Falling Down on the Job: Evaluation and Treatment of Fall Risk Among Older Adults With Upper Extremity Fragility Fractures

BACKGROUND

Clinical practice guidelines recommend fall risk assessment and intervention for older adults who sustain a fall-related injury to prevent future injury and mobility decline.

OBJECTIVE

The aim of this study was to describe how often Medicare beneficiaries with upper extremity fracture receive evaluation and treatment for fall risk.

DESIGN

Observational cohort.

METHODS

Participants were fee-for-service beneficiaries age 66 to 99 treated as outpatients for proximal humerus or distal radius/ulna ("wrist") fragility fractures. -Participants were studied using Carrier and Outpatient Hospital files. The proportion of patients evaluated or treated for fall risk up to 6 months after proximal humerus or wrist fracture from 2007-2009 was examined based on evaluation, treatment, and diagnosis codes. Time to evaluation and number of treatment sessions were calculated. Logistic regression was used to analyze patient characteristics that predicted receiving evaluation or treatment. Narrow (gait training) and broad (gait training or therapeutic exercise) definitions of service were used.

RESULTS

There were 309,947 beneficiaries who sustained proximal humerus (32%) or wrist fracture (68%); 10.7% received evaluation or treatment for fall risk or gait issues (humerus: 14.2%; wrist: 9.0%). Using the broader definition, the percentage increased to 18.5% (humerus: 23.4%; wrist: 16.3%). Factors associated with higher likelihood of services after fracture were: evaluation or treatment for falls or gait prior to fracture, more comorbidities, prior nursing home stay, older age, humerus fracture (vs wrist), female sex, and white race.

LIMITATIONS

Claims analysis may underestimate physician and physical therapist fall assessments, but it is not likely to qualitatively change the results.

CONCLUSIONS

A small proportion of older adults with upper extremity fracture received fall risk assessment and treatment. Providers and health systems must advance efforts to provide timely evidence-based management of fall risk in this population.

Medical home transformation and breast cancer screening

OBJECTIVES

The patient-centered medical home (PCMH) continues to gain momentum as a primary care delivery system. We evaluated whether medical home transformation of primary care practices is associated with the use of breast cancer screening, a broadly endorsed preventive service.

STUDY DESIGN

Retrospective cohort study evaluating 12 Brigham and Women's Hospital (BWH)-affiliated primary care clinics in greater Boston, Massachusetts.

METHODS

Practice transformation was measured quarterly using a continuous PCMH transformation score (range = 0-100) modeled after National Committee for Quality Assurance recognition requirements. We included women aged 50 to 74 years who had at least 1 primary care visit at a participating clinic between April 2012 and December 2013 (n = 20,349)-a period of medical home transformation. The main measures included: a) whether screening was up-to-date at the time of the visit (mammography completion within 24 months prior to the visit); and b) if screening was overdue at the visit (ie, it had been more than 24 months since the last mammogram), and whether timely screening was completed within 3 months after the visit.

RESULTS

In adjusted analyses, PCMH transformation scores were negatively associated with up-to-date screening status (odds ratio [OR] for a 20-point change, 0.93; 95% confidence interval [CI], 0.89-0.96) and with timely screening of women who were overdue (OR, 0.94; 95% CI, 0.87-1.02).

CONCLUSIONS

Preventative care, such as breast cancer screening, may not improve in early PCMH implementation.

Patterns of Prescription Drug Use Before and After Fragility Fracture

IMPORTANCE

Patients who have a fragility fracture are at high risk for subsequent fractures. Prescription drugs represent 1 factor that could be modified to reduce the risk of subsequent fracture.

OBJECTIVE

To describe the use of prescription drugs associated with fracture risk before and after fragility fracture.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study conducted between February 2015 and March 2016 using a 40% random sample of Medicare beneficiaries from 2007 through 2011 in general communities throughout the United States. A total of 168 133 community-dwelling Medicare beneficiaries who survived a fracture of the hip, shoulder, or wrist were included. Cohort members were required to be enrolled in fee-for-service Medicare with drug coverage (Parts A, B, and D) and to be community dwelling for at least 30 days in the immediate 4-month postfracture period.

EXPOSURES

Prescription drug use during the 4-month period before and after a fragility fracture.

MAIN OUTCOMES AND MEASURES

Prescription fills for drug classes associated with increased fracture risk were measured using Part D retail pharmacy claims. These were divided into 3 categories: drugs that increase fall risk; drugs that decrease bone density; and drugs with unclear fracture risk mechanism. Drugs that increase bone density were also tracked.

