Leveraging naturally occurring variation in financial stress to examine associations with inflammatory burden among older adults

BACKGROUND

Financial strain is associated with earlier disability and mortality, but causal links are underexplored, partly because it is unethical to randomise people to financial stress. This study leverages naturally occurring random variation in days since monthly Social Security payment arrival among older adults to test associations with inflammatory biomarkers.

METHODS

Biomarker data, including tumour necrosis factor (TNF)-α, interleukin (IL)-6 and C reactive protein (CRP), was collected from 2155 non-working healthy adults aged 70-79 years, participating in the Health, Aging and Body Composition Study. Days since payment arrival was independent of all demographic, socioeconomic or health characteristics measured in this study. Restricted cubic spline models estimated associations separately for each week of the month, stratified by financial strain status (interaction term p value for TNF-α model <0.05).

RESULTS

Among financially strained older adults, more days since payment arrival was associated with higher TNF-α levels during the first week of the month (coefficient=0.102). Associations with IL-6 and CRP differed depending on the degree of financial strain (interaction term p values <0.05). Those with low, but not high, strain had lower levels of IL-6 (coefficient=-0.152) and CRP (coefficient=-0.179) during the first week.

CONCLUSIONS

Days since monthly payments were associated with inflammatory cytokines among older adults who have difficulty making ends meet financially and associations depended on financial strain severity, suggesting that results are attributable to monthly variation in financial stress. Future research should examine whether more frequent Social Security disbursement would modify financial strain and inflammatory biomarkers.

Nurse practitioners' workforce outcomes under implementation of full practice authority

BACKGROUND

Full practice authority laws that permit nurse practitioners (NPs) to practice independently and prescribe medications may influence NPs' workforce outcomes.

PURPOSE

To examine whether implementation of full practice authority laws affect NP self-employment, average earnings, and likelihood of residing in a primary care health professional shortage area (HPSA).

METHODS

A nationally representative U.S. sample of 9,782 NPs employed in health care during 2010 to 2018 was drawn from the American Community Survey. Difference-in-differences regression was used to estimate covariate-adjusted mean differences in NPs' workforce outcomes after full practice authority implementation.

FINDINGS

Among full-time employed NPs, full practice authority was associated with an increased probability of residing in a HPSA (adjusted odds ratio [aOR]:2.34, 95%CI 1.14, 4.83) and with a higher mean probability of self-employment (aOR:4.97, 95%CI 1.00, 24.86).

DISCUSSION

Full practice authority implementation improves access to primary care providers in health professional shortage areas and may increase practice ownership among NPs.

Disentangling Race, Poverty, and Place to Understand the Racial Disparity in Waist Circumference among Women

In the U.S., 54.8% of non-Hispanic Black women are obese, a rate that is 1.4 times greater than in White women. The drivers of this racial disparity are not yet clearly understood. We sought to disentangle race, household poverty, neighborhood racial composition, and neighborhood poverty to better understand the racial disparity in obesity among women. We used data from the 1999-2004 National Health and Nutrition Examination Survey and the 2000 U.S. Census to examine the role of individual race, individual poverty, neighborhood racial composition, and neighborhood poverty on women's risk of obesity. We found that individual race was the primary risk factor for obesity among women. Neighborhood effects did not account for the racial disparity. Understanding that race is a social, not a biologic construct, more work is needed to uncover what it is about race that produces racial disparities in obesity among women.

ROBBING PETER TO PAY PAUL: HANDLING FINANCIAL CHALLENGES AMONG LOW-INCOME OLDER ADULTS

Low income older adults often face financial challenges which increase their risk for earlier disability and mortality. This study explored the social norms, beliefs and practices relevant to handling financial challenges among low-income community-dwelling older adults residing near Baltimore, MD whom we recruited using convenience and snowball sampling. Four vignette-based focus group sessions included 28 participants. Using hierarchical thematic analysis, three key themes emerged. First, the theme “Rob Peter to pay Paul” describes the consensus that individuals must prioritize financial needs, which required individuals to “work with a budget”, apply for aid, “cry for [aid]” and, when needed, “work something out” with landlords and lenders. One participant described the amount of work by saying “We’re retired but we’re working for ourselves.” Secondly, the theme “Your rent should be first” describes how low income older adults prioritize housing over food and other needs because “resources for housing is a problem” and because homelessness is both more permanent and socially stigmatizing than hunger - “Don’t nobody know you’re hungry unless you tell them, but everybody know when you outdoors.” Finally, the theme “We need to put the word out” describes the consensus that public benefits and community resources should be made more visible and accessible. Many individuals only know about resources because they seek information (“you go and you find out”), but “ it’s hard to ask for help. ” These results can inform the development and improvement of financial and community programs and policies for low-income older adults addressing financial challenges.

