Use and overuse of diagnostic neck ultrasound in Ontario: Retrospective population-based cohort study.

OBJECTIVE: To provide an overview of the use and possible overuse of diagnostic neck ultrasound (DNUS) by describing and comparing both the ordering rates and the downstream results of DNUS by regions across Ontario. DESIGN: Retrospective population-based cohort study based on electronic health care data. SETTING: Ontario. PARTICIPANTS: Ontario residents (adults aged > 18 years) who had a diagnosis of thyroid cancer between October 1, 1999, and June 30, 2014, and residents who had a DNUS in 2012. MAIN OUTCOME MEASURES: Proportion of Ontario residents in each sub-Local Health Integration Network (LHIN) group who had their first DNUS in 2012 and went on to other relevant tests, diagnoses, and surgery. The sub-LHIN groups were based on increasing age- and sex-adjusted rates of first DNUS. RESULTS: There were 77 238 DNUS tests in 2012 and there was a 7.4-fold variation in the rate of test ordering across the sub-LHIN populations leading to variable rates of actual disease, suggesting screening or uncertain indications for tests. CONCLUSION: Across Ontario, the indications for ordering DNUS are variable, and screening or testing without indication might be a common practice. Establishing effective guidelines for the ordering of DNUS would potentially reduce costs and ultimately reduce the rates of thyroid cancer.

A Population-Based Study on NIFTP Incidence and Survival: Is NIFTP Really a "Benign" Disease?

BACKGROUND: This study aimed to determine the incidence of noninvasive follicular thyroid neoplasm with papillary-like features (NIFTP) in Ontario, Canada and the predictors of disease-free survival (DFS) by comparing patients with follicular variant papillary thyroid cancer (FVPTC) and patients with NIFTP. METHODS: This population-based retrospective cohort study included all patients who had definitive surgery for well-differentiated thyroid cancer (WDTC) in Ontario, Canada between 1990 and 2001 and were followed until 2014. A conservative decision rule was applied to subtype-select FVPTCs into NIFTPs after pathology report review. The primary outcome was DFS, for which Cox proportional hazard regression analysis was performed to assess the impact of FVPTC versus NIFTP. RESULTS: At pathology re-review of the 725 FVPTC cases, 318 were reclassified as potential NIFTP. The median follow-up time was 15.3 years for the entire cohort and 15.9 years for those alive at the last follow-up visit. Disease failure occurred for 109 patients, 79 (19.4%) in the FVPTC group and 30 (9.4%) in the NIFTP group (p < 0.01). This effect was sustained in the multivariable analysis, with FVPTC showing significantly worse DFS than NIFTP (hazard ratio, 1.84; 95% confidence interval, 1.17-2.89). After recategorization of certain FVPTCs into NIFTPs, the findings showed that NIFTP accounted for 16.8% (1.461/8.699 per 100,000) of all WDTCs. CONCLUSION: The disease failure rate for NIFTP was 9.4%. The NIFTP diagnosis is challenging for the pathologist and may make tumor behavior difficult to predict for this entity. Caution should be used in the management of patients with an NIFTP.

Routine follow-up care after curative treatment of head and neck cancer: A survey of patients' needs and preferences for healthcare services.

OBJECTIVE: The experience of a cancer diagnosis and receiving treatment can have profound impacts on health and subsequently patients may require significant support. Often, these needs are not identified or addressed. Given that less is known about the follow-up requirements for head and neck cancer patients, this study aimed to describe their follow-up needs and preferences. METHODS: In Ontario, Canada from 2012-2014, 175 patients completed a questionnaire at an appointment one year after treatment. To identify associations between characteristics and follow-up needs, bivariate analyses and ordinal logistic regression models were employed. RESULTS: A diversity of follow-up requirements was found. The most commonly reported follow-up needs were having imaging tests performed (66%), receiving information on treatment side effects (84%) and prognosis details (95%). Many patients experienced an improvement in their health (79%) but notably, not all. Characteristics such as psychosocial and well-being measures (functional status, anxiety, fear of recurrence, quality of life), attitudes towards follow-up (reassurance, communication), demographics (age, sex, marital status), and stage of disease predicted needs and preferences for follow-up care (p < 0.05). CONCLUSION: While awaiting top-level evidence, this work demonstrates the variation in needs and supports the identification of patients with higher follow-up requirements by screening for well-being and enquiring about expectations in follow-up care.

