Introduction

Obtaining a patient's medical history is one of the most important tasks in medicine. Taking a good medical history helps trigger further questions and investigations, and focuses the clinical assessment by narrowing down the search space dramatically. Furthermore, a medical history is almost always a requirement before making diagnoses and suggesting treatments.

Here, I describe a standard medical history, but please keep in mind that a good medical history will adapt to the patient's presenting circumstances and the relevant medical specialty. For example, the history for a chronic medical condition would explore more of the patient's self-management, response to treatment, and quality of life. Also, for example, a psychiatric history will be markedly different from an obstetric history, focusing more on mental status, cognition, mood, etc.

The following is a framework for interactive history taking, but the descriptions and categories may also be useful for the summarization and classification of transcribed patient encounters. I see potential applications for tools in virtual medicine, or even automated medical diagnoses. Let's jump right in!

Medical History Taking

Metadata

It's always a good idea to start by confirming and documenting the patient's name, date of birth, gender, and how they wish to be addressed. Also, record the time and date of the history. If the medical history is not directly from the patient, but a second-hand report, this should be indicated along with the source of the information. If relevant, document the reliability of the history. For example, "vague symptom descriptions" or "conflicting details".

Interviewer Role

In an interview setting, both the order and style of questioning must be considered. In terms of ordering, it's best to complete the current category of questioning before moving on to the next one. This helps keep the interview focused and feel less jumpy. The ordering of the medical categories listed below is not strict, but is a good starting point. If the conversation unintentionally touches on a different category, the interviewer can either switch now and come back to the original category later, or inform the patient that they will explore the different category later. The interviewer is also responsible for keeping the interview on track, making sure that the interview does not stray off into trivial details or irrelevant stories. This can be done with a gentle reminder to stay focused, or a request to talk about it at a later time.

In terms of questioning style, always start off with open-ended questions that provide a broader overview of the patient. Later, the interviewer can dig deeper with specific questions that allow for a better understanding of the patient, or help with the diagnoses. Also, the interviewer is responsible for providing empathy and building rapport with the patient, affirming the patients statements and feelings. The interviewer should try to understand how the patient feels, and provide appropriate verbal and non-verbal responses. This is not something that can be easily learned through a blog post 😃. Many other skills are useful during an interview, for example: providing multiple options for a question, clarifying and echoing the patient, good transitioning between categories.

1. Presenting Complaint

The presenting complaint is the symptom or concern causing the patient to seek care. A good mnemonic to help elucidate a complete history of the presenting complaint is OLDCARTS. The abbreviation stands for Onset, Location, Duration, Characteristics, Alleviating/Aggravating factors, Radiation, Timing, Severity. After asking OLDCARTS, the interviewer should ask about any associated symptoms, and any coinciding events that could have triggered the issue. Ask if the symptoms have evolved over the duration of the complaint, and if similar episodes have occurred in the past, with comparisons. This is a good time to ask questions that can help narrow down the diagnoses.

2. Review of Systems (ROS)

This involves asking the patient questions about the major body systems, from head to toe. The specific ROS questions will differ greatly between interviewers, so I will only provide a basic list of the body systems and one or two example questions for each. Please note, these example questions are not representative of a complete history of each body system.

It's completely fine for the interviewer to simply ask if the body system in question is causing issues, e.g. "Any issues with urination?". However, some patients will need specific questions since they may not be aware of an issue, or cannot easily recall symptoms from memory. Warn the patient that this will essentially be a series of yes-no questions.

Neurological: Changes in memory or cognition, dizziness

Vision: Blurry vision, Double vision

Hearing: Difficulty hearing, Ringing in ears

Smell/Taste: Difficulty smelling or tasting

Cardiovascular: Chest pain, Heart palpitations

Respiratory: Cough, Sputum production (mucus)

Gastrointestinal: Nausea or vomiting, Change in bowel movements

Reproductive: Menstrual health, STI symptoms

Urinary: Urgency or frequency, Pain while urinating

Muscles/Bones/Joints: Weakness, swelling

Skin: Rashes

Finally, the interviewer should ask about Sleep, Weight, Appetite, Energy (SWAE mnemonic), as well as B-symptoms. B-symptoms are defined as the presence of fever, unintentional weight loss, and night sweats, and are recognized as a predictor for certain types of cancers (specifically lymphoma).

3. Past Medical History (PMHx)

Ask about any illnesses that are ongoing, or have been diagnosed in the past, including childhood illnesses and any birth defects. Inquire about previous hospitalizations and surgeries. Ask about previous and current medications, over-the-counter (OTC) drugs, and supplements. Document the patient's allergies and immunizations.

4. Family History

For this, the interviewer should ask about the health and medical conditions affecting the patient's parents or family. For example, some families have a history of diabetes, cardiovascular illness, or cancer. Note that some genetic conditions require an extended family tree (pedigree) to properly diagnose. If any members of the patient's family are deceased, inquire about the cause of death. The interviewer can also ask if there were any family members who passed away during childhood.

5. Ideas, Feelings, effect on Function, Expectations (IFFE)

This category explores less of the medical aspects, and more of a patient's perceptions and feelings during the interview. Ask about what the patient thinks may be causing the issue. Ask how the patient feels, and why. Explore the patient's fears, and attempt to resolve any that can be easily resolved. Ask about how this is affecting the patient's day-to-day functioning. Lastly, ask what the patient expects out of this interaction. Overall, this not only helps uncover more information about the cause of the complaint, but can also help guide treatment down the line. Furthermore, these questions helps strengthen rapport between the patient and interviewer, which is beneficial when asking personal questions during the next category.

6. Personal and Social History

This is a chance for the interviewer to explore the patient's personal life and relationships. Start off with questions about the patient's occupation, level of education, and hobbies. Inquire about the patient's home status, their partner(s), and relationships to their family and friends. Explore the patient's stressors, including their finances if applicable. Ask about the patient's exercise and diet habits. Finally, perform a history on their sexual health/activity, and their drugs, alcohol, and nicotine use. Interviewers can ease patient discomfort by stating that these questions are asked to all patients. Lastly, when interviewing elderly or disabled persons, include questions about Activities of Daily Living (ADLs).

7. Focused Questions

Although not a true category on its own, this is a chance for the interviewer to ask questions that they may have missed. It is common for questions to be generated after receiving all the information above, since the list of potential diagnoses could have changed. These questions can include anything from more specific symptoms, environmental exposures, or recent travel history.

Concluding the Interview

Every interviewer has their own style of concluding the interview, however the following method is common. First, summarize the patient's concerns and symptoms. Then describe any plans for treatment or further investigations. For example, the medical history may be followed by a physical examination. Next, ask if the patient has any questions. Finally, schedule a follow-up visit, if needed.

References

Bickley, L., Szilagyi, P., Hoffman, R., Bates’ Guide to Physical Examination and History Taking (12e)

Also, a big thank you to Brendan for his feedback on this blog post!