RESULTS

A total of 168 133 patients with a fragility fracture (141 569 women; 84.2%) met the inclusion criteria for this study; 91.8% were white. Across all fracture types, the mean (SD) age was 80.0 (7.7) years, and 53.2% of the fracture cohort was hospitalized at the time of the index fracture, although this varied significantly depending on fracture type (100% of hip fractures, 8.2% of wrist fractures, and 15.0% of shoulder fractures). The frequency of discharge to an institution for rehabilitation following hospitalization also varied by fracture type, but the mean (SD) duration of acute rehabilitation did not: 28.1 (19.8) days. Most patients were exposed to at least 1 nonopiate drug associated with increased fracture risk in the 4 months before fracture (77.1% of hip, 74.1% of wrist, and 75.9% of shoulder fractures). Approximately 7% of these patients discontinued this drug exposure after the fracture, but this was offset by new users after fracture. Consequently, the proportion of the cohort exposed following fracture was unchanged (80.5%, 74.3%, and 76.9% for hip, wrist, and shoulder, respectively). There was no change in the average number of fracture-associated drugs used. This same pattern of use before and after fracture was observed across all 3 drug mechanism categories. Use of drugs to strengthen bone density was uncommon (≤25%) both before and after fracture.

CONCLUSIONS AND RELEVANCE

Exposure to prescription drugs associated with fracture risk is infrequently reduced following fragility fracture occurrence. While some patients eliminate their exposure to drugs associated with fracture, an equal number initiate new high-risk drugs. This pattern suggests there is a missed opportunity to modify at least one factor contributing to secondary fractures.

Second fractures among older adults in the year following hip, shoulder, or wrist fracture

We report on second fracture occurrence in the year following a hip, shoulder or wrist fracture using insurance claims. Among 273,330 people, 4.3 % had a second fracture; risk did not differ by first fracture type. Estimated adjusted second fracture probabilities may facilitate population-based evaluation of secondary fracture prevention strategies.

INTRODUCTION

The purpose of this study was estimate second fracture risk for the older US population in the year following a hip, shoulder, or wrist fracture.

METHODS

Observational cohort study of Medicare fee-for-service beneficiaries with an index hip, shoulder, or wrist fragility fracture in 2009. Time-to-event analyses using Cox proportional hazards models to characterize the relationship between index fracture type (hip, shoulder, wrist) and patient factors (age, gender, and comorbidity) on second fracture risk in the year following the index fracture.

RESULTS

Among 273,330 individuals with fracture, 11,885 (4.3 %) sustained a second hip, shoulder or wrist fracture within one year. Hip fracture was most common, regardless of the index fracture type. Comparing adjusted second fracture risks across index fracture types reveals that the magnitude of second fracture risk within each age-comorbidity group is similar regardless of the index fracture. Men and women face similar risks with frequently overlapping confidence intervals, except among women aged 85 years or older who are at greater risk.

CONCLUSIONS

Regardless of index fracture type, second fractures are common in the year following hip, shoulder or wrist fracture. Secondary fracture prevention strategies that take a population perspective should be informed by these estimates which take competing mortality risks into account.

Evaluation of an Automated Information Extraction Tool for Imaging Data Elements to Populate a Breast Cancer Screening Registry

Breast cancer screening is central to early breast cancer detection. Identifying and monitoring process measures for screening is a focus of the National Cancer Institute's Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) initiative, which requires participating centers to report structured data across the cancer screening continuum. We evaluate the accuracy of automated information extraction of imaging findings from radiology reports, which are available as unstructured text. We present prevalence estimates of imaging findings for breast imaging received by women who obtained care in a primary care network participating in PROSPR (n = 139,953 radiology reports) and compared automatically extracted data elements to a "gold standard" based on manual review for a validation sample of 941 randomly selected radiology reports, including mammograms, digital breast tomosynthesis, ultrasound, and magnetic resonance imaging (MRI). The prevalence of imaging findings vary by data element and modality (e.g., suspicious calcification noted in 2.6% of screening mammograms, 12.1% of diagnostic mammograms, and 9.4% of tomosynthesis exams). In the validation sample, the accuracy of identifying imaging findings, including suspicious calcifications, masses, and architectural distortion (on mammogram and tomosynthesis); masses, cysts, non-mass enhancement, and enhancing foci (on MRI); and masses and cysts (on ultrasound), range from 0.8 to1.0 for recall, precision, and F-measure. Information extraction tools can be used for accurate documentation of imaging findings as structured data elements from text reports for a variety of breast imaging modalities. These data can be used to populate screening registries to help elucidate more effective breast cancer screening processes.