Thyroid cancer incidence among Asian immigrants to Ontario, Canada: A population-based cohort study.

BACKGROUND: The highest rates of thyroid cancer are observed in Pacific Island nations as well as Australia and Asian countries bordering the Pacific. The objective of this study was to determine the risk for thyroid cancer among immigrants to Canada from Southeast and East Asia compared with immigrants from other regions and nonimmigrants. METHODS: This was a population-based, longitudinal cohort study using health care administrative data to examine all residents of Ontario without pre-existing thyroid cancer. Individuals were followed from January 1997 or 5 years after they became eligible for health care coverage in Ontario, whichever came later. Patients were followed until March 2015 for incident-differentiated thyroid cancer, and then for recurrence. RESULTS: The study followed 14,659,733 individuals for a median of 17 years. Thyroid cancer incidence was 43.8 cases per 100,000 person-years among Southeast Asian immigrants, 28.6 cases per 100,000 person-years among East Asian immigrants, 21.5 cases per 100,000 person-years among other immigrants, and 14.5 cases per 100,000 person-years among nonimmigrants. Incidence was highest among immigrants from the Philippines (52.7 cases per 100,000 person-years), South Korea (33.5 cases per 100,000 person-years), and China (30.0 cases per 100,000 person-years). Adjusted hazard ratios for thyroid cancer compared with nonimmigrants were 2.66 (95% confidence interval, 2.48-2.84) for Southeast Asian immigrants, 1.87 (95% confidence interval, 1.75-2.00) for East Asian immigrants, and 1.51 (95% confidence interval, 1.45-1.57) for other immigrants. Immigrants were more likely to have papillary histology and stage I cancer. East Asian immigrants, but not Southeast Asian immigrants, had a lower risk of recurrence (hazard ratio, 0.73 [95% confidence interval, 0.57-0.94] and 1.01 [95% confidence interval, 0.81-1.26], respectively). CONCLUSIONS: Immigrants from Southeast and East Asia had markedly higher thyroid cancer incidence than nonimmigrants. At particularly elevated risk were immigrants from the Philippines, South Korea, and China. Cancer 2017;123:3320-5. © 2017 American Cancer Society.

Did the addition of concurrent chemotherapy to conventional radiotherapy improve survival for patients with HPV+ve and HPV-ve Oropharynx cancer? A population-based study.

BACKGROUND: In the absence of clear evidence on the efficacy of concurrent chemoradiotherapy (CRT) over conventional radiotherapy (RT) for HPV+ve and for HPV-ve oropharyngeal cancer (OPC), this study compares the treatments and outcomes from pre-CRT years to post-CRT years. METHODS: A population-based retrospective treatment-effectiveness study based on all patients with OPC treated in Ontario Canada in 1998, 1999, 2003 and 2004. Charts were reviewed, tissue samples were requested and tissue was tested for p16 or in situ hybridisation. Overall survival (OS) and disease-specific survival (DSS) were compared by treatment era and by treatment type for all 1028 patients, for 865 treated for cure and for 610 with HPV status. RESULTS: There was no improvement in OS comparing pre-CRT to post-CRT eras for the HPV+ve patients (P=0.147) or for the HPV-ve patients (P=0.362). There was no difference in OS comparing CRT to RT for the HPV+ve cohort (HR=0.948 (0.642-1.400)) or for the HPV-ve patients (HR=1.083 (0.68-1.727)). CONCLUSIONS: In these 'real-world' patients what appeared to be improvements in OS with CRT in clinical trials were confounded by HPV status in Ontario. CRT did not improve outcomes for HPV+ve or for HPV-ve patients.

