultChartHeight + (defaultChartEntryHeight * currentValues.length)
   }

frontend/src/app/components/fhir-card/common/observation-bar-chart/observation-bar-chart.stories.ts

@@ -33,6 +33,12 @@ export const NoRange: Story = {
   }
 };
 
+export const ValueStringWithRange: Story = {
+  args: {
+    observations: [new ObservationModel(observationR4Factory.valueString('<10 IntlUnit/mL').referenceRangeOnlyHigh(50).build(), fhirVersions.R4)]
+  }
+};
+
 export const Range: Story = {
   args: {
     observations: [new ObservationModel(observationR4Factory.referenceRange().build(), fhirVersions.R4)]

frontend/src/lib/fixtures/factories/r4/resources/observation-r4-factory.ts

@@ -9,6 +9,18 @@ class ObservationR4Factory extends Factory<{}> {
     })
   }
 
+  valueQuantity(params: {}) {
+    return this.params({
+      valueQuantity: {
+        value: params['value'] || 6.3,
+        unit: params['unit'] || 'mmol/l',
+        system: 'http://unitsofmeasure.org',
+        code: params['code'] || 'mmol/L',
+        comparator: params['comparator']
+      }
+    })
+  }
+
   referenceRange(high?: number, low?: number) {
     return this.params({
       referenceRange: [

frontend/src/lib/models/resources/observation-model.spec.ts

@@ -8,6 +8,35 @@ describe('ObservationModel', () => {
   });
 
   describe('parsing value', () => {
+    it('reads from valueQuantity.value if set', () => {
+      let observation = new ObservationModel(observationR4Factory.build(), fhirVersions.R4);
+
+      expect(observation.value_object.value).toEqual(6.3);
+    });
+
+    it('parses valueString correctly when value is a number if valueQuantity.value not set', () => {
+      let observation = new ObservationModel(observationR4Factory.valueString().build(), fhirVersions.R4);
+
+      expect(observation.value_object.value).toEqual(5.5);
+    });
+
+    it('parses value correctly when valueQuantity.comparator is set', () => {
+      let observation = new ObservationModel(observationR4Factory.valueQuantity({ comparator: '<', value: 8 }).build(), fhirVersions.R4);
+      let observation2 = new ObservationModel(observationR4Factory.valueQuantity({ comparator: '>', value: 8 }).build(), fhirVersions.R4);
+
+      expect(observation.value_object).toEqual({ range: { low: null, high: 8 } });
+      expect(observation2.value_object).toEqual({ range: { low: 8, high: null } });
+    });
+
+    it('parses value correctly when valueString has a range', () => {
+      let observation = new ObservationModel(observationR4Factory.valueString('<10 IntlUnit/mL').build(), fhirVersions.R4);
+      let observation2 = new ObservationModel(observationR4Factory.valueString('>10 IntlUnit/mL').build(), fhirVersions.R4);
+
+      expect(observation.value_object).toEqual({ range: { low: null, high: 10 } });
+      expect(observation2.value_object).toEqual({ range: { low: 10, high: null } });
+    });
+
+    // following two tests being kept temporarily. will be removed in next PR when I remove value_quantity_value
     it('reads from valueQuantity.value if set', () => {
       let observation = new ObservationModel(observationR4Factory.build(), fhirVersions.R4);
 
@@ -21,6 +50,7 @@ describe('ObservationModel', () => {
     });
   });
 
+
   describe('parsing unit', () => {
     it('reads from valueQuantity.unit if set', () => {
       let observation = new ObservationModel(observationR4Factory.build(), fhirVersions.R4);

frontend/src/lib/models/resources/observation-model.ts

@@ -1,6 +1,6 @@
 import {fhirVersions, ResourceType} from '../constants';
 import * as _ from "lodash";
-import {CodableConceptModel, hasValue} from '../datatypes/codable-concept-model';
+import {CodableConceptModel} from '../datatypes/codable-concept-model';
 import {ReferenceModel} from '../datatypes/reference-model';
 import {FastenDisplayModel} from '../fasten/fasten-display-model';
 import {FastenOptions} from '../fasten/fasten-options';
@@ -10,12 +10,19 @@ interface referenceRangeHash {
   high: number | null
 }
 
