Comparative effectiveness of postoperative chemotherapy among older patients with non-metastatic rectal cancer treated with preoperative chemoradiotherapy

Effects of anticholinergic and sedative medication use on fractures: A self-controlled design study

BACKGROUND/OBJECTIVES

Unintentional falls are a leading cause of injury for older adults, and evidence is needed to understand modifiable risk factors. We evaluated 1-year fall-related fracture risk and whether dispensing of medications with anticholinergic/sedating properties is temporally associated with an increased odds of these fractures.

DESIGN

A retrospective cohort study with nested self-controlled analyses conducted between January 1, 2014, and December 31, 2016.

SETTING

Twenty percent nationwide, random sample of US Medicare beneficiaries.

PARTICIPANTS

New users of medications with anticholinergic/sedating properties who were 66+ years old and had Medicare Parts A, B, and D coverage but no claims for medications with anticholinergic/sedating properties in the year before initiation were eligible.

MEASUREMENTS

We followed new users of medications with anticholinergic/sedating properties until first non-vertebral, fall-related fracture (primary outcome), Medicare disenrollment, death, or end of study data. We estimated the 1-year risk with corresponding 95% confidence intervals (CIs) of first fracture after new use. We applied the self-controlled case-crossover and case-time-control designs to estimate odds ratios (ORs) and 95% CIs by comparing anticholinergic and/or sedating medication exposure (any vs. none) during a 14-day hazard period preceding the fracture to exposure to these medications during an earlier 14-day control period.

RESULTS

A total of 1,097,989 Medicare beneficiaries initiated medications with anticholinergic/sedating properties in the study period. The 1-year cumulative incidence of fall-related fracture, accounting for death as a competing risk, was 5.0% (95% CI: 5.0%-5.0%). Using the case-crossover design (n = 41,889), the adjusted OR for the association between anticholinergic/sedating medications and fractures was 1.03 (95% CI: 0.99, 1.08). Accounting for the noted temporal trend using the case-time-control design (n = 209,395), the adjusted OR was 1.60 (95% CI: 1.52, 1.69).

CONCLUSION

Use of anticholinergic/sedating medication was temporally associated with an increased odds of fall-related fractures. Patients and their healthcare providers should consider pharmacologic and non-pharmacologic treatments for the target condition that are safer.

Effectiveness of adjuvant FOLFOX vs 5FU/LV in adults over age 65 with stage II and III colon cancer using a novel hybrid approach

PURPOSE

Estimates of cancer therapy effects can differ in clinical trials and clinical practice, partly due to underrepresentation of certain patient subgroups in trials. We utilize a hybrid approach, combining clinical trial and real-world data, to estimate the comparative effectiveness of two adjuvant chemotherapy regimens for colon cancer.

METHODS

We identified patients aged 66 and older enrolled in the Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer. Similar patients were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, initiating adjuvant chemotherapy with either 5-fluorouracil (5FU) alone or in combination with oxaliplatin (FOLFOX). We used logistic regression to estimate the likelihood of trial enrollment as a function of age, sex, and substage. Using inverse odds of sampling weights (IOSW), we compared 5-year mortality in patients randomized to FOLFOX vs 5FU using weighted Cox proportional hazards regression, the Nelson-Aalen estimator for cumulative hazards, and bootstrapping for 95% confidence intervals (CIs).

RESULTS

There were 690 trial participants and 3834 SEER-Medicare patients. The SEER-Medicare population was older and had a higher proportion of stage IIIB and IIIC patients than the trial. After controlling for differences between populations, the IOSW 5-year HR was 1.21 (0.89, 1.65), slightly farther from the null than the trial estimate (HR = 1.14, 95%CI: 0.87, 1.49).

CONCLUSIONS

This study supports mounting evidence of little to no incremental reduction in 5-year mortality for FOLFOX vs 5FU in older adults with stage II-III colon cancer, emphasizing the importance of combining clinical trial and real-world data to support such conclusions.

Comparison of Medicare Claims-based Proxy Measures of Poor Function and Associations With Treatment Receipt and Mortality in Older Colon Cancer Patients

BACKGROUND

Multiple claims-based proxy measures of poor function have been developed to address confounding in observational studies of drug effects in older adults. We evaluated agreement between these measures and their associations with treatment receipt and mortality in a cohort of older colon cancer patients.