Increasing detection and increasing incidence in thyroid cancer.

BACKGROUND: It has been proposed that the increasing incidence of thyroid cancer is due to increasing detection. METHODS: Using administrative data, we compare by year from 1993 to 2006, the rates of diagnostic imaging tests of the neck (computed axial tomography--CT, magnetic resonance imaging--MRI, and non-obstetrical ultrasound--US) to the incidence of thyroid cancer for the population of the Province of Ontario Canada. RESULTS: Women and men have different rates of tests, and those rates reflect the rates of new diagnoses of thyroid cancer. CONCLUSIONS: The rising incidence of thyroid disease in women is associated with increasing numbers of diagnostic imaging tests.

Association of Tympanostomy Tubes With Future Risk of Advanced Ear Surgery-A Population Study.

OBJECTIVE: To investigate future surgery for chronic ear disease in children who underwent tympanostomy tube (TT) placement, compared with non-surgically treated patients and healthy controls. STUDY DESIGN: Retrospective population-based cohort study. SETTING: All hospitals in the Canadian province of Ontario. PATIENTS/INTERVENTION: Of children aged 18 years and younger, three cohorts were constructed: 1) TT: patients who had undergone at least one TT procedure (n = 193,880), 2) No-TT: patients with recurrent physician visits for middle ear concerns who did not undergo TT (n = 203,283), and 3) Control: an age-sex matched control group who had not had TT or physician visits for recurrent middle ear concerns (n = 961,168). MAIN OUTCOME MEASURES: Risk, and odds ratios (ORs) of surgery for chronic ear disease. RESULTS: The TT cohort had a higher risk of tympanoplasty (OR 9.50 versus No-TT, p < 0.001; OR 207.90 versus Control, p < 0.001), ossiculoplasty (OR 3.22 versus No-TT, p < 0.001; OR 84.13 versus Control, p < 0.001), atticotomy (OR 4.41 versus No-TT, p < 0.001; OR 44.78 versus Control, p < 0.001), and mastoidectomy (OR 3.22 versus No-TT, p < 0.001; OR 89.12 versus control, p < 0.001). CONCLUSION: This study describes the population risk of subsequent ear surgeries in TT patients. These TT patients have a significantly higher risk of surgery for chronic ear disease versus those patients with recurrent middle ear disease that did not undergo TT, and age-sex matched controls.

Explaining the Variation in Surgical Practice for Differentiated Thyroid Cancer in Ontario, Canada.

IMPORTANCE: In the management of differentiated thyroid cancer (DTC), the extent of surgical treatment required for most patients remains controversial and varies widely. This variation may be associated with the Enthusiasm Hypothesis, the notion that geographic differences in use of health care services are driven by the prevalence of physicians with a preference for particular services. OBJECTIVE: To evaluate the Enthusiasm Hypothesis and its applicability to the variation in the surgical treatment of thyroid cancer in Ontario, Canada. DESIGN, SETTING, AND PARTICIPANTS: This population-based study obtained electronic data on all health care-associated events for the complete population of insured residents of Ontario, Canada. Patients (n = 28 754) who were 18 years of age or older and underwent an initial therapeutic thyroid surgical procedure for a papillary or follicular carcinoma diagnosis between January 1, 2000, and December 31, 2015, were included. The final data analysis was performed January 31, 2019. EXPOSURES: Therapeutic thyroid cancer surgical procedure. MAIN OUTCOMES AND MEASURES: Numbers of surgeons, extent of surgical treatment, and case volumes in 14 geographic regions in Ontario. RESULTS: In total, 28 754 patients with DTC were included, of whom 22 600 (78.6%) were female, with a mean (SD) age of 49 (14) years. The use of total thyroidectomy for DTC varied widely across geographic regions of Ontario, from 45.8% to 77.1% of all cancer cases. More than 90% of the overall variation in practice (total thyroidectomy vs less-than-total thyroidectomy) could be explained by the practices of the high-volume surgeons (enthusiasts) in regions with the highest rates of thyroid cancer diagnosis. CONCLUSIONS AND RELEVANCE: The Enthusiasm Hypothesis appears to be consistent with the findings of this study. The practices of the high-volume surgeons who were enthusiastic for total thyroidectomy in the geographic regions with the highest rates of thyroid cancer diagnosis may account for the variation in practice across Ontario between 2000 and 2015.

