Lower Percentage Points of the Bonferroni Chi-Square Statistic: Tables of G. B. Beus and D. R. Jensen

Author(s):  
Heinz Kres
1980 ◽  
Vol 17 (01) ◽  
pp. 145-153 ◽  
Author(s):  
H. Solomon ◽  
M. A. Stephens

Many random variables arising in problems of geometric probability have intractable densities, and it is very difficult to find probabilities or percentage points based on these densities. A simple approximation, a generalization of the chi-square distribution, is suggested, to approximate such densities; the approximation uses the first three moments. These may be theoretically derived, or may be obtained from Monte Carlo sampling. The approximation is illustrated on random variables (the area, the perimeter, and the number of sides) associated with random polygons arising from two processes in the plane. Where it can be checked theoretically, the approximation gives good results. It is compared also with Pearson curve fits to the densities.


2007 ◽  
Vol 19 (1) ◽  
pp. 294
Author(s):  
R. C. S. Yadav ◽  
A. Sharma ◽  
G. N. Purohit

Morphological changes and in vitro nuclear maturation of buffalo cumulus–oocyte complexes (COCs) was evaluated subsequent to their cryopreservation by vitrification in solutions containing 4 M, 6 M, 8 M, and 10 M concentrations of glycerol (G) or ethylene glycol (EG) or their combination. COCs collected from buffalo ovaries by aspiration (n = 1342) were equilibrated in 50% of the vitrification solution and then placed in the vitrification solution (Dulbecco's phosphate-buffered saline+0.5M sucrose + 0.5% BSA + cryoprotectant). COCs were transferred to empty semen straws, kept over LN vapor for 2–3 min, and then plunged into LN. After 7–10 days of storage, COCs were warmed and evaluated for morphological damage. Morphologically normal COCs were cultured in vitro (9 replicates each with 5–10 oocytes in 50–100-µL culture drops) in TCM-199 medium supplemented with 5µgmL-1 FSH, 5µgmL-1 LH, and 1 ngmL-1 estradiol with 25mM HEPES, 0.25mM pyruvate, and antibiotics. The COCs were incubated for 24 h at 38±1°C and 5% CO2 in humidified air in a CO2 incubator and evaluated for nuclear maturation at the end of 24 h of culture. Freshly collected COCs were also matured in vitro and kept as controls (n=142). The proportions of COCs retrieved in morphologically normal form were compared by chi-square test; the arcsin transformed data of the proportions of oocytes matured was compared by Duncan's new multiple range test. The proportions of oocytes recovered in a morphologically normal form were highest in the 6M EG group (95.23%), followed by 8M EG (94.0%) and 6M G (90.6%) groups. At 10M concentration, a significantly (P <0.05) lower percentage of oocytes was morphologically normal. The morphological abnormalities recorded were change in shape, rupture of zona pellucida, and leakage of oocyte contents. A significantly higher (65.62%; P <0.05) proportion of fresh oocytes reached metaphase-II compared to oocytes vitrified in all concentrations of G and EG. The proportion of oocytes reaching metaphase-II increased with increasing concentrations of both G and EG, but at 10M concentration the proportion of oocytes reaching metaphase-II decreased. The proportions of COCs reaching metaphase-II in 4M, 6 M, 8M, and 10M glycerol were 6.9%, 21.2%, 25.7%, and 5.5%, respectively. The respective proportions of COCs reaching metaphase-II in 4M, 6 M, 8M, and 10M ethylene glycol were 21.9%, 34.3%, 40.8%, and 7.5%. No significant benefit of in vitro maturation of oocytes was seen for oocytes vitrified in a combination of both G and EG. It was concluded that although vitrification brings about some damage to the oocytes, yet it appears to be a good tool for oocyte cryopreservation, and 8M concentration of either G or EG appears to be optimum for vitrification of buffalo oocytes.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e18224-e18224
Author(s):  
Lori Keys Pender ◽  
Haleh Kadkhoda ◽  
Katie S. Lucero ◽  
Patti Repetto ◽  
Charlotte Warren ◽  
...  

