Lingsong Yun

Rates and risk factors for prolonged opioid use after major surgery: population based cohort study

Objective To describe rates and risk factors for prolonged postoperative use of opioids in patients who had not previously used opioids and undergoing major elective surgery. Design Population based retrospective cohort study. Setting Acute care hospitals in Ontario, Canada, between 1 April 2003 and 31 March 2010. Participants 39 140 opioid naïve patients aged 66 years or older who had major elective surgery, including cardiac, intrathoracic, intra-abdominal, and pelvic procedures. Main outcome measure Prolonged opioid use after discharge, as defined by ongoing outpatient prescriptions for opioids for more than 90 days after surgery. Results Of the 39 140 patients in the entire cohort, 49.2% (n=19 256) were discharged from hospital with an opioid prescription, and 3.1% (n=1229) continued to receive opioids for more than 90 days after surgery. Following risk adjustment with multivariable logistic regression modelling, patient related factors associated with significantly higher risks of prolonged opioid use included younger age, lower household income, specific comorbidities (diabetes, heart failure, pulmonary disease), and use of specific drugs preoperatively (benzodiazepines, selective serotonin reuptake inhibitors, angiotensin converting enzyme inhibitors). The type of surgical procedure was also highly associated with prolonged opioid use. Compared with open radical prostatectomies, both open and minimally invasive thoracic procedures were associated with significantly higher risks (odds ratio 2.58, 95% confidence interval 2.03 to 3.28 and 1.95 1.36 to 2.78, respectively). Conversely, open and minimally invasive major gynaecological procedures were associated with significantly lower risks (0.73, 0.55 to 0.98 and 0.45, 0.33 to 0.62, respectively). Conclusions Approximately 3% of previously opioid naïve patients continued to use opioids for more than 90 days after major elective surgery. Specific patient and surgical characteristics were associated with the development of prolonged postoperative use of opioids. Our findings can help better inform understanding about the long term risks of opioid treatment for acute postoperative pain and define patient subgroups that warrant interventions to prevent progression to prolonged postoperative opioid use.

Risk of Elective Major Noncardiac Surgery After Coronary Stent Insertion A Population-Based Study

Background— Guidelines recommend that noncardiac surgery be delayed until 30 to 45 days after bare-metal stent implantation and 1 year after drug-eluting stent implantation. Methods and Results— We used linked registry data and population-based administrative health care databases to conduct a cohort study of 8116 patients (≥40 years of age) who underwent major elective noncardiac surgery in Ontario, Canada between 2003 and 2009, and received coronary stents within 10 years before surgery. Approximately 34% (n=2725) underwent stent insertion within 2 years before surgery, of whom 905 (33%) received drug-eluting stents. For comparison, we assembled a separate cohort of 341 350 surgical patients who had not undergone coronary revascularization. The primary outcome was 30-day major adverse cardiac events (mortality, readmission for acute coronary syndrome, or repeat coronary revascularization). The overall rate of 30-day events in patients with coronary stents was 2.1% (n=170). When the interval between stent insertion and surgery was <45 days, event rates were high for bare-metal (6.7%) and drug-eluting (20.0%) stents. When the interval was 45 to 180 days, the event rate for bare-metal stents was 2.6%, approaching that of intermediate-risk nonrevascularized individuals. Adjusted analyses suggested that event rates were increased if this interval exceeded 180 days. For drug-eluting stents, the event rate was 1.2% once the interval exceeded 180 days, approaching that of intermediate-risk nonrevascularized individuals. Conclusions— The earliest optimal time for elective surgery is 46 to 180 days after bare-metal stent implantation or >180 days after drug-eluting stent implantation.

Diuretic dose and long-term outcomes in elderly patients with heart failure after hospitalization