The Association Between Use of Chiropractic Care and Costs of Care Among Older Medicare Patients With Chronic Low Back Pain and Multiple Comorbidities

OBJECTIVE

The purpose of this study was to determine whether use of chiropractic manipulative treatment (CMT) was associated with lower healthcare costs among multiply-comorbid Medicare beneficiaries with an episode of chronic low back pain (cLBP).

METHODS

We conducted an observational, retrospective study of 2006 to 2012 Medicare fee-for-service reimbursements for 72326 multiply-comorbid patients aged 66 and older with cLBP episodes and 1 of 4 treatment exposures: chiropractic manipulative treatment (CMT) alone, CMT followed or preceded by conventional medical care, or conventional medical care alone. We used propensity score weighting to address selection bias.

RESULTS

After propensity score weighting, total and per-episode day Part A, Part B, and Part D Medicare reimbursements during the cLBP treatment episode were lowest for patients who used CMT alone; these patients had higher rates of healthcare use for low back pain but lower rates of back surgery in the year following the treatment episode. Expenditures were greatest for patients receiving medical care alone; order was irrelevant when both CMT and medical treatment were provided. Patients who used only CMT had the lowest annual growth rates in almost all Medicare expenditure categories. While patients who used only CMT had the lowest Part A and Part B expenditures per episode day, we found no indication of lower psychiatric or pain medication expenditures associated with CMT.

CONCLUSIONS

This study found that older multiply-comorbid patients who used only CMT during their cLBP episodes had lower overall costs of care, shorter episodes, and lower cost of care per episode day than patients in the other treatment groups. Further, costs of care for the episode and per episode day were lower for patients who used a combination of CMT and conventional medical care than for patients who did not use any CMT. These findings support initial CMT use in the treatment of, and possibly broader chiropractic management of, older multiply-comorbid cLBP patients.

Comparing Propensity Score Methods for Creating Comparable Cohorts of Chiropractic Users and Nonusers in Older, Multiply Comorbid Medicare Patients With Chronic Low Back Pain

OBJECTIVE

Patients who use complementary and integrative health services like chiropractic manipulative treatment (CMT) often have different characteristics than do patients who do not, and these differences can confound attempts to compare outcomes across treatment groups, particularly in observational studies when selection bias may occur. The purposes of this study were to provide an overview on how propensity scoring methods can be used to address selection bias by balancing treatment groups on key variables and to use Medicare data to compare different methods for doing so.

METHODS

We described 2 propensity score methods (matching and weighting). Then we used Medicare data from 2006 to 2012 on older, multiply comorbid patients who had a chronic low back pain episode to demonstrate the impact of applying methods on the balance of demographics of patients between 2 treatment groups (those who received only CMT and those who received no CMT during their episodes).

RESULTS

Before application of propensity score methods, patients who used only CMT had different characteristics from those who did not. Propensity score matching diminished observed differences across the treatment groups at the expense of reduced sample size. However, propensity score weighting achieved balance in patient characteristics between the groups and allowed us to keep the entire sample.

CONCLUSIONS

Although propensity score matching and weighting have similar effects in terms of balancing covariates, weighting has the advantage of maintaining sample size, preserving external validity, and generalizing more naturally to comparisons of 3 or more treatment groups. Researchers should carefully consider which propensity score method to use, as using different methods can generate different results.

Risk Factors for Reoperation in Patients Treated Surgically for Intervertebral Disc Herniation: A Subanalysis of Eight-Year SPORT Data

BACKGROUND

Lumbar discectomy and laminectomy in patients with intervertebral disc herniation (IDH) is common, with variable reported reoperation rates. Our study examined which baseline characteristics might be risk factors for reoperation and compared outcomes between patients who underwent reoperation and those who did not.

METHODS

We performed a retrospective subgroup analysis of patients from the IDH arm of the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts. We analyzed baseline characteristics and outcomes of patients who underwent reoperation and those who did not with use of data collected from enrollment through eight-years of follow-up after surgery. Follow-up times were measured from the time of surgery, and baseline covariates were updated to the follow-up immediately preceding the time of surgery for outcomes analyses.

RESULTS

At eight years, the reoperation rate was 15% (691 no reoperation; 119 reoperation). Sixty-two percent of these patients underwent reoperation because of a recurrent disc herniation; 25%, because of a complication or other factor; and 11%, because of a new condition. The proportion of reoperations that were performed for a recurrent disc herniation ranged from 58% to 62% in the individual years. Older patients were less likely to have reoperation (p = 0.015), as were patients presenting with asymmetric motor weakness at baseline (p = 0.0003). Smoking, diabetes, obesity, Workers' Compensation, and clinical depression were not associated with a greater risk of reoperation. Scores on the Short Form (SF)-36 for bodily pain and physical functioning, the Oswestry Disability Index (ODI), and the Sciatica Bothersomeness Index as well as satisfaction with symptoms had improved less at the time of follow-up in the reoperation group (p < 0.001).