+// should have one or the other
+export interface ValueObject {
+  range?: { low?: number | null, high?: number | null }
+  value?: number | string | boolean | null
+}
+
 export class ObservationModel extends FastenDisplayModel {
   code: CodableConceptModel | undefined
   effective_date: string
   code_coding_display: string
   code_text: string
-  value_quantity_value: number
+  value_object: ValueObject
+  value_quantity_value
   value_quantity_unit: string
   status: string
   value_codeable_concept_text: string
@@ -34,7 +41,8 @@ export class ObservationModel extends FastenDisplayModel {
     this.code = _.get(fhirResource, 'code');
     this.code_coding_display = _.get(fhirResource, 'code.coding.0.display');
     this.code_text = _.get(fhirResource, 'code.text', '');
-    this.value_quantity_value = this.parseValue();
+    this.value_object = this.parseValue();
+    this.value_quantity_value = this.value_object?.value;
     this.value_quantity_unit = this.parseUnit();
     this.status = _.get(fhirResource, 'status', '');
     this.value_codeable_concept_text = _.get(
@@ -55,29 +63,77 @@ export class ObservationModel extends FastenDisplayModel {
     this.subject = _.get(fhirResource, 'subject');
   }
 
-  private parseValue(): number {
-    // TODO: parseFloat would return NaN if it can't parse. Need to check and make sure that doesn't cause issues
-    return this.valueQuantity() || parseFloat(this.valueString())
+  private parseValue(): ValueObject {
+    return this.parseValueQuantity() || this.parseValueString()
   }
 
   private parseUnit(): string {
     return this.valueUnit() || this.valueStringUnit()
   }
 
   // Look for the observation's numeric value. Use this first before valueString which is a backup if this can't be found.
-  private valueQuantity(): number {
-    // debugger
-    return _.get(this.fhirResource, "valueQuantity.value");
+  private parseValueQuantity(): ValueObject {
+    let quantity = _.get(this.fhirResource, "valueQuantity");
+
+    if (!quantity) {
+      return null;
+    }
+
+    switch (quantity.comparator) {
+      case '<':
+      case '<=':
+        return { range: { low: null, high: quantity.value } };
+      case '>':
+      case '>=':
+        return { range: { low: quantity.value, high: null } };
+      default:
+        return { value: quantity.value }
+    }
   }
 
   // Look for the observation's numeric value. Use this first before valueStringUnit which is a backup if this can't be found.
   private valueUnit(): string {
     return _.get(this.fhirResource, "valueQuantity.unit");
   }
 
-  // Use if valueQuantity can't be found. This will check for valueString and attempt to parse the first number in the string
-  private valueString(): string {
-    return _.get(this.fhirResource, "valueString")?.match(/(?<value>[\d.]*)(?<text>.*)/).groups.value;
+  private parseValueString(): ValueObject {
+    let matches = _.get(this.fhirResource, "valueString")?.match(/(?<value1>[\d.]*)?(?<operator>[^\d]*)?(?<value2>[\d.]*)?/)
+
+    if(!matches) {
+      return { range: { low: null, high: null } }
+    }
+
+    if (!!matches.groups['value1'] && !!matches.groups['value2']) {
+      return {
+        range: {
+          low: parseFloat(matches.groups['value1']),
+          high: parseFloat(matches.groups['value2'])
+        }
+      }
+    }
+
+    if (['<', '<='].includes(matches.groups['operator'])) {
+      return {
+        range: {
+          low: null,
+          high: parseFloat(matches.groups['value2'])
+        }
+      }
+    } else if (['>', '>='].includes(matches.groups['operator'])) {
+      return {
+        range: {
+          low: parseFloat(matches.groups['value2']),
+          high: null
+        }
+      }
+    }
+    let float = parseFloat(matches.groups['value1']);
+
+    if (Number.isNaN(float)) {
+      return { value: matches.groups['value1'] }
+    }
+
+    return { value: float };
   }
 
   // Use if valueUnit can't be found.