Definition and Considerations

CPGs are formulated by expert multidisciplinary panels that review existing literature and make consensus recommendations based on the strongest available evidence. The IOM defines CPGs as “statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options.” Stated another way, CPGs are consensus-based recommendations for patient care that are based on the best available evidence; their purpose is to empower individual physicians to deliver optimal evidence-based care to their patients.

CPGs are limited by the quality of available evidence; the literature can be classified into 5 levels of evidence from strongest (level 1) to weakest (level 5) ( Table 1 ). The National Comprehensive Cancer Network (NCCN) has addressed this by categorizing their recommendations based on the strength of available evidence and the degree of consensus among panel members ( Table 2 ); because the availability of level 1 data from randomized prospective clinical trials is limited, most guidelines for head and neck cancer care are based on a lower level of evidence with uniform NCCN consensus. In the United Kingdom, the Scottish Intercollegiate Guidelines Network (SIGN) assigns each recommendation both a numeric score denoting the level of evidence and a letter grade indicating the strength of the recommendation. Although most recommendations for head and neck cancer are based on a lower level of evidence, level 1 studies have significantly changed NCCN guidelines for head and neck cancer.

Because CPGs are created by an expert multidisciplinary panel, there is the potential for conflicts of interest among panel members; panelists may be biased by their own publications, inherent treatment philosophy, and research interests or by industry affiliations. The IOM recently recognized this problem by establishing criteria for identifying high-quality CPGs. This report emphasized the need for limitation and full disclosure of any conflicts of interest among panel members and transparency surrounding the development of CPGs. Other investigators have suggested including unbiased methodologists in the expert panel, although their exact roles have yet to be defined.

Another consideration when formulating CPGs is the target patient and physician populations; guidelines must take into account differences in the patient case mix and resources accessible by physicians, in addition to social and cultural factors. Regional differences in CPGs for the same disease may reflect these variations.

Opponents of CPGs argue that they restrict physicians’ autonomy in practicing medicine by dictating algorithms of care. In reality, CPGs are created to provide a framework and foundation on which individualized patient management can be constructed subject to several factors including the patient’s performance status and personal desire. The NCCN explicitly states that physicians are “expected to use independent medical judgment in the context of individual clinical circumstances to determine a patient’s care or treatment.”

Importance in Daily Practice

The recent emphasis on evidence-based medicine has resulted in a proliferation of clinical publications, making it increasingly more difficult to keep up with the most current literature. Physicians are not only expected to read these studies but they are also expected to evaluate the strength of the evidence and the potential impact on clinical practice. In addition, the capability of otolaryngologists to understand and critique literature has yet to be determined. CPGs serve the purpose of presenting physicians with practice recommendations based on the best available evidence and expert consensus; physicians can then individualize the care they deliver built on the framework offered by CPGs.

Role in Quality Assessment

The IOM has recommended developing a set of core quality measures to evaluate and monitor the quality of cancer care ; currently, quality metrics for the management of oral cavity and larynx cancers (but not oropharyngeal cancers) have been developed but are not yet validated. Since CPGs are built on the best available evidence, they can establish standards of care, designate quality indicators, and set priorities for quality improvement initiatives.

Recently, Hessel and colleagues established 4 main quality measures and 26 clinical end points based on institutional and NCCN guidelines, using these to evaluate the care delivered to patients with oral cavity cancers in a tertiary level of care department. The investigators reported an 88% or greater compliance with the 4 main quality metrics but more variable results for the clinical end points, thereby identifying areas of improvement. Lewis and colleagues used NCCN guidelines as a quality standard to evaluate the care received by patients with head and neck cancers referred to a tertiary care center with recurrent or persistent disease, finding that 43% of these patients had prereferral care that deviated from NCCN guidelines. In these instances, guidelines served to delineate specific metrics and act as a quality standard ; being built on the best available evidence enables CPGs to have versatility in providing quality metrics.

Implications for Changing Policy

There has been recent emphasis on limiting the overuse of medical interventions with no proven benefit and the underuse of those with proven efficacy. Because CPGs identify the most appropriate practices based on the best available evidence, they have a pivotal role in national quality initiatives and may potentially affect reimbursement policies.

This role of CPGs has been demonstrated most clearly in the United Kingdom. In 1999, the National Institute for Health and Clinical Excellence (NICE) was established by the National Health Service (NHS) of England and Wales to develop CPGs, which are then published as general guidelines. In addition, NICE makes recommendations to the NHS about reimbursement for medical interventions based on safety, clinical effectiveness, and cost, which are related to the CPGs they develop. This system is facilitated by the presence of universal health care; the United States, with its medley of private payers, has no such parallel agency. The Centers for Medicare and Medicaid Services have begun pay-for-performance programs derived from evidence-based quality indicators and not from specific CPGs, although none currently apply to head and neck cancer care.

Pay-for-performance programs rely on specific performance indicators; there are no such standardized metrics for head and neck surgery, although this may soon change. Weber and colleagues identified head and neck surgical performance measures based on those in the general surgery literature that include length of stay, perioperative wound infections, mortality, return to the operating room within 7 days of index surgery, and readmission within 30 days of discharge. An intradepartmental review of more than 2500 cases demonstrated that individual surgeon, patient comorbidities, and procedure acuity significantly affected the prevalence of negative performance indicators. Although these metrics have yet to be standardized, such indicators may be tied to future performance incentives. Limited evidence, the flexibility inherent to CPGs, and identifying who would receive the incentive currently hinder the use of CPGs for this purpose, but may be overcome if incentives are prorated based on the priority of the measure and guideline goals are made more explicit.