CONCLUSIONS

In patients who underwent surgery for IDH, the overall reoperation rate was 15% at the eight-year follow-up. Patients of older age and patients presenting with asymmetric motor weakness were less likely to undergo a reoperation. Less improvement in patient-reported outcomes was noted in the reoperation group.

SPORT: Does incidental durotomy affect longterm outcomes in cases of spinal stenosis?

BACKGROUND

Incidental durotomy is a familiar encounter during surgery for lumbar spinal stenosis. The impact of durotomy on long-term outcomes remains a matter of debate.

OBJECTIVE

To determine the impact of durotomy on the long-term outcomes of patients in the Spine Patient Outcomes Research Trial (SPORT).

METHODS

The SPORT cohort participants with a confirmed diagnosis of spinal stenosis, without associated spondylolisthesis, undergoing standard, first-time, open decompressive laminectomy, with or without fusion, were followed up from baseline at 6 weeks, and 3, 6, and 12 months and yearly thereafter at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean follow-up among all analyzed patients was 43.8 months.

RESULTS

Four hundred nine patients underwent first-time open laminectomy with or without fusion. Thirty-seven of these patients (9%) had an incidental durotomy. No significant differences were observed with or without durotomy in age; sex; race; body mass index; the prevalence of smoking, diabetes mellitus, and hypertension; decompression level; number of levels decompressed; or whether an additional fusion was performed. The durotomy group had significantly increased operative duration, operative blood loss, and inpatient stay. There were, however, no differences in incidence of nerve root injury, mortality, additional surgeries, or primary outcomes (Short Form-36 Bodily Pain or Physical Function scores or Oswestry Disability Index) at yearly follow-ups to 4 years.

CONCLUSIONS

Incidental durotomy during first-time lumbar laminectomy for spinal stenosis did not impact long-term outcomes in affected patients.

Early Versus Delayed Initiation of Concurrent Palliative Oncology Care: Patient Outcomes in the ENABLE III Randomized Controlled Trial

PURPOSE

Randomized controlled trials have supported integrated oncology and palliative care (PC); however, optimal timing has not been evaluated. We investigated the effect of early versus delayed PC on quality of life (QOL), symptom impact, mood, 1-year survival, and resource use.

PATIENTS AND METHODS

Between October 2010 and March 2013, 207 patients with advanced cancer at a National Cancer Institute cancer center, a Veterans Affairs Medical Center, and community outreach clinics were randomly assigned to receive an in-person PC consultation, structured PC telehealth nurse coaching sessions (once per week for six sessions), and monthly follow-up either early after enrollment or 3 months later. Outcomes were QOL, symptom impact, mood, 1-year survival, and resource use (hospital/intensive care unit days, emergency room visits, chemotherapy in last 14 days, and death location).

RESULTS

Overall patient-reported outcomes were not statistically significant after enrollment (QOL, P = .34; symptom impact, P = .09; mood, P = .33) or before death (QOL, P = .73; symptom impact, P = .30; mood, P = .82). Kaplan-Meier 1-year survival rates were 63% in the early group and 48% in the delayed group (difference, 15%; P = .038). Relative rates of early to delayed decedents' resource use were similar for hospital days (0.73; 95% CI, 0.41 to 1.27; P = .26), intensive care unit days (0.68; 95% CI, 0.23 to 2.02; P = .49), emergency room visits (0.73; 95% CI, 0.45 to 1.19; P = .21), chemotherapy in last 14 days (1.57; 95% CI, 0.37 to 6.7; P = .27), and home death (27 [54%] v 28 [47%]; P = .60).

CONCLUSION

Early-entry participants' patient-reported outcomes and resource use were not statistically different; however, their survival 1-year after enrollment was improved compared with those who began 3 months later. Understanding the complex mechanisms whereby PC may improve survival remains an important research priority.