The addition of chemotherapy to radiotherapy did not reduce the rate of distant metastases in low-risk HPV-related oropharyngeal cancer in a real-world setting.

BACKGROUND: Distant metastases (DM) are a leading cause of death for patients with oropharyngeal cancer (OPSCC). The objective of this study was to compare the rates of DM after chemoradiotherapy (CRT) and radiotherapy alone (RT) in patients with human papillomavirus (HPV)-positive and HPV-negative OPSCC. METHOD: In a retrospective population-based study of 525 patients across Ontario, Canada, in 1998/99/03/04, we compared treatment effectiveness using cumulative incidence function curves and cause-specific Cox regression models. RESULTS: Sixty of 525 patients developed DM. There was no difference in rates (overall 10%-15%) between HPV-positive and HPV-negative patients or between CRT- and RT-treated patients. CRT reduced the risk of DM for the 15% of all HPV-positive patients with higher risk (T4 and/or N3) and not for HPV-negative patients (hazard ratio, 1.82 [0.65-5.07]). CONCLUSION: The addition of platin-based chemotherapy to conventional RT did not decrease the rates of DM in the majority of patients with HPV-positive or in HPV-negative OPSSC.

Do doctors who order more routine medical tests diagnose more cancers? A population-based study from Ontario Canada.

BACKGROUND: The overuse of medical tests leads to higher costs, wasting of resources, and the potential for overdiagnosis of disease. This study was designed to determine whether the patients of family doctors who order more routine medical tests are diagnosed with more cancers. METHOD: A retrospective population-based cross-sectional study using administrative health care data in Ontario Canada. We investigated the ordering of 23 routine laboratories and imaging tests 2008-20012 by 6849 Ontario family physicians on their 4.9 million rostered adult patients. We compared physicians' test utilization and calculated case-mix adjusted observed to expected (O:E) utilization ratios to categorize physicians as Typical, Higher or Lower testers. Age-sex standardized rates (cases/10 000 patient years) and Rate Ratios were determined for cancers of the thyroid, prostate, breast, lymphoma, kidney, melanoma, uterus, ovary, lung, esophagus, and pancreas for each tester group. RESULTS: There was wide variation in the use of the 23 tests by Ontario physicians. 26% and 24% of physicians were deemed Higher Testers for laboratory and imaging tests, while 41% and 38% were Typical Testers. The patients of higher test users were diagnosed with more cancers of thyroid (laboratory [RR 1.61, 95% CI 1.39-1.87] and imaging [RR 2.08, 95% CI 0.88-2.30]) and prostate (laboratory [RR 1.10, 95% CI 1.03-1.18] and imaging [RR 1.05, 95% CI 1.00-1.10]). CONCLUSION: There is a wide variation in the ordering of routine and common medical tests among Ontario family doctors. The patients of higher testers were diagnosed with more thyroid and prostate cancers.

Evaluation of treatment outcomes in patients with supraglottic laryngeal cancer in Ontario, Canada: A population-based study.

BACKGROUND: Supraglottic laryngeal carcinoma has an entirely different etiology, clinical presentation, and prognosis compared to glottis cancer but the only evidence for the use of concurrent chemotherapy with radiotherapy (CRT) is the 5.4% 5-year improvement in overall survival (OS) for the combined laryngeal site. METHOD: We conducted a retrospective population-based study using administrative data to compare OS, disease-specific survival (DSS), laryngectomy-free survival, and laryngoesophageal dysfunction-free survival over time and by treatment for all patients with supraglottic laryngeal carcinoma diagnosed between January 1, 1990, and December 31, 2014, in Ontario, Canada. RESULTS: There was no improvement over time in OS (hazard ratio [HR] 1.006; P = .90), DSS (HR 1.031; P = .65), or laryngoesophageal dysfunction-free survival (P = .39). The patients selected for CRT had similar OS (HR 1.04; P = .66), laryngectomy-free survival (HR 0.95; P = .23), and laryngoesophageal dysfunction-free survival (P = .79) compared with patients undergoing radiotherapy. CONCLUSION: The addition of CRT by head and neck oncologists in Ontario, Canada, did not improve outcomes for the "real world" patients with supraglottic laryngeal carcinoma.