e18224 Background: Immune checkpoint inhibitors (ICIs) are increasingly used in oncology care and produce a wide variety of immune-related adverse events (irAEs) that differ from toxicities of other systemic therapies. The objective of this study was to assess trends over time in oncologists’ knowledge, competence, and confidence managing irAEs. Methods: A series of online continuing medical education (CME) activities addressing irAEs was launched beginning in April 2014; 39 included multiple-choice knowledge/competence questions and a confidence question assessed on a 5-point Likert-type scale before and immediately after the activity. Activities that had at least 30 oncologists participate pre/post are included in this analysis. A pre-/post-assessment study design was used, and educational effect was assessed with chi-square tests. Analyses were conducted to examine trends in knowledge, competence, and confidence recognizing, identifying, and managing irAEs over four years on a quarterly basis. Weighted averages in each of the outcomes were calculated by quarter. Results: A total of 187,800 learners participated from April 2014-March 2018, including 96,177 physicians, of whom 25,127 were oncologists. The average increase pre- to post-test for 22 activities that asked a knowledge-based question was 18% (P < 0.001). The absolute increase from pre-test in 2014 (67%) to post-test in 2018 (87%) was 20 percentage points. For 16 activities with competence questions, the average increase from pre- to post-test was 8% (P < 0.001), and the absolute increase from pre-test in 2014 (39%) to post-test in 2017 (87%) was 48 percentage points. For 5 activities with a confidence question, the average increase from pre- to post-test was 8% (P < 0.05), and the mean rating pre-test in 2016 was 2.85 versus 3.53 post-test in 2018. Conclusions: Online CME is effective to improve oncologists’ knowledge, competence, and confidence managing irAEs; however, pre-test outcomes in 2018 demonstrate ongoing knowledge and competence gaps that should be addressed, and post-test confidence data indicate a persistent lack of confidence among oncologists even after participating in online CME.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e19367-e19367
Author(s):  
Kerin B. Adelson ◽  
Maureen Canavan ◽  
Sophia Mun ◽  
Cary Philip Gross ◽  
Naralys Sinanis ◽  
...  

e19367 Background: The OCM is a Centers for Medicare and Medicaid Services (CMS) alternative payment model, which seeks to curb costs while improving care for patients receiving systemic cancer therapy. CMS models the expected total cost (spending target) for each 6-month episode using historical, geographic and clinical factors including CTr participation. We evaluated the relationship between CTr participation, actual cost of care and performance in the OCM. Methods: We used claims for OCM episodes attributed to the Yale Cancer Center between July 2016 and July 2018. We stratified episodes by CTr participation and used t-tests and chi-square tests to compare total cost, drug costs (Part B and D) and whether actual episode costs were above or below CMS targets. Analyses were conducted for the total sample, and among the most common cancer types. Results: Among 9,387 OCM episodes (5,270 unique patients), 815 (8.7%) episodes involved a CTr. Among non-CTr patients, the mean Medicare cost per episode ($32,909) was modestly higher than the mean episode spending target ($31,746; p < 0.001), while in the CTr group, the mean Medicare cost per episode ($36,590) was substantially lower than the mean episode spending target ($48,124 p < 0.001). Mean drug cost was lower with CTr vs without ($15,650 vs $19,587, p < 0.001). Drug costs also accounted for a lower percentage of total costs for episodes with CTr vs not (41% vs 57%). CTr episodes were more likely to meet spending targets than non-CTr episodes (66% vs 56%, p < 0.001) overall and in breast, lung, and myeloma cancers, although only statistically significant for lung cancer (76% CTr vs 48% non-CTr, p < 0.001). Mean difference between target and actual costs was greater for episodes with CTr (- $11,534) than for episodes without CTr (+ $1,163