Safety of care

Improving patient safety and reducing risks

Co-morbidities — Have you considered all health conditions?

Originally published March 2013

Physicians must manage their patients' primary health concerns, while also considering other coexisting conditions. Obesity and diabetes, for example, are common co-morbid medical conditions that exist with other diseases and may impact care. By maintaining a heightened awareness of how these conditions affect patient health, physicians can help improve outcomes for their patients.

Over a 5-year period, from 2007 to the end of 2011, the CMPA had 4,288 legal and medical regulatory authority (College) closed cases where a patient's co-morbidity was noted. A review of the cases focused on those where the patient's co-morbidities may have affected the care or outcome.  The cases were identified as either surgical or non-surgical.

What is a co-morbidity?

Co-morbidity is defined as the existence or history of a relevant disease or medical condition that is present during care but is not the primary reason for seeking care at the time. Non-medical conditions, such as smoking, are also included as co-morbidities in the cases reviewed.

Surgical cases

Co-morbidities were documented in 522 surgical cases of which 77% were legal actions and 23% were College complaints. Obesity, smoking, and diabetes were the co-morbidities with the greatest impact on the patient's condition or care. The physicians most often involved in these cases were general surgeons, followed by orthopaedic surgeons and gynecologists. The outcome for physicians was favourable in the majority of legal and College cases, although some legal cases were settled when the care could not be supported by peer experts.  

Pre-operative setting

A deficient assessment and a failure to refer a patient were common pre-operative issues in the cases studied. Experts in these cases maintained that the physicians should have taken the time to better assess the patients with multiple medical problems (e.g. diabetes, chronic obstructive pulmonary disease [COPD], history of myocardial infarction [MI], and hypertension), or should have referred the patients to specialists for further diagnostic examination.

For example, in one case a woman with diabetes and hypertension developed a wound infection following mastopexy. Experts were of the opinion she should have been referred to an internist for a pre-operative assessment.

In another case, an obese diabetic patient with advanced peripheral vascular disease had elective hip arthroplasty and then developed an infected necrotic heel ulcer followed by infective endocarditis. He required a below-knee amputation and a mitral valve replacement. Experts were critical of the orthopaedic surgeon's decision to proceed with elective surgery on a patient with a significant vascular compromise.

As one expert stated, ideally a surgeon should be aware of any significant medical problem prior to operating on a patient.

The consent discussion and its documentation were also issues, particularly in relation to how a patient's co-morbidities could increase surgical risk and the risk of post-operative complications.

Intra-operative setting

Injury (e.g. bowel, blood vessel, ureter) was the main intra-operative issue encountered during surgery. Most of these surgeries were deemed technically difficult due to co-morbidities such as the patient's obesity or adhesions from previous surgery. In many of the cases, the experts were supportive of the surgeon's care as the injuries were recognized as inherent risks of the surgery. In other cases, the experts felt the surgeon should have converted the surgery from a laparoscopic to open approach when difficulties were encountered. 

Post-operative setting

Diagnostic delay of post-operative complications and premature discharge were the main issues identified in the post-operative period.

Some of these issues are illustrated in the case of a patient who was recovering from a hemicolectomy. Over the course of 5 days, the patient, who was on long-term steroid therapy for systemic lupus erythematosis, developed low-grade fever with chills and an elevated white blood count that then normalized. An anastomotic leak was diagnosed with CT scan. Despite surgery for this, the patient succumbed to sepsis, multi-system failure, and coagulopathy. Following a complaint initiated by the family, the College counselled the surgeon to sufficiently inform patients about the risks associated with surgery and post-operative complications, as well as to be more vigilant about monitoring an immunosuppressed patient for post-operative complications.

A second case further demonstrates the impact of post-operative issues. A patient, with 2 prior episodes of pulmonary embolus (PE), was kept in hospital overnight after developing low oxygen saturation levels of 86% post-hemithyroidectomy. Two days after her discharge, she was diagnosed with PE. Experts were critical that the patient in this case was not referred to a hematologist before surgery, and the desaturation was not investigated prior to discharge.