BACKGROUND The array of outcomes according to longitudinal furosemide doses in heart failure (HF) have not been evaluated. We examined the relationship of dynamic furosemide dose with mortality and hospitalizations for cardiovascular disease and renal dysfunction. METHODS Among elderly patients with HF (>or=65 years) newly discharged from hospital, dynamic furosemide exposure was determined by examining dose fluctuations up to 5 years of follow-up using the Ontario Drug Benefit pharmacare database. Dynamic furosemide exposures were classified as low dose (LD; 1-59 mg/d), medium dose (MD; 60-119 mg/d), or high dose (HD; >or=120 mg/d). Outcomes were assessed by modeling furosemide exposure as a time-dependent covariate. RESULTS Among 4,406 patients (78.4 +/- 7.0 years; 50.5% male), 46% changed furosemide dose categories within 1 year, and 63% changed dose categories over the follow-up period. High-dose furosemide patients were younger, were mostly male, and exhibited more ischemic or valvular disease, diabetes, atrial fibrillation, hypotension, hyponatremia, and higher baseline creatinine than LD. Compared with LD, MD exposure was associated with increased mortality with adjusted hazard ratio 1.96 (95% CI 1.79-2.15), whereas HD exposure conferred greater mortality risk with hazard ratio 3.00 (95% CI 2.72-3.31) after multiple covariate adjustment (both P < .001). Adjusted risks of hospitalization for HF (MD: 1.24 [95% CI 1.12-1.38] and HD: 1.43 [95% CI 1.26-1.63]), renal dysfunction (MD: 1.56 [95% CI 1.38-1.76] and HD: 2.16 [95% CI 1.88-2.49]), and arrhythmias (MD: 1.15 [95% CI 1.03-1.30] and HD: 1.45 [95% CI 1.27-1.66]) were also higher with increasing furosemide exposure. CONCLUSION Exposure to higher furosemide doses is associated with worsened outcomes and is broadly predictive of death and morbidity.

Incidence, Predictors, and Prognostic Implications of Hospitalization for Late Bleeding After Percutaneous Coronary Intervention for Patients Older Than 65 Years

Background—Previous data on bleeding after percutaneous coronary intervention (PCI) have been obtained primarily from randomized trials that focused on in-hospital bleeding. The incidence of late bleeding after PCI, its independent predictors, and its prognostic importance in clinical practice has not been fully addressed. Methods and Results—We evaluated 22 798 patients aged >65 years who underwent PCI from December 1, 2003, to March 31, 2007, in Ontario, Canada. Cox proportional hazard models were used to determine factors associated with late bleeding, which was defined as hospitalization for bleeding after discharge from the index PCI, and to estimate risk of death or myocardial infarction associated with late bleeding. We found that 2.5% of patients were hospitalized for bleeding in the year after PCI, with 56% of bleeding episodes due to gastrointestinal bleed. The most significant predictor of late bleeding was warfarin use after PCI (hazard ratio [HR], 3.12). Other significant predictors included age (HR, 1.41 per 10 years), male sex (HR, 1.24), cancer (HR, 1.80), previous bleeding (HR, 2.42), chronic kidney disease (HR, 1.93), and nonsteroidal antiinflammatory drug use (HR, 1.73). After adjusting for baseline covariates, hospitalization for a bleeding episode was associated with a significantly increased 1-year hazard of death or myocardial infarction (HR, 2.39; 95% CI, 1.93 to 2.97) and death (HR, 3.38; 95% CI, 2.60 to 4.40). Conclusions—Hospitalization for late bleeding after PCI is associated with substantially increased risk of death and myocardial infarction. The use of triple therapy (ie, aspirin, thienopyridine, and warfarin) is associated with the highest risk of late bleeding.

A population-based description of atrial fibrillation in the emergency department, 2002 to 2010.

STUDY OBJECTIVE We aimed to describe the demographics, care, and outcomes of patients with atrial fibrillation in the emergency department (ED), as well as temporal changes over time. METHODS In this retrospective cohort study, we used a province-wide database to identify all adult patients who were treated in a nonpediatric ED in the province of Ontario with a primary diagnosis of atrial fibrillation, April 2002 to March 2010. We determined the frequency and rate of ED visits and assessed patient demographics, ED care, and outcomes, both overall and by year. RESULTS During the 8-year study period, 113,786 patients made 143,003 ED visits for atrial fibrillation, accounting for 0.5% of all ED visits. The annual number of ED visits increased from 15,931 to 20,168 (29.4%; 95% confidence interval [CI] 28.7% to 30.1%) between 2002 and 2010, whereas the crude rate increased from 172 per 100,000 to 195 per 100,000 persons. Median age was 72.0 years (Interquartile range 61.0 to 80.0 years) and 50.8% were women, which did not change significantly during the study period. The percentage of index ED visits with a physician billing for cardioversion increased from 6.3% (95% CI 5.9% to 6.7%) to 11.8% (95% CI 11.3% to 12.3%). Although the percentage of patients with a CHADS2 score greater than or equal to 2 increased from 49.3% (95% CI 48.4% to 50.2%) to 53.6% (95% CI 52.9% to 54.4%) and high-acuity ED triage scores increased from 41.1% (95% CI 40.2% to 42.0%) to 62.5% (95% CI 61.7% to 63.2%), hospital admissions decreased from 48.1% (95% CI 47.3% to 49.0%) to 38.4% (95% CI 37.6% to 39.2%). Thirty-day mortality was 3.3% (95% CI 3.2% to 3.4%) and showed a slight downward trend during the study period (P=.05), whereas subsequent hospitalizations within 30 days for atrial fibrillation or stroke (2.8%; 95% CI 2.7% to 2.9%) and repeated ED visits (7.3%; 95% CI 7.1% to 7.4%) remained unchanged. CONCLUSION The number of ED visits for atrial fibrillation increased markedly during an 8-year period. Although it appears that slightly higher-risk patients are being treated in the provinces EDs, fewer patients are being admitted to the hospital, and mortality rates have not increased.

