Primary care practice provides comprehensive patient care including assessment, diagnosis and management of both acute and chronic problems. However, the ICD 9 coding system used in Canada does not capture the scope of disease or recognize the complexity of physician patient interactions. Administrative claims data in Canada use a single ICD-9 or ICD-10 code which does not elaborate on the severity of the disease, complexity of care or describe the extent of clinical management provided by the physician 12. Administrative claims data are most useful for providing a picture of the population's health problems and the functioning of the health care system, such as estimates of disease prevalence and services provided to patients (e.g. Canadian Institute for Health Information 3) rather than details of individual, patient level reports of care.

In the U.S, numerous studies have investigated the wide array of problems addressed and treatments provided during primary care encounters 45678. There have not been any Canadian studies to complement this data and therefore little is known about whether contextual differences such as funding mechanism or the predominance of family physicians in providing primary care alter the content of primary care encounters or the breadth of care provided by these physicians.

This study was initiated by a team of academic researchers and community-based family physicians with an interest in exploring the complexity of community-based care. In describing the content of primary care clinical encounters, this study's objectives were to identify the types of problems addressed by primary care physicians in a typical patient visit and to determine the kinds of actions taken and the various patient-related factors that influence visit complexity. These details are critically important in characterizing family practice, and in setting relevant educational, research, and policy priorities 7.

A total of 760 data collection forms were completed. The mean number of data collection forms returned by each physician was 47 but ranged from 9 to 114. In 85.1% of cases, the physicians reported they were responsible for the ongoing care of the patient. Female patients made up 71.5 percent of the total sample, while 76 percent of all the patients had some post -secondary education. The average age of the patients was 41; 18.6% were older than 65 years of age.

This study aimed to describe the content of a primary care clinical encounter and describe the breadth and complexity of primary care as well as the inadequacy of a single ICD-9 code required by and used in Canadian billing claims. The findings support previous research indicating that physicians commonly address multiple problems and provide numerous services during family practice outpatient visits. A mean of 2.56 topics were discussed per visit resulting in an average of over three actions. This finding corresponds with reports from previous studies in the US 46. as well as other countries 10. Beasley et al 4 reported an average of 3.05 problems among the general population with an increase to 3.88 problems among patients over 65 years of age. Several additional studies using direct observation reported an average of 1.8-2.7 problems among their general patient population but as many as 58% of visits underreported the number of problems encountered 6.

The number of topics discussed per visit is associated with physicians reporting a clinical encounter to be complex. Considering that 90% of patients visiting their family physician have more than one chronic condition, and as many as 50% have five or more 11, primary care visits are more complex than the current coding practice indicates.

Most chronic conditions are managed within family practice with a small percentage of actions resulting in a referral to a specialist. Comorbidity is frequently addressed in the primary care encounter and primary care providers are the case managers for most patients with comorbidities as specialist care is sought for uncommon conditions 12. Primary care providers are aware of the growing complexity of care expected outside of specialist care. The likelihood of this leading to physician burnout has been suggested 13.

Our data collection form gave the physicians an opportunity to list up to seven topics addressed during the visit, however only a single ICD code is submitted in most Canadian reimbursement systems and should reflect the primary problem addressed. The ICD-9 code did not consistently correspond to the problems considered dominant during the patient visit. They also did not consistently correspond to the problems that take the most time to address in a visit. In addition, episodic/acute visits were the most prevalent type of visits yet ICD-9 codes for general medical examinations or chronic disease management were the most frequently used diagnostic codes. This lack of congruence between codes and topics appears to be strongly related to whether visits were more complex visits (with multiple problems covered) rather than less complex or more symptom focused (Table 2). However, the use of a single ICD-9 code per interaction may potentially overstate the prevalence of chronic disease management. While research using administrative databases often use algorithms which incorporate other data sources, such as hospital discharge data or prescription drug use to manage the shortcomings of ICD-9 coding, 14 these do not account for the complexity of any particular visit nor do they identify the most important clinical activities. Thus, the use of a coding system that is not sensitive to the breadth and complexity of primary care encounters (such as ICD-9 codes) contributes to a distorted understanding of primary care encounters.

ICD coding originated for the purpose of categorizing and coding morbidity for public health purposes and until the mid 1970's was the most common means of classifying morbidity data within primary care. However, with its disease-based structure, many of the vague and/or ill defined symptoms and non-disease conditions that present in primary care are difficult to code with ICD codes. The disadvantages in using ICD spurred the World Organization of Family Doctors (WONCA) to design a classification specific to primary care. The International Classification of Primary Care (ICPC) provides a more comprehensive and patient centred structure while also ordering the data according to episodes of care (or first to last presentation of an illness or event) 15. Structuring the data by utilizing episodes of care may allow greater recognition of the complexity of primary care encounters as well as recognizing the relationship of episodes across encounters 16.

The comprehensive care that is provided by family physicians is of particular relevance as we move toward care that is oriented toward the patient's overall health rather than disease-centered care. A broader view of patient care must be considered if primary care is to be properly understood. Effective multimorbidity case management requires an approach that cannot be neatly categorized into a discrete ICD diagnostic code. A more holistic approach to caring for patients with multiple morbidities requires moving beyond codes or labels and considering varying levels of severity and emotional distress that accompany their conditions 17. Furthermore, effective quality care considers the patients' concerns and requires time for careful listening, planning and negotiating - valued aspects of holistic care and greater patient satisfaction 18. The patient-centered medical home concept prioritizes accessible, comprehensive coordinated medical care 19. To advance this concept, there is a need for greater understanding of complexity measures 13 and related factors as well as greater specificity in how primary care is characterized within coding schemes. The limitations of ICD coding in describing the content of the primary care visit have become evident within the encounter data collected in this study. The shortcomings of ICD are further exacerbated by the current reporting of a single ICD code in Canada. Clearly, it is time for a coding system that will more accurately document the provision of patient care, disease-related complications and resource utilization in primary care 2. Funding and system reform priorities set on the basis of administrative data alone cannot describe the complex management of patient problems within a context of competing demands and will likely miss significant primary care practice considerations.

This is one of the first Canadian studies to critically analyze the content of primary care clinical encounters. The data allowed a greater understanding of primary care clinical encounters and attests to the deficiencies of singular ICD-9 or billing coding. Therefore, as primary care reform initiatives in the U.S and Canada attempt to transform the way family physicians deliver care, it becomes increasingly important that physicians, researchers and policy makers develop a thorough understanding of the breadth and complexity of primary care encounters.

The authors declare that they have no competing interests.

AK and MD were involved in the conception and design of the study. GH and JS were involved in data analysis and manuscript drafting with significant contributions from both AK and MD. All authors reviewed drafts, contributed to revisions and approved the final manuscript.