NATURALLY OCCURRING VARIABILITY IN FINANCIAL STRESS AND INFLAMMATORY BIOMARKERS AMONG OLDER ADULTS

Financial strain (i.e. difficulty making ends meet) is associated with earlier disability and mortality among older adults, but inflammatory response to financial stress is untested. This study leverages monthly increases in financial stress among older adults receiving Social Security payments monthly on the 3rd. The Health ABC Study randomly sampled black and white adults aged 70-79 free of disability from Memphis, TN and Pittsburgh, PA in 1997 and 1998. Baseline biomarkers included TNF α, IL-6, CRP, and soluble receptors were measured for about half the sample (IL-2, IL-6, and TNF α Type I and II). Days since Social Security payment was calculated using clinic visit date, which naturally varied in the sample. Restricted cubic spline models stratified by financial strain status tested hypothesized associations, adjusting for financial strain scores, food insecurity, employment status and monthly invariant potential confounders (age, gender, number of inflammatory conditions, waist circumference and anti-inflammatory medications). Among those with financial strain, each additional day since payment was associated with higher TNF-α levels during first week of the month (n=1,633, coefficient=0.0830, p=0.030) and higher IL-6 soluble receptor levels during the last week of the month (n=828, coefficient=12033.44, p=0.037), but not with other biomarkers nor during the middle of the month. Days since payment was not associated with biomarkers among those without financial strain. These results suggest upregulation of pro-inflammatory and not anti-inflammatory pathways during the beginning and end of the month among financially strained older adults. Financial strain is modifiable and these results call attention to addressing it.

Association of sex and atrial fibrillation therapies with patient-reported outcomes

OBJECTIVES

Women report higher atrial fibrillation (AF) symptom severity and receive less AF therapies than their male counterparts. It is understudied if differences in AF therapies received explains sex differences in AF symptom severity. We investigate the impact of sex and AF therapies on patient-reported outcomes.

METHODS

Participants were recruited (n=953) across four academic medical centres with an AF diagnosis and age ≥18 years. Patient-reported outcomes (AF symptom severity, AF-related quality of life, functional status and emotional status) were determined by biannual surveys. We performed multiple linear regressions on propensity-matched cohorts to determine the association of AF therapies and sex on patient-reported outcomes.

RESULTS

Our study population (n=953) was 65% male (n=616), 93% white (n=890) and 72 (±10) years old. Individuals receiving rate control therapy reported comparatively lower AF-related quality of life (-7.22, 95% CI -11.51 to -2.92) and poorer functional status (-3.69, 95% CI -5.27 to -2.12). Individuals receiving rhythm control strategies did not report significantly different patient-reported outcomes. Women were more likely to report poorer functional status (-2.63, 95% CI -3.86 to -1.40) and poorer AF-related quality of life, higher anxiety (2.33, 95% CI 1.07 to 3.59), higher symptoms of depression (1.48, 95% CI 0.31 to 2.65) and AF symptom severity (0.29, 95% CI 0.07 to 0.52).

CONCLUSIONS

Female sex was associated with comparatively poorer AF symptom severity and quality of life, and this association remained after accounting for AF therapies received. Receiving rate control medication alone was associated with comparatively poorer AF-related quality of life and functional status.

Association of sex, age and education level with patient reported outcomes in atrial fibrillation

BACKGROUND

In atrial fibrillation (AF), there are known sex and sociodemographic disparities in clinical outcomes such as stroke. We investigate whether disparities also exist with respect to patient-reported outcomes. We explored the association of sex, age, and education level with patient-reported outcomes (AF-related quality of life, symptom severity, and emotional and functional status).

METHODS

The PaTH AF cohort study recruited participants (N = 953) with an AF diagnosis and age ≥ 18 years across 4 academic medical centers. We performed longitudinal multiple regression with random effects to determine if individual characteristics were associated with patient-reported outcomes.