Screening for osteoporosis in men receiving androgen deprivation therapy.

To the Editor: Prostate cancer is the most common cancer in men. One in 2 men with prostate cancer is expected to receive androgen deprivation therapy (ADT). Use of ADT is associated with accelerated bone loss and an increased risk of fractures. To better characterize fracture risk and optimize bone health, a bone mineral density (BMD) test has been recommended prior to ADT initiation since 2006 in Canada and elsewhere. Low rates of BMD use have been reported by single centers. We examined the rate of BMD testing in men starting ADT in the province of Ontario, Canada, between 1995 and 2008. Methods. We identified men aged 66 years or older who were starting ADT for prostate cancer, using linked administrative databases at the Institute for Clinical Evaluative Sciences in Ontario, Canada (population approximately 11 million) and the Ontario Cancer Registry as previously described. These databases have been shown to be 85% to 99% complete and accurate. Men diagnosed between January 1, 1995, and December 31, 2008, and receiving at least 6 months of continuous medical ADT (luteinizing–hormone-releasing hormone agonists, antiandrogens, or both) or undergoing orchiectomy were included. The BMD tests used dual x-ray absorptiometry within 2 years of starting ADT and were captured using outpatient claims. Sociodemographic characteristics, comorbidity information (including prior diagnoses of osteoporosis and fragility fractures, ie, hip, spine, or wrist), and prior bisphosphonate use were obtained from inpatient and outpatient records using specific diagnostic, procedure, and claims codes as previously described. We examined whether a BMD test was performed over time using counts (per 100 person-years) and multivariable logistic regression using SAS version 9.2 (SAS Institute Inc). Level of significancewasa P valueof less than .05andstatistical tests were2-sided.Studyapprovalwasobtainedfromtheinstitutional research ethics board; individual patient consent was waived. Results. We identified 33 036 men (mean age: 76.0 years; range: 66-100 years) with prostate cancer who initiated ADT during the study period. A prior BMD test was performed in 1591 men (4.8%), 1332 (4.0%) had a prior diagnosis of osteoporosis, 1053 (3.2%) had a prior fragility fracture, and 808 (2.4%) were taking bisphosphonates at baseline. The use of BMD tests within 2 years of starting ADT ranged from 0.5 per 100 person-years in 1995 to 18.0 per 100 personyears in 2008 (FIGURE). Even among ADT users at high risk of osteoporosis (prior fragility fractures) or fractures (prior diagnosis of osteoporosis), BMD test ordering remained low, never reaching 50% of patients (Figure). Predictors of greater BMD testing included younger age, not living in a rural area, later start year of ADT, prior osteoporosis, prior BMD test, prior bisphosphonate use, and having a regular primary care physician (all P .01) (TABLE).

Association between tamoxifen treatment and diabetes: a population-based study.

There is increasing evidence linking breast cancer and diabetes; however, few studies have explored the association between cancer treatments and risk of diabetes. Tamoxifen may increase diabetes incidence through its estrogen‐inhibiting effects. This study assessed whether tamoxifen treatment in older breast cancer survivors is associated with an increased risk of diabetes.

A Population-based Analysis of Outpatient Colonoscopy in Adults Assisted by an Anesthesiologist