Non-surgical cases

Co-morbidities were documented in 1,175 non-surgical cases in this series, of which 39% were legal and 61% were College cases. The most common co-morbidities found to have affected the patient's care or outcome were diabetes, ischemic heart disease, hypertension, and smoking. The types of physicians most involved were family physicians, psychiatrists, and emergency physicians. Physician outcomes for the non-surgical cases were comparable to the surgical cases — that is, the outcomes were favourable in the majority of legal and College cases, although some legal cases were settled when the care could not be supported by peer experts.

Diagnostic issues predominated, with the steps of assessment and follow-up being most problematic.


In many cases, peer experts stated that an appropriate patient history should have been taken and a thorough physical examination should have been performed. Problems identified included failure to consider a patient's pre-existing conditions and focusing on particular symptoms that resulted in missed or delayed diagnoses, particularly in cases of acute coronary syndrome (ACS).

In one case, for example, a middle-aged obese smoker, with a history of MI and recent stress, presented with his second episode in a week of intense epigastric pain radiating to the back after eating a fatty meal. This pain was accompanied with belching and vomiting. The physician's differential diagnoses were peptic ulcer and gallbladder disease, which delayed the diagnosis of ACS and contributed to the patient's death.

In another case, an elderly woman with a history of smoking, hypertension, and asthma was discharged from the emergency department with a diagnosis of possible COPD after presenting earlier that day with increased shortness of breath. Before she could return the following morning for further investigations, she died from ACS.

In both situations, experts were critical of the physicians for failing to consider other diagnoses in patients with significant co-morbidities.

Follow-up management

In managing follow-up, the main issue identified by experts was a delay or failure to follow up on a patient's condition or tests.

In one illustrative case, a physician examined a patient's knee following a fall. The examination was difficult due to the patient's morbid obesity and significant pain. Detecting a possible tibial plateau injury on the plain knee X-ray, the physician consulted a radiologist who was unsure if the injury was old or new. The radiologist suggested re-examining the patient to determine the location and extent of tenderness before doing further imaging, but this was not done. As the patient confirmed a previous knee injury in the preceding year, the fracture was considered old and the patient was discharged with crutches and an orthopaedic consult was booked for a few weeks later. The patient was later diagnosed with an impacted tibial plateau fracture with an effusion, and a compartment syndrome. Experts were critical of the care of this patient who was experiencing pain out of proportion to an identified injury; they noted that the knee and leg were not re-examined before discharge, further imaging was not done to better clarify the nature of the injury or alternatively a same-day orthopaedic consult was not requested, and discharge instructions were not documented.

In another case that illustrates issues in managing follow-up, a patient with hyperlipidemia and a family history of cardiac disease visited his family doctor complaining of neck pain with paresthesias in his left hand. He was diagnosed with cervical disc disease. One month later, the patient died suddenly from atherosclerotic coronary artery disease. After consideration of the history in this case, the neck pain was considered an anginal equivalent. The College counselled the physician to consider cardiac risk factors more seriously and be more aggressive in risk factor modification (e.g. statin therapy).

Risk management considerations

Based on the experts' opinions in these cases, the following approaches support the managing of risk when caring for patients with co-morbidities.

  1. An adequate history including pre-existing conditions should be obtained from patients and an appropriate physical examination should be conducted. The patient should be provided with the opportunity to express his or her current health concerns. If required, the appropriate specialists should be consulted.
  2. Any relevant risk factors, including family history, that could have an impact on the patient's care, should be adequately considered.
  3. A patient's relevant medical history should be considered before starting treatment.
  4. The consent discussion should contain appropriate information on the risks and benefits of the proposed surgical procedure or treatment. The discussion should include how a patient's pre-existing conditions could increase risks of intra-operative and post-operative complications. If there are any potential alternative therapies, these should also be reviewed. The patient should be given the chance to ask questions and the discussion should be adequately documented in the medical record.
  5. A method to identify the patient's pre-existing conditions in the medical record should be established.
  6. A reliable process should be in place to facilitate timely follow-up of investigations.

DISCLAIMER: The information contained in this learning material is for general educational purposes only and is not intended to provide specific professional medical or legal advice, nor to constitute a "standard of care" for Canadian healthcare professionals. The use of CMPA learning resources is subject to the foregoing as well as the CMPA's Terms of Use.