RESULTS

Women reported poorer functional status (β - 2.23, 95% CI: -3.52, - 0.94) and AF-related quality of life (β - 4.12, 95% CI: -8.10, - 0.14), and higher symptoms of anxiety (β 2.08, 95% CI: 0.76, 3.40), depression (β 1.44, 95% CI: 0.25, 2.63), and AF (β 0.29, 95% CI: 0.08, 0.50). Individuals < 60 years were significantly (p < 0.05) more likely to report higher symptoms of depression, anxiety, and AF, and poorer AF-related quality of life. Lack of college education was associated with reporting higher symptoms of AF (β 0.42, 95% CI: 0.17, 0.68), anxiety (β 1.86, 95% CI: 0.26, 3.45), and depression (β 1.11, 95% CI: 0.15, 2.38), and lower AF-related quality of life (β - 4.41, 95% CI: -8.25, - 0.57) and functional status.

CONCLUSION

Women, younger adults, and individuals with lower levels of education reported comparatively poor patient-reported outcomes. These findings highlight the importance of understanding why individuals experience AF differently based on certain characteristics.

Transcriptional subtyping and CD8 immunohistochemistry identifies poor prognosis stage II/III colorectal cancer patients who benefit from adjuvant chemotherapy

Purpose

Transcriptomic profiling of colorectal cancer (CRC) has led to the identification of four consensus molecular subtypes (CMS1 to 4) that have prognostic value in stage II and III disease. More recently, the Colorectal Cancer Intrinsic Subtypes (CRIS) classification system has helped to define the biology specific to the epithelial component of colorectal tumors; however, the clinical value of these classification systems in the prediction of response to standard-of-care adjuvant chemotherapy remains unknown.

Patients and Methods

Using samples from four European sites, we assembled a novel cohort of patients with stage II and III CRC (n = 156 samples) and performed transcriptomic profiling and targeted sequencing and generated a tissue microarray to enable integrated multiomics analyses. We also accessed data from two published cohorts of patients with stage II and III CRC: GSE39582 and GSE14333 (n = 479 and n = 185 samples, respectively).

Results

The epithelial-rich CMS2 subtype of CRC benefitted significantly from treatment with adjuvant chemotherapy in both stage II and III disease (P = .02 and P < .001, respectively), whereas the CMS3 subtype significantly benefitted in stage III only (P = .001). After CRIS substratification of CMS2, we observed that only the CRIS-C subtype significantly benefitted from treatment with adjuvant chemotherapy in stage II and III disease (P = .0081 and P < .001, respectively), whereas the CRIS-D subtype significantly benefitted in stage III only (P = .0034). We also observed that CRIS-C patients with low levels of CD8⁺ tumor-infiltrating lymphocytes were most at risk for relapse in both stage II and III disease (log-rank P = .0031; hazard ratio, 12.18 [95% CI, 1.51 to 98.58]).

Conclusion

Patient stratification using a combination of transcriptional subtyping and CD8 immunohistochemistry analyses is capable of identifying patients with poor prognostic stage II and III disease who benefit from adjuvant standard-of-care chemotherapy. These findings are particularly relevant for patients with stage II disease, where the overall benefit of adjuvant chemotherapy is marginal.

Prognostic value of lymph node ratio and extramural vascular invasion on survival for patients undergoing curative colon cancer resection

Background:

Increasing lymph node ratio (LNR) (ratio of metastatic lymph nodes to the total number of harvested lymph nodes) and extramural vascular invasion (EMVI) have been proposed as adverse prognostic indicators in colorectal cancer, although their use remains variable and controversial. The aim of the present study was to assess the prognostic value of LNR and EMVI in predicting survival for patients undergoing curative colon cancer resection.

Methods:

Between 2006 and 2012, 922 patients underwent curative colon cancer resection. Surgical technique and pathological assessment did not change during the study period. Clinical and pathological data were collected from a prospectively maintained database. The primary outcome measure was overall survival and disease-free survival. LNR was separated into five categories based on three previously calculated cutoff values: LNR 0 (no lymph nodes involved), LNR 1 (ratio 0.01<0.17), LNR 2 (ratio 0.18–0.41), LNR 3 (ratio 0.42–0.69), and LNR 4 (ratio >0.70).