Analysis of palliative care studies with joint models for quality-of-life measures and survival

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Background: In palliative care studies, the primary outcomes are often health related quality of life measures (HRLQ). Randomized trials and prospective cohorts typically recruit patients with advanced stage of disease and follow them until death or end of the study. During this time, HRLQ measures are collected at regular intervals. The typical analysis involves comparing the means of two or more intervention or exposure groups at specific times from entry into the study. An important feature of such studies is that, by design, some patients, but not all, are likely to die during the course of the study. For instance, in the Dartmouth ENABLE II study (Bakitas et al., 2009), 60% of patients died during the study. This feature affects the interpretation of the conventional analysis of palliative care trials and suggests the need for specialized methods of analysis. Methods: We have developed a “terminal decline model” for palliative care trials that, by jointly modeling the time until death and the HRQL measures, leads to flexible interpretation and efficient analysis of the trial data (Li, Tosteson, Bakitas, 2012). Importantly, it allows the estimation of the quality of life in the months preceding death, and specifically incorporates data for patients not dying during the study. At the same time, it permits the efficient estimation and interpretation of HRQL effects as measured in the conventional analysis as the difference in HRQL at specified times from enrollment conditional on being alive. Finally, it allows the estimation of the HRQL weighted survival or quality adjusted life years (QALY). Results: Based on the terminal decline model, survival distributions are shown affect the conventional estimates of HRQL trends in palliative care trials. A direct estimate for quality of life at specified times prior to death is provided. The methods are illustrated with ENABLE II data as an approach for improving the conduct of palliative care studies. Conclusions: Proper interpretation of palliative care studies requires consideration of the joint distribution of quality of life measures and survival as in the terminal decline model.

Using instrumental variables to estimate a Cox's proportional hazards regression subject to additive confounding

The estimation of treatment effects is one of the primary goals of statistics in medicine. Estimation based on observational studies is subject to confounding. Statistical methods for controlling bias due to confounding include regression adjustment, propensity scores and inverse probability weighted estimators. These methods require that all confounders are recorded in the data. The method of instrumental variables (IVs) can eliminate bias in observational studies even in the absence of information on confounders. We propose a method for integrating IVs within the framework of Cox's proportional hazards model and demonstrate the conditions under which it recovers the causal effect of treatment. The methodology is based on the approximate orthogonality of an instrument with unobserved confounders among those at risk. We derive an estimator as the solution to an estimating equation that resembles the score equation of the partial likelihood in much the same way as the traditional IV estimator resembles the normal equations. To justify this IV estimator for a Cox model we perform simulations to evaluate its operating characteristics. Finally, we apply the estimator to an observational study of the effect of coronary catheterization on survival.

Effect of head impacts on diffusivity measures in a cohort of collegiate contact sport athletes

OBJECTIVE

To determine whether exposure to repetitive head impacts over a single season affects white matter diffusion measures in collegiate contact sport athletes.

METHODS

A prospective cohort study at a Division I NCAA athletic program of 80 nonconcussed varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 79 non-contact sport athletes. Assessment occurred preseason and shortly after the season with diffusion tensor imaging and neurocognitive measures.

RESULTS

There was a significant (p = 0.011) athlete-group difference for mean diffusivity (MD) in the corpus callosum. Postseason fractional anisotropy (FA) differed (p = 0.001) in the amygdala (0.238 vs 0.233). Measures of head impact exposure correlated with white matter diffusivity measures in several brain regions, including the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory.

CONCLUSION

This study suggests a relationship between head impact exposure, white matter diffusion measures, and cognition over the course of a single season, even in the absence of diagnosed concussion, in a cohort of college athletes. Further work is needed to assess whether such effects are short term or persistent.

Intended versus inferred care after PET performed for initial staging in the National Oncologic PET Registry

The National Oncologic PET Registry (NOPR) collected data on intended management before and after PET in cancer patients. We have previously reported that PET was associated with a change in intended management of about one third of patients and was consistent across cancer types. It is uncertain if intended management plans reflect the actual care these patients received. One approach to assess actual care received is using administrative claims to categorize the type and timing of clinical services.

METHODS

NOPR data from 2006 to 2008 were linked to Medicare claims for consenting patients aged 65 y or older undergoing initial-staging PET scanning for bladder, ovarian, pancreatic, small cell lung, or stomach cancers. We determined the 60-d agreement between claims-inferred care and NOPR treatment plans.

RESULTS

Patients (n = 4,661) were assessed, and 30%-52% had metastatic disease. Planned treatments were about two-thirds monotherapy, of which 46% was systemic therapy only, and one-third combinations. Claims paid by 60 d confirmed the NOPR plan of any systemic therapy, radiotherapy, or surgery in 79.3%, 64.7%, and 63.6%, respectively. Single-mode plans were much more often confirmed: systemic therapy in more than 85% of patients with ovarian, pancreatic, and small cell lung cancers and surgery in more than 73% of those with bladder, pancreatic, and stomach cancers. Intended combination treatments had claims for both in only 28% of patients receiving surgery-based combinations and in 55% receiving chemoradiotherapy. About 90% of patients with NOPR-planned systemic therapy had evaluation or management claims from a medical oncologist. An age of less than 75 y was associated more often with confirmation of chemotherapy, less often for radiotherapy but not with confirmation of surgery. Performance status or comorbidity did not explain confirmation rates within action categories, but confirmation rates were higher if the referrer specialized in the planned treatment.