Rates and causes of 30-day readmission and emergency room utilization following head and neck surgery.

BACKGROUND: Unplanned returns to hospital are common, costly, and potentially avoidable. We aimed to investigate and characterize reasons for all-cause readmissions to hospital as in-patients (IPs) and visits to the Emergency Department (ED) within 30-days following patient discharge post head and neck surgery (HNS). METHODS: Retrospective case series with chart review. All patients within the Department of Otolaryngology - Head and Neck Surgery who underwent HNS for benign and malignant disease from January 1, 2010 to May 31, 2015 were identified. The electronic medical records of readmitted patients were reviewed for reasons of readmission, demographic data, and comorbidities. RESULTS: Following 1281 surgical cases, there were 41 (3.20%) IP readmissions and 109 (8.43%) ED visits within 30-days after discharge for HNS. For IP readmissions, most common causes included infection (26.8%), respiratory symptoms (17.1%), and pain (17.1%). Most common reasons for ED visits were for pain (31.5%), bleeding (17.6%), and infection (14.8%). Readmitted IPs had significantly higher health burden at pre-operative baseline as compared to patients who visited the ED when assessed with the American Society of Anesthesiology scores (p = 0.002) and the Cumulative Illness Rating Scale (p = 0.004). CONCLUSION: Rate of 30-day IP readmission and ED utilization was 3.20 and 8.43%, respectively. Pain and infection were common causes for returns to hospital. Discharge planning may be improved to target common causes for post-surgical hospital visits in order to decrease readmission rates.

Clinical predictors of multiple tympanostomy tube placements in Ontario children.

OBJECTIVES: To characterize risk factors that predict the need for multiple tympanostomy tube (TT) procedures. STUDY DESIGN: Retrospective population-based cohort study of children aged 18 years and younger in Ontario, Canada, who underwent at least one TT placement between January 1, 1994, and October 31, 2013. METHODS: The relative risk (RR) of need for multiple TT procedures was determined using log-binomial regression. RESULTS: There were 193,880 children who underwent TT insertion included in this cohort. Of these, 28.58% underwent at least two separate TT procedures. Over time, the RR of undergoing multiple TT procedures is decreasing for all children. In general, the younger the child was at the first TT procedure, the more likely the child was to undergo multiple TT procedures. Significantly higher RR for multiple TT procedures also was associated with male sex, the second-highest neighborhood income quintile, asthma or reactive airways, gastrointestinal disease, prematurity, or cleft lip and/or palate. Significantly lower RR for multiple TT procedures was associated with adenoidectomy or tonsillectomy (with or without adenoidectomy) at first TT placement or within 3 years prior. Furthermore, the benefit of adjuvant adenoidectomy or tonsillectomy was present for children aged under 4 years, in addition to those aged 4 years and older. CONCLUSION: Among Ontario children who have had TT placement, more than one in four will have multiple sets placed. These identified risk factors permit improved preoperative counseling and enable identification of children who need closer follow-up. LEVEL OF EVIDENCE: 2b. Laryngoscope, 128:991-997, 2018.

Audiometric Testing Guideline Adherence in Children Undergoing Tympanostomy Tubes: A Population-Based Study.