Results:

Nine hundred and twenty-two patients underwent colon cancer resection. The median follow-up for survivors was 52.8 months (IQR 34.6–77.6). The median total number of lymph nodes harvested was 16 (IQR13-22). On multivariate analysis, both pN and LNR were strongly associated with overall and disease-free survival. Using the Akaike information criterion (AIC), LNR had greater prognostic value compared with pN. For overall survival, compared with patients in LNR category 0, hazard ratios (95% CI) for those in categories 1, 2, 3 and 4 were 1.37 (1.03,1.82), 2.37 (1.70,3.30), 2.40 (1.57,3.65) and 5.51 (3.16,9.58), respectively. For disease-free survival, patients had hazard ratios (95% CI) of 1.78 (1.25,2.52), 3.79 (2.56,5.61), 2.60 (1.50,4.48) and 4.76 (2.21,10.27), respectively. The presence of EMVI was a significant predictor of decreased overall and disease-free survival (P<0.001).

Conclusions:

This study demonstrated, in the presence of high surgical, oncology and pathological standards, EMVI and increasing LNR were independent predictors of decreased overall and disease-free survival for patients undergoing curative colon cancer resection. LNR was superior to pN stage in predicting overall and disease-free survival.

An analysis of sodium, total fat and saturated fat contents of packaged food products advertised in Bronx-based supermarket circulars

Americans' consumption of sodium, fat, and saturated fat exceed federally recommended limits for these nutrients and has been identified as a preventable leading cause of hypertension and cardiovascular disease. More than 40% of the Bronx population comprises African-Americans, who have increased risk and earlier onset of hypertension and are also genetically predisposed to salt-sensitive hypertension. This study analyzed nutrition information for packaged foods advertised in Bronx-based supermarket circulars. Federally recommended limits for sodium, saturated fat and total fat contents were used to identify foods that were high in these nutrients. The proportion of these products with respect to the total number of packaged foods was calculated. More than a third (35%) and almost a quarter (24%) of the 898 advertised packaged foods were high in saturated fat and sodium respectively. Such foods predominantly included processed meat and fish products, fast foods, meals, entrees and side dishes. Dairy and egg products were the greatest contributors of high saturated fat. Pork and beef products, fast foods, meals, entrees and side dishes had the highest median values for sodium, total fat and saturated fat content. The high proportion of packaged foods that are high in sodium and/or saturated fat promoted through supermarket circulars highlights the need for nutrition education among consumers as well as collaborative public health measures by the food industry, community and government agencies to reduce the amounts of sodium and saturated fat in these products and limit the promotion of foods that are high in these nutrients.

Transmission of infection to liver transplant recipients from donors with infective endocarditis: lessons learned

Donors not meeting standard criteria, such as those with bacteremia, are now being used in response to the increasing need for organs for transplantation. Recommended strategies to prevent the occurrence of donor-derived bacteremia include the use of directed antibiotic prophylaxis. However, this approach does not eliminate the risk of infection transmission. Similarly, the management of organ recipients from donors with infective endocarditis (IE) remains uncharacterized. We report 2 cases of donor-derived bacterial infections in liver transplant recipients despite pathogen-specific antibiotic prophylaxis. In both instances, the donors had documented IE treated with appropriate antimicrobial therapy and clearance of bacteremia. Recipients had very distinctive clinical outcomes likely related to pathogen virulence and the extent of donor infection. Persistent infection in the transplanted liver should be suspected in organ recipients of a liver from donors with IE, despite the absence of bacteremia at the time of death and organ procurement. For eradication, recipients may require prolonged pathogen-directed antimicrobial therapy, such as is used for endovascular infections. Prompt recognition of donors with IE, appropriate notification, and prolonged antibiotic prophylaxis are key to reducing the risk of such donor-derived infections.

Tumour- and treatment-related colostomy rates following mitomycin C or cisplatin chemoradiation with or without maintenance chemotherapy in squamous cell carcinoma of the anus in the ACT II trial

BACKGROUND

Squamous cell carcinoma of the anus (SCCA) is highly sensitive to chemoradiation (CRT) which achieves good loco-regional control and preserves anal function. However, some patients require permanent stoma formation either as a result of surgery on relapse, poor anal function or treatment-related symptoms. Our aim was to determine patient, tumour and treatment-related colostomy rates following CRT and maintenance chemotherapy in the ACT II trial.