CONCLUSION

Claims confirmations of NOPR intent for initial staging were widely variable but were higher than previously reported for restaging PET, suggesting that measuring change in intended management is a reasonable method for assessing the impact diagnostic tests have on actual care.

SPORT: does incidental durotomy affect long-term outcomes in cases of spinal stenosis?

BACKGROUND

Incidental durotomy is a familiar encounter during surgery for lumbar spinal stenosis. The impact of durotomy on long-term outcomes remains a matter of debate.

OBJECTIVE

To determine the impact of durotomy on the long-term outcomes of patients in the Spine Patient Outcomes Research Trial (SPORT).

METHODS

The SPORT cohort participants with a confirmed diagnosis of spinal stenosis, without associated spondylolisthesis, undergoing standard, first-time, open decompressive laminectomy, with or without fusion, were followed up from baseline at 6 weeks, and 3, 6, and 12 months and yearly thereafter at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean follow-up among all analyzed patients was 43.8 months.

RESULTS

Four hundred nine patients underwent first-time open laminectomy with or without fusion. Thirty-seven of these patients (9%) had an incidental durotomy. No significant differences were observed with or without durotomy in age; sex; race; body mass index; the prevalence of smoking, diabetes mellitus, and hypertension; decompression level; number of levels decompressed; or whether an additional fusion was performed. The durotomy group had significantly increased operative duration, operative blood loss, and inpatient stay. There were, however, no differences in incidence of nerve root injury, mortality, additional surgeries, or primary outcomes (Short Form-36 Bodily Pain or Physical Function scores or Oswestry Disability Index) at yearly follow-ups to 4 years.

CONCLUSIONS

Incidental durotomy during first-time lumbar laminectomy for spinal stenosis did not impact long-term outcomes in affected patients.

The increasing incidence of thyroid cancer: the influence of access to care

BACKGROUND

The rapidly rising incidence of papillary thyroid cancer may be due to overdiagnosis of a reservoir of subclinical disease. To conclude that overdiagnosis is occurring, evidence for an association between access to health care and the incidence of cancer is necessary.

METHODS

We used Surveillance, Epidemiology, and End Results (SEER) data to examine U.S. papillary thyroid cancer incidence trends in Medicare-age and non-Medicare-age cohorts over three decades. We performed an ecologic analysis across 497 U.S. counties, examining the association of nine county-level socioeconomic markers of health care access and the incidence of papillary thyroid cancer.

RESULTS

Papillary thyroid cancer incidence is rising most rapidly in Americans over age 65 years (annual percentage change, 8.8%), who have broad health insurance coverage through Medicare. Among those under 65, in whom health insurance coverage is not universal, the rate of increase has been slower (annual percentage change, 6.4%). Over three decades, the mortality rate from thyroid cancer has not changed. Across U.S. counties, incidence ranged widely, from 0 to 29.7 per 100,000. County papillary thyroid cancer incidence was significantly correlated with all nine sociodemographic markers of health care access: it was positively correlated with rates of college education, white-collar employment, and family income; and negatively correlated with the percentage of residents who were uninsured, in poverty, unemployed, of nonwhite ethnicity, non-English speaking, and lacking high school education.

CONCLUSION

Markers for higher levels of health care access, both sociodemographic and age-based, are associated with higher papillary thyroid cancer incidence rates. More papillary thyroid cancers are diagnosed among populations with wider access to healthcare. Despite the threefold increase in incidence over three decades, the mortality rate remains unchanged. Together with the large subclinical reservoir of occult papillary thyroid cancers, these data provide supportive evidence for the widespread overdiagnosis of this entity.

Microwave imaging for neoadjuvant chemotherapy monitoring: initial clinical experience

INTRODUCTION

Microwave tomography recovers images of tissue dielectric properties, which appear to be specific for breast cancer, with low-cost technology that does not present an exposure risk, suggesting the modality may be a good candidate for monitoring neoadjuvant chemotherapy.

METHODS

Eight patients undergoing neoadjuvant chemotherapy for locally advanced breast cancer were imaged longitudinally five to eight times during the course of treatment. At the start of therapy, regions of interest (ROIs) were identified from contrast-enhanced magnetic resonance imaging studies. During subsequent microwave examinations, subjects were positioned with their breasts pendant in a coupling fluid and surrounded by an immersed antenna array. Microwave property values were extracted from the ROIs through an automated procedure and statistical analyses were performed to assess short term (30 days) and longer term (four to six months) dielectric property changes.