METHODS

Medicare beneficiaries age 66+ diagnosed with stage II-III colon cancer were identified in the Surveillance, Epidemiology, and End Results-Medicare database (2004-2011). Poor function was operationalized by: (1) summing the total poor function indicators for each model; and (2) estimating predicted probabilities of poor function at diagnosis. Agreement was evaluated using Fleiss' κ and Spearman's correlation. Associations between proxy measures and: (1) laparoscopic versus open surgery; (2) chemotherapy versus none; (3) 5-fluorouracil (5FU)+oxaliplatin (FOLFOX) versus 5FU monotherapy; and (4) 1-year mortality were estimated using log-binomial regression, controlling for age, sex, stage, and comorbidity. Survival estimates were stratified by functional group, age, and comorbidity.

RESULTS

Among 29,687 eligible colon cancer patients, 67% were 75+ years and 45% had stage III disease. Concordance across the poor function indicator counts was moderate (κ: 0.64) and correlation of predicted probability measures varied (ρ: 0.21-0.74). Worse function was associated with lower chemotherapy and FOLFOX receipt, and higher 1-year mortality. Within age and comorbidity strata, poor function remained associated with mortality.

CONCLUSIONS

While agreement varied across the claims-based proxy measures, each demonstrated anticipated associations with treatment receipt and mortality independent of comorbidity. Claims-based comparative effectiveness studies in older populations should consider applying one of these models to improve confounding control.

The importance and implications of comparator selection in pharmacoepidemiologic research

PURPOSE OF REVIEW

Pharmacoepidemiologic studies employing large databases are critical to evaluating the effectiveness and safety of drug exposures in large and diverse populations. Because treatment is not randomized, researchers must select a relevant comparison group for the treatment of interest. The comparator group can consist of individuals initiating: (1) a similarly indicated treatment (active comparator), (2) a treatment used for a different indication (inactive comparator) or (3) no particular treatment (non-initiators). Herein we review recent literature and describe considerations and implications of comparator selection in pharmacoepidemiologic studies.

RECENT FINDINGS

Comparator selection depends on the scientific question and feasibility constraints. Because pharmacoepidemiologic studies rely on the choice to initiate or not initiate a specific treatment, rather than randomization, they are at-risk for confounding related to the comparator choice including: by indication, disease severity and frailty. We describe forms of confounding specific to pharmacoepidemiologic studies and discuss each comparator along with informative examples and a case study. We provide commentary on potential issues relevant to comparator selection in each study, highlighting the importance of understanding the population in whom the treatment is given and how patient characteristics are associated with the outcome.

SUMMARY

Advanced statistical techniques may be insufficient for reducing confounding in observational studies. Evaluating the extent to which comparator selection may mitigate or induce systematic bias is a critical component of pharmacoepidemiologic studies.

Management of locally advanced rectal cancer in the elderly: a critical review and algorithm

Colorectal cancer incidence and death rates have been declining over the past 10 years. However, it remains the second leading cause of death in men ages 60-79 and the third leading cause of death in men over 80 and in women over 60 years old. However, there is little data specific to the treatment of the elder patient, since few of these patients are included in trials. With the advent of improved therapies, there are many alternative options available. Still, no definitive consensus or guidelines have been defined for this particular patient population. The goal of this study is to review the literature on the management of rectal cancer in the elderly and to propose treatment algorithms to help the oncology team in treatment decision-making.

Decision-Making Strategy for Rectal Cancer Management Using Radiation Therapy for Elderly or Comorbid Patients

Rectal cancer predominantly affects patients older than 70 years, with peak incidence at age 80 to 85 years. However, the standard treatment paradigm for rectal cancer oftentimes cannot be feasibly applied to these patients owing to frailty or comorbid conditions. There are currently little information and no treatment guidelines to help direct therapy for patients who are elderly and/or have significant comorbidities, because most are not included or specifically studied in clinical trials. More recently various alternative treatment options have been brought to light that may potentially be utilized in this group of patients. This critical review examines the available literature on alternative therapies for rectal cancer and proposes a treatment algorithm to help guide clinicians in treatment decision making for elderly and comorbid patients.

Feasibility of Representing Data from Published Nursing Research Using the OMOP Common Data Model

We explored the feasibility of representing nursing research data with the Observational Medical Outcomes Partners (OMOP) Common Data Model (CDM) to understand the challenges and opportunities in representing various types of health data not limited to diseases and drug treatments. We collected 1,431 unique data items from 256 nursing articles and mapped them to the OMOP CDM. A deeper level of mapping was explored by simulating 10 data search use cases. Although the majority of the data could be represented in the OMOP CDM, potential information loss was identified in contents related to patient reported outcomes, socio-economic information, and locally developed nursing intervention protocols. These areas will be further investigated in a follow up study. We will use lessons learned in this study to inform the metadata development efforts for data discovery.