Background:The use of propofol to sedate patients for colonoscopy, generally administered by an anesthesiologist in North America, is increasingly popular. In the United States, regional use of anesthesiologist-assisted endoscopy appears to correlate with local payor policy. This study’s objective was to identify nonpayor factors (patient, physician, institution) associated with anesthesiologist assistance at colonoscopy. Methods:The authors performed a population-based cross-sectional analysis using Ontario health administrative data, 1993–2005. All outpatient colonoscopies performed on adults were identified. Hierarchical multivariable modeling was used to identify patient (age, sex, income quintile, comorbidity), physician (specialty, colonoscopy volume), and institution (type, volume) factors associated with receipt of anesthesiologist-assisted colonoscopy. Results:During the study period, 1,838,879 colonoscopies were performed on 1,202,548 patients. The proportion of anesthesiologist-assisted colonoscopies rose from 8.4% in 1993 to 19.1% in 2005 (P < 0.0001). In the hierarchical model, patients in low-volume community hospitals were five times more likely to receive anesthesiologist-assisted colonoscopy than patients in high-volume community hospitals (odds ration 4.9; 95% confidence interval 4.4–5.5). Less than 1% of colonoscopies in academic hospitals were anesthesiologist-assisted. Compared to gastroenterologists, surgeons were more likely to perform anesthesiologist-associated colonoscopy (odds ratio 1.7; 95% confidence interval 1.1–2.6). Conclusions:In Ontario, rates of anesthesiologist-assisted colonoscopy have risen dramatically. Institution type was most strongly associated with this practice. Further investigation is needed to determine the most appropriate criteria for the use of anesthesiology services during colonoscopy.

Duration of Preoperative β-Blockade and Outcomes After Major Elective Noncardiac Surgery

BACKGROUND Although practice guidelines recommend that perioperative β-blockade be initiated at least several days to weeks before noncardiac surgery is performed, the minimum required period of preoperative therapy is unclear. METHODS Population-based administrative databases were used to conduct a cohort study of 48,103 patients aged ≥ 66 years who underwent major elective noncardiac surgery in Ontario, Canada and received preoperative β-blocker therapy. We used multivariable logistic regression to determine the association of duration of preoperative β-blocker treatment (classified as 1-7 days, 8-30 days, and ≥ 31 days) with 30-day mortality, 30-day myocardial infarction (MI), 30-day ischemic stroke, and 1-year mortality. RESULTS The duration of preoperative β-blocker treatment was 1-7 days in 1105 patients (2.3%), 8-30 days in 2639 patients (5.5%), and ≥ 31 days in 44,269 patients (92.0%). Compared with ≥ 31 days of preoperative therapy, 1-7 days of therapy was associated with increased 30-day mortality (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.03-2.16; P = 0.03], whereas 8-30 days of therapy was not (OR, 0.95; 95% CI, 0.69-1.31; P = 0.77). One to 7 days of preoperative therapy was not significantly associated with 1-year mortality (OR, 1.06; 95% CI, 0.84-1.35; P = 0.62), 30-day MI (OR, 1.26; 95% CI, 0.92-1.71; P = 0.15), or 30-day ischemic stroke (OR, 1.37; 95% CI, 0.64-2.94; P = 0.41). CONCLUSIONS Initiation of β-blocker therapy 1-7 days before noncardiac surgery is associated with increased 30-day mortality. The findings merit further evaluation by randomized trials.

Population-based assessment of emergency room visits and hospitalizations among women receiving adjuvant chemotherapy for early breast cancer.

PURPOSE Adjuvant chemotherapy is considered standard care for patients with lymph node (LN) -positive and high-risk LN-negative early breast cancer (EBC). Although chemotherapy-associated toxicities are documented in clinical trials, the impact of toxicities on emergency room (ER) visits and hospitalizations (ER + Hs) at a population level with contemporary chemotherapy is unknown. We undertook a population-based study of ER + Hs in patients with EBC receiving adjuvant chemotherapy compared with noncancer controls (NCCs). METHODS All patients diagnosed with EBC between January 2007 and December 2009 in Ontario, Canada, were identified from the Ontario Cancer Registry. Patient records were linked deterministically to provincial health care databases to provide comprehensive medical follow-up. All patients received ≥ one cycle of adjuvant chemotherapy. Patient cases of EBC (n = 8,359) were matched to NCCs (n = 8,359) on age, comorbidity, and geographic location. ER + Hs within 30 days of chemotherapy were identified. If the primary reason for the visit was a common chemotherapy toxicity, the visit was considered chemotherapy associated. All-cause and chemotherapy-associated visits were compared between patient cases and controls. Logistic regression models were used to identify covariates associated with ER + Hs. RESULTS The proportion of patients with at least one ER + H was significantly higher in patients with EBC undergoing chemotherapy compared with NCCs (43.4% v 9.4%; P < .001). Patients with EBC were also more likely to have multiple ER + Hs (17.9% v 2.4%; P < .001). On multivariable analysis, comorbidity, receiving a regimen containing docetaxel, and certain geographic regions were associated with increased odds of ER + Hs. CONCLUSION ER + Hs are common among patients with EBC receiving chemotherapy and significantly higher than among controls. This represents a potential opportunity for quality improvement.