PATIENTS AND METHODS

The ACT II trial recruited 940 patients comparing 5FU-based CRT using cisplatin (CisP) or mitomycin C (MMC) with or without additional maintenance chemotherapy. We investigated the association between colostomy-free survival (CFS) and progression-free survival (PFS) with age, gender, T-stage, N-stage, treatment and baseline haemoglobin.

RESULTS

The median follow-up was 5.1 years (n = 884 evaluable/940); tumour site canal (84%), margin (14%); stage T1/T2 (52%), T3/T4 (46%); N+ (32%), N0 (62%). Twenty out of 118 (17%) colostomies fashioned before CRT were reversed within 8 months. One hundred and twelve patients had a post-treatment colostomy due to persistent disease (98) or morbidity (14). Fifty-two per cent (61/118) of all pre-treatment colostomies were never reversed. The 5-year CFS rates were 68% MMC/Maint, 70% CisP/Maint, 68% MMC/No-maint and 65% CisP/No-maint. CRT with CisP did not improve CFS when compared with MMC (hazard ratio: 1.04, 95% confidence interval: 0.82-1.31, P = 0.74). The 5-year CFS rates were higher for T1/T2 (79%) than T3/T4 (54%) tumours and higher for node-negative (72%) than node-positive (60%) patients. Significant predictors of CFS were gender, T-stage and haemoglobin, while treatment factors had no impact on outcome. Similar associations were found between PFS and tumour/treatment-related factors.

CONCLUSIONS

The majority (52%) of pre-treatment colostomies were never reversed. Neither CRT with 5FU/CisP nor maintenance chemotherapy impacted on CFS. The low risk of colostomy for late effects (1.7%) is likely to be associated with the modest total radiotherapy dose. The predictive factors for CFS were T-stage, gender and baseline haemoglobin.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN 26715889.

Time from first presentation in primary care to treatment of symptomatic colorectal cancer: effect on disease stage and survival

Background:

British 5-year survival from colorectal cancer (CRC) is below the European average, but the reasons are unclear. This study explored if longer provider delays (time from presentation to treatment) were associated with more advanced stage disease at diagnosis and poorer survival.

Methods:

Data on 958 people with CRC were linked with the Scottish Cancer Registry, the Scottish Death Registry and the acute hospital discharge (SMR01) dataset. Time from first presentation in primary care to first treatment, disease stage at diagnosis and survival time from date of first presentation in primary care were determined. Logistic regression and Cox survival analyses, both with a restricted cubic spline, were used to model stage and survival, respectively, following sequential adjustment of patient and tumour factors.

Results:

On univariate analysis, those with <4 weeks from first presentation in primary care to treatment had more advanced disease at diagnosis and the poorest prognosis. Treatment delays between 4 and 34 weeks were associated with earlier stage (with the lowest odds ratio occurring at 20 weeks) and better survival (with the lowest hazard ratio occurring at 16 weeks). Provider delays beyond 34 weeks were associated with more advanced disease at diagnosis, but not increased mortality. Following adjustment for patient, tumour factors, emergency admissions and symptoms and signs, no significant relationship between provider delay and stage at diagnosis or survival from CRC was found.

Conclusions:

Although allowing for a nonlinear relationship and important confounders, moderately long provider delays did not impact adversely on cancer outcomes. Delays are undesirable because they cause anxiety; this may be fuelled by government targets and health campaigns stressing the importance of very prompt cancer diagnosis. Our findings should reassure patients. They suggest that a health service's primary emphasis should be on quality and outcomes rather than on time to treatment.

Currently recommended BK virus (BKV) plasma viral load cutoff of ≥4 log10/mL underestimates the diagnosis of BKV-associated nephropathy: a single transplant center experience

BACKGROUND

BK virus (BKV)-associated nephropathy (BKVAN) is a major cause of renal dysfunction and graft loss in renal transplant recipients. Monitoring plasma BK viral load (BKVL) is the recommended screening tool to predict BKVAN. American Society of Transplantation (AST) guidelines define a BKVL of ≥4 log10/mL (10,000 copies) as presumptive BKVAN and recommend reduction in immunosuppression. We evaluated the clinical sensitivity of the quantitative BKV DNA assay in predicting risk for BKVAN using the AST-recommended BKVL cutoff.