RESULTS

Two patient cases (one complete and one partial response) are presented in detail and demonstrate changes in microwave properties commensurate with the degree of treatment response observed pathologically. Normalized mean conductivity in ROIs from patients with complete pathological responses was significantly different from that of partial responders (P value = 0.004). In addition, the normalized conductivity measure also correlated well with complete pathological response at 30 days (P value = 0.002).

CONCLUSIONS

These preliminary findings suggest that both early and late conductivity property changes correlate well with overall treatment response to neoadjuvant therapy in locally advanced breast cancer. This result is consistent with earlier clinical outcomes that lesion conductivity is specific to differentiating breast cancer from benign lesions and normal tissue.

Joint modeling quality of life and survival using a terminal decline model in palliative care studies

Palliative medicine is a relatively new specialty that focuses on preventing and relieving the suffering of patients facing life-threatening illness. For cancer patients, clinical trials have been carried out to compare concurrent palliative care with usual cancer care in terms of longitudinal measurements of quality of life (QOL) until death, and overall survival is usually treated as a secondary endpoint. It is known that QOL of patients with advanced cancer decreases as death approaches; however, in previous clinical trials, this association has generally not been taken into account when inferences about the effect of an intervention on QOL or survival have been made. We developed a new joint modeling approach, a terminal decline model, to study the trajectory of repeated measurements and survival in a recently completed palliative care study. This approach takes the association of survival and QOL into account by modeling QOL retrospectively from death. For those patients whose death times are censored, marginal likelihood is used to incorporate them into the analysis. Our approach has two submodels: a piecewise linear random intercept model with serial correlation and measurement error for the retrospective trajectory of QOL and a piecewise exponential model for the survival distribution. Maximum likelihood estimators of the parameters are obtained by maximizing the closed-form expression of log-likelihood function. An explicit expression of quality-adjusted life years can also be derived from our approach. We present a detailed data analysis of our previously reported palliative care randomized clinical trial.

Variation in outcomes across centers after surgery for lumbar stenosis and degenerative spondylolisthesis in the spine patient outcomes research trial

STUDY DESIGN

Retrospective review of a prospectively collected database.

OBJECTIVE

To examine whether short- and long-term outcomes after surgery for lumbar stenosis (SPS) and degenerative spondylolisthesis (DS) vary across centers.

SUMMARY OF BACKGROUND DATA

Surgery has been shown to be of benefit for both SPS and DS. For both conditions, surgery often consists of laminectomy with or without fusion. Potential differences in outcomes of these overlapping procedures across various surgical centers have not yet been investigated.

METHODS

Spine Patient Outcomes Research Trial cohort participants with a confirmed diagnosis of SPS or DS undergoing surgery were followed from baseline at 6 weeks, 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Baseline characteristics and short- and long-term outcomes were analyzed.

RESULTS

A total of 793 patients underwent surgery. Significant differences were found between centers with regard to patient race, body mass index, treatment preference, neurological deficit, stenosis location, severity, and number of stenotic levels. Significant differences were also found in operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and wound infection. When baseline differences were adjusted for, significant differences were still seen between centers in changes in patient functional outcome (Short Form-36 bodily pain and physical function, and Oswestry Disability Index) at 1 year after surgery. In addition, the cumulative adjusted change in the Oswestry Disability Index Score at 4 years significantly differed among centers, with Short Form-36 scores trending toward significance.

CONCLUSION

There is a broad and statistically significant variation in short- and long-term outcomes after surgery for SPS and DS across various academic centers, when statistically significant baseline differences are adjusted for. The findings suggest that the choice of center affects outcome after these procedures, although further studies are required to investigate which center characteristics are most important.

Spine patient outcomes research trial: do outcomes vary across centers for surgery for lumbar disc herniation?

BACKGROUND

Lumbar discectomy is the most commonly performed spine procedure. Academic spine centers with potentially differing caseloads and experience may have different outcomes.

OBJECTIVE

To determine whether the choice of center in which surgery is performed affects lumbar discectomy outcomes.

METHODS

Spine Patient Outcomes Research Trial participants with a confirmed diagnosis of intervertebral disc herniation undergoing standard first-time open discectomy were followed from baseline at 6 weeks, and 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Patient data from this prospective study were reviewed. Enrollment began in March 2000 and ended in November 2004.