Objective Tympanostomy tube (TT) insertion is the most common ambulatory surgery performed on children. American Academy of Otolaryngology-Head and Neck Surgery Founda-tion (AAO-HNSF) Clinical Practice Guidelines (CPGs) recommend hearing testing for all pediatric TT candidates. The aim of this study was to assess audiometric testing in this population. Study Design Retrospective population-based cohort study. Setting All hospitals in the Canadian province of Ontario. Subjects and Methods All patients 12 years of age and younger who underwent at least 1 TT procedure between January 1993 and June 2016. The primary outcomes were the percentage of patients who underwent a hearing test within 1 year before and/or 1 year after surgery. Results A total of 316,599 bilateral TT procedures were performed during the study period (1993 to 2016). Presurgical hearing tests increased from 55.7% to 74.9%, and postsurgical hearing tests increased from 42.2% to 68.9%. Younger surgeons demonstrated a greater adherence to the CPGs (relative risk [RR], 1.22; 95% CI, 1.08-1.38; P = .001). Remarkably, there was not a spike in preoperative hearing tests following the introduction of the CPGs in 2013 (RR, 1.12; 95% CI, 0.85-1.47; P = .432). Presurgical hearing testing ranged from 26.1% to 83.5% across health regions. Conclusion In this cohort of children who underwent TT placement, the trends of preoperative and postoperative audiometric testing are increasing but are still lower than recommended by the CPGs, despite a tripling of practicing audiologists. This study describes the current state of testing in Ontario and highlights issues of access to audiology services, possible parent preferences, and the importance of ongoing continuing medical education for all health care practitioners.

Epidemiology and management of thoracic aortic dissections and thoracic aortic aneurysms in Ontario, Canada: A population-based study.

OBJECTIVES: To determine hospital incidence, mortality, and management for thoracic aortic dissections and aneurysms. METHODS: A population-based retrospective cohort study of anonymously linked data for residents of Ontario, Canada, was carried out. Incident cases of thoracic aortic dissections and aneurysms were identified between 2002 and 2014. Treatment and mortality trends were assessed. RESULTS: There were 5966 aortic dissections (Type A n = 2289 [38%] and Type B n = 3632 [61%]). Overall incidence proportion for aortic dissections was 4.6 per 100,000. There were 9392 thoracic aortic aneurysms with an overall incidence proportion of 7.6 per 100,000. The incidence for both dissections and aneurysms significantly increased over the 12-year study. Only 53% (1204 out of 2289) of Type A dissections underwent surgery. Type B dissection treatment was 83% (3000 out of 3632) medical, 10% (370 out of 3632) surgery, and 7% (262 out of 3632) endovascular. Thoracic aortic aneurysm treatment was 53% (4940 out of 9392) surgery, 44% (4129 out of 9392) medical, and 3% (323 out of 9392) endovascular. Thirty-five percent of known descending thoracic aortic aneurysms (323 out of 924) received a stent graft. Cardiac surgeons performed 87% of the open surgical repairs. Vascular surgeons performed 91% of the endovascular procedures. All-cause 3-year mortality significantly decreased for both aortic dissections (44% to 40%) and aneurysms (30% to 22%). All-cause hospital mortality also decreased. Women had worse outcomes than men. CONCLUSIONS: The incidence of thoracic aortic dissections and aneurysms increased over time but all-cause hospital and late outcomes improved. Gender differences exist. Men incur more disease but women have higher hospital mortality. Surgery was primarily referred to cardiac surgeons. Endovascular therapy was primarily referred to vascular surgeons.

Increased incidence of differentiated thyroid carcinoma and detection of subclinical disease.

BACKGROUND: Recent reports from North America and Europe have documented an annual increase in the incidence of differentiated thyroid carcinoma. We sought to investigate the relation between rates of detection, tumour size, age and sex. METHODS: Using the Ontario Cancer Registry, we identified 7422 cases of differentiated thyroid carcinoma diagnosed from Jan. 1, 1990, to Dec. 31, 2001. We obtained pathology reports for a random 10% of the 7422 patients for each year of the study period. The sample represented all Cancer Care Ontario regions. We compared the size of the patients' tumours by year, sex and age. RESULTS: As expected, the incidence of differentiated thyroid carcinoma increased over the 12-year period. A significantly higher number of small (< or = 2 cm), nonpalpable tumours were resected in 2001 than in 1990 (p = 0.001). The incidence of tumours 2-4 cm in diameter remained stable. When we examined differences in tumour detection rates by age and sex, we observed a disproportionate increase in the number of small tumours detected among women and among patients older than 45 years. INTERPRETATION: Our findings suggest that more frequent use of medical imaging has led to an increased detection rate of small, subclinical tumours, which in turn accounts for the higher incidence of differentiated thyroid carcinoma. This suggests that we need to re-evaluate our understanding of the trends in thyroid cancer incidence.