METHODS

In a retrospective, single-center study, all patients who underwent renal transplant at Henry Ford Hospital from January 2008 to August 2011 were analyzed (n = 490). Plasma BKVL Assay A (commercial large T antigen-based polymerase chain reaction [PCR]) was done in all patients. Renal biopsy was done if there was a rise in serum creatinine ≥0.5 mg from baseline. BKVAN was confirmed by biopsy. As a subset to this study, from the same cohort, data for a set of 20 consecutive Assays A and B (in-house VP1-based PCR assay) from 15 patients over a period of 3 months were collected. Differences in physicians' clinical decision-making (CDM) were analyzed between the 2 assays using chi-square test.

RESULTS

A total of 413 patients met the inclusion criteria, of which 222 patients had BK viremia. Among the 248 patients who had a renal biopsy done, 31 (12.5%) were found to have BKVAN. Eleven of the 31 (35%) patients had BKVL consistently <4 log10/mL, and thus were not diagnosed to have BKVAN using the AST-recommended BKVL cutoff of ≥4 log10/mL. A total of 8 patients lost their graft owing to BKVAN, including 3 patients with BKVL <4 log10/mL. Using a cutoff point of plasma BKVL of ≥4 log10/mL, the sensitivity, specificity, positive predictive value, and negative predicative value of the PCR Assay A for the diagnosis of biopsy-proven BKVAN were 64.5%, 98.4%, 87.0%, and 94.5%, respectively, and for the diagnosis of presumptive nephropathy were found to be 76.6%, 99.4%, 95.8%, and 96.4%, respectively. In the second part of the study, presumptive nephropathy was detected in 8 samples using Assay A and 14 samples using Assay B. Six samples in Assay A would have led to no changes in the CDM in terms of reduction in immunosuppression. Kidney biopsy was carried out in 5 patients, 4 of whom had BKVAN and had Assay B log count of ≥5. If Assay A had been used in CDM, BKVAN would have been missed in 1 patient.

CONCLUSION

Utilizing the current AST guideline cutoff of ≥4 log10 /mL, the PCR Assay A underestimated the diagnosis of BKVAN. Urgent standardization of the various BKVL assays and establishment of universal cutoff points is imperative to avoid BKVAN-related graft loss.

Evaluation of corn hybrids expressing Cry1F, cry1A.105, Cry2Ab2, Cry34Ab1/Cry35Ab1, and Cry3Bb1 against southern United States insect pests

Studies were conducted across the southern United States to characterize the efficacy of multiple Bacillus thuringiensis (Bt) events in a field corn, Zea mays L., hybrid for control of common lepidopteran and coleopteran pests. Cry1F protein in event TC1507 and Cry1A.105 + Cry2Ab2 proteins in event MON 89034 were evaluated against pests infesting corn on above-ground plant tissue including foliage, stalks, and ears. Cry34Ab1/Cry35Ab1 proteins in event DAS-59122-7 and Cry3Bb1 in event MON 88017 were evaluated against the larvae of Mexican corn rootworm, Diabrotica virgifera zeae Krysan and Smith, which occur below-ground. Field corn hybrids containing Cry1F, Cry1A.105 + Cry2Ab2, Cry34Ab1/Cry35Ab1, and Cry3Bb1 insecticidal proteins (SmartStax) consistently demonstrated reductions in plant injury and/or reduced larval survivorship as compared with a non-Bt field corn hybrid. Efficacy provided by a field corn hybrid with multiple Bt proteins was statistically equal to or significantly better than corn hybrids containing a single event active against target pests. Single event field corn hybrids provided very high levels of control of southwestern corn borer, Diatraea grandiosella (Dyar), lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), and fall armyworm, Spodoptera frugiperda (J.E. Smith), and were not significantly different than field corn hybrids with multiple events. Significant increases in efficacy were observed for a field corn hybrid with multiple Bt events for sugarcane borer, Diatraea saccharalis (F.), beet armyworm, Spodoptera exigua (Hübner), corn earworm, Helicoverpa zea (Boddie), and Mexican corn rootworm. Utilization of field corn hybrids containing multiple Bt events provides a means for managing insect resistance to Bt proteins and reduces non-Bt corn refuge requirements.