Past Medical History (PMH) refers to a patient’s health status and medical events prior to their current health concern. It encompasses previous illnesses, operations, injuries, and treatments. While medical data is often perceived as factual, past medical history contains a subjective component. This article explores why.
Understanding Subjective and Objective Information
In healthcare, information is broadly categorized as either subjective or objective. Subjective information originates from the patient’s personal experience, perceptions, and feelings, such as pain descriptions or fatigue levels. This data is unique to the individual and cannot be directly observed or measured by a healthcare professional.
Objective information, conversely, is measurable, observable, and verifiable by others. This type of data includes vital signs, laboratory test results, and diagnostic imaging findings like X-rays or MRI scans. Objective data provides concrete evidence of a patient’s physical state. Both subjective and objective data are important for developing a complete picture of a patient’s health.
Why Past Medical History is Inherently Subjective
Past medical history is considered subjective because it relies heavily on a patient’s recall and interpretation of past events. Patients may remember major illnesses and treatments better than minor health issues, but various factors can influence the accuracy of their reporting. These factors include memory biases, the patient’s personal understanding of their symptoms, and their communication style.
Memory can be fallible, and patients may forget details or misinterpret past medical advice. Factors such as anxiety, the severity of a past illness, the time elapsed since the event, and even the patient’s education level can affect their ability to accurately recall medical history. Cognitive biases, such as anchoring bias or confirmation bias, can also influence how both patients and clinicians interpret and prioritize information.
How Healthcare Providers Use Subjective Past Medical History
Despite its subjective nature, past medical history is an important part of patient care and diagnosis. It provides context for current symptoms, helping healthcare providers identify patterns or connections relevant to a patient’s present condition. For example, understanding past responses to medications or therapies can guide current treatment planning.
Past medical history is also used for risk assessment, uncovering predispositions to certain conditions or identifying past adverse reactions. Knowledge of a patient’s health journey helps build a comprehensive understanding, informing preventive care strategies. While objective data offers measurable facts, the patient’s subjective narrative provides insights into their experience, thoughts, and feelings, which are valuable for personalized care.
Strategies for Effective History Taking
Healthcare professionals employ methods to gather accurate and useful information from a patient’s subjective past medical history. Active listening involves paying complete attention, showing interest, and refraining from interruption. This approach helps patients feel heard and understood, which encourages them to disclose more information.
Asking open-ended questions allows patients to describe their concerns freely, yielding more detailed information than simple yes/no questions. Follow-up questions help clarify details. Summarizing the patient’s answers confirms understanding and allows the patient to correct any misunderstandings. Cross-referencing information with available medical records, when consented, can also help verify details and provide a more complete picture.