Do Lower-Risk Thyroid Cancer Patients Who Live in Regions with More Aggressive Treatments Have Better Outcomes?

BACKGROUND: The management of differentiated thyroid cancer has traditionally consisted of total thyroidectomy with or without adjuvant radioactive iodine. However, in the last two decades, this approach has been challenged, with the consideration of more conservative approaches such as less radical surgery and deferring adjuvant treatment, especially in lower-risk patients. The objective of this study was to consider the effectiveness of current treatment options by comparing the survival outcomes from different geographic regions with different treatment philosophies. This study design was based on the concept of natural experiments in patient care that occur when physicians in different regions treat the spectrum of typical patients with varying treatments. METHOD: This population-based retrospective cohort study investigated 2444 patients with differentiated thyroid cancer ≤4 cm between 1990 and 2001 from Ontario, Canada. Extent of disease and extent of surgery were abstracted from pathology reports and were linked to downstream administrative medical information on treatments and outcomes. Patient demographics, tumor characteristics, treatments, and outcomes were compared between those geographic regions with more aggressive treatments and those regions with less aggressive treatments. RESULTS: Treatment varied across the province. When comparing outcomes in regions where patients had more extensive treatment to those in regions where patients had less extensive therapy, similar rates were found for 15-year survival, recurrence, and survival after recurrence. CONCLUSION: There were significant variations in treatment but no differences in outcomes for regions with more versus less aggressive approaches. These findings support the trend toward more conservative management approaches in the treatment of thyroid cancer.

A user's guide to selecting a comorbidity index for clinical research.

You are creating a data abstraction form to assess the case mix, treatments, and treatment outcome for patients with cancer of the larynx at your center. You plan to perform univariate analysis including Kaplan-Meier curves with log-rank tests and multiple variable analysis to account for effect of disease and age on outcome. At your center some patients have radiotherapy, some have chemotherapy in association with radiotherapy, and some have primary surgery. A specific patient's treatment is based on the extent of disease and overall health. Patients with cancer of the larynx frequently have a variety of comorbid illnesses, often related to smoking and alcohol. For example, Mr. J.B. presented to the coronary care unit with his third myocardial infarction and was found to have a new cancer of the larynx. Due to his chronic obstructive pulmonary disease (COPD), diabetes, and past pulmonary embolus, he is not a candidate for either coronary revascularization or laryngectomy. How do you measure the impact of the comorbid illnesses on the decisions and the outcomes?

Interrater reliability of measurements of comorbid illness should be reported.

OBJECTIVE: Comorbidity indices are commonly used to stratify patients to control for treatment selection bias. The objectives here were to review the reporting of interrater reliability when studies use comorbidity indices in clinical research publications and to report the interrater reliability of four common indices in a particular research setting. STUDY DESIGN AND SETTING: Four trained abstractors reviewed the same 40 charts of patients with squamous cell carcinoma of the head and neck from a regional cancer center. Scores for the Charlson Index, the Index of Co-existent Disease, the Cumulative Illness Rating Scale, and the Kaplan-Feinstein Classification were calculated, and the intraclass correlation coefficient was used to assess interrater reliability. RESULTS: The details on the training of abstractors and the results of interrater reliability tests are not commonly reported. In our study setting, the Charlson Index had excellent reliability and the others had acceptable reliability. CONCLUSION: If the quality of a study using an index or scale is to be assessed, the reliability and interrater reliability of the score assignment process should be reported.