RESULTS

Seven hundred ninety-two patients underwent first-time lumbar discectomy. Significant differences were found among centers in patient age and race, baseline levels of disability, and treatment preferences. There were no significant differences among the centers in other patient characteristics (eg, sex, body mass index, the prevalence of smoking, diabetes, or hypertension), or disease characteristics (herniation level or type). Some short-term outcomes varied significantly among centers, including operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and reoperation rate. However, there were no differences among the centers in incidence of nerve root injury, postoperative mortality, Short Form 36 scores of body pain or physical function, or Oswestry Disability Index at 4 years.

CONCLUSION

Although mean blood loss, risk of durotomy, length of stay, and rate of reoperation vary among academic spine centers performing lumbar discectomy, there appears to be no difference in long-term functional outcomes.

A proof of principle clinical trial to determine whether conjugated linoleic acid modulates the lipogenic pathway in human breast cancer tissue

Conjugated linoleic acid (CLA) is widely used as a "nutraceutical" for weight loss. CLA has anticancer effects in preclinical models, and we demonstrated in vitro that this can be attributed to the suppression of fatty acid (FA) synthesis. We tested the hypothesis that administration of CLA to breast cancer patients would inhibit expression of markers related to FA synthesis in tumor tissue, and that this would suppress tumor proliferation. Women with Stage I-III breast cancer were enrolled into an open label study and treated with CLA (1:1 mix of 9c,11t- and 10t,12c-CLA isomers, 7.5 g/d) for ≥ 10 days before surgery. Fasting plasma CLA concentrations measured pre- and post-CLA administration, and pre/post CLA tumor samples were examined by immunohistochemistry for Spot 14 (S14), a regulator of FA synthesis, FA synthase (FASN), an enzyme of FA synthesis, and lipoprotein lipase (LPL), the enzyme that allows FA uptake. Tumors were also analyzed for expression of Ki-67 and cleaved caspase 3. 24 women completed study treatment, and 23 tumors were evaluable for the primary endpoint. The median duration of CLA therapy was 12 days, and no significant toxicity was observed. S14 expression scores decreased (p = 0.003) after CLA administration. No significant change in FASN or LPL expression was observed. Ki-67 scores declined (p = 0.029), while cleaved caspase 3 staining was unaffected. Decrements in S14 or Ki-67 did not correlate with fasting plasma CLA concentrations at surgery. Breast tumor tissue expression of S14, but not FASN or LPL, was decreased after a short course of treatment with 7.5 g/day CLA. This was accompanied by reductions in the proliferation index. CLA consumption was well-tolerated and safe at this dose for up to 20 days. Overall, CLA may be a prototype compound to target fatty acid synthesis in breast cancers with a "lipogenic phenotype".

Adoptive cellular therapy using cells enriched for NKG2D+CD3+CD8+T cells after autologous transplantation for myeloma

The number of circulating lymphocytes on day 15 after transplantation correlates with improved survival in patients with myeloma, but the lymphocyte subset responsible is unknown. NKG2D is a natural killer (NK) cell activating receptor that mediates non-MHC restricted and TCR-independent cell lysis. Our preliminary results indicate that CD3(+)CD8(+) T cells expressing NKG2D may be a critical lymphocyte population. A phase II trial examined the feasibility of infusing ex vivo-expanded cells enriched for NKG2D(+)CD3(+)CD8(+) T cells at weeks 1, 2, 4, and 8 after an autologous transplantation. In addition, low-dose IL-2 (6 × 10(5) IU/m(2)/day) was administered for 4 weeks, beginning on the day of transplantation. Twenty-three patients were accrued and 19 patients are evaluable. There were no treatment-related deaths. All patients completed their course of IL-2 and demonstrated normal engraftment. When compared with patients with myeloma who underwent transplantation not receiving posttransplantation immune therapy, the treated patients demonstrated an increase in the number of circulating NKG2D(+)CD3(+)CD8(+) T cells/μL (P < .004), CD3(+)CD8(+) T cells/μL (P < .04), CD3(+)CD8(+)CD56(+) T cells/μL (P < .004), and NKG2D(+)CD3(-)CD56(+) T cells/μL (P < .003). Myeloma cell-directed cytotoxicity by the circulating mononuclear cells increased after transplantation (P < .002). When compared to posttransplantation IL-2 therapy alone in this patient population, the addition of cells enriched for NKG2D(+)CD3(+)CD8(+) T cells increased tumor-specific immunity, as demonstrated by enhanced lysis of autologous myeloma cells (P = .02). We postulate that this regimen that increased the number and function of the NKG2D(+)CD3(+)CD8(+) T cells after transplantation may improve clinical outcomes by eliminating residual malignant cells in vivo.