Query: What did my last laboratory test show?, FHIR Resource: {'resourceType': 'Observation', 'status': 'final', 'category': [{'coding': [{'system': 'http://terminology.hl7.org/CodeSystem/observation-category', 'code': 'laboratory', 'display': 'Laboratory'}]}], 'code': {'coding': [{'system': 'http://loinc.org', 'code': '5802-4', 'display': 'Nitrite [Presence] in Urine by Test strip'}], 'text': 'Nitrite [Presence] in Urine by Test strip'}, 'subject': {'reference': 'urn:uuid:0cf5bca8-884d-9dd9-c2d0-5b232dfbb573'}, 'effectiveDateTime': '2024-02-28T16:42:05+05:30', 'valueQuantity': None, 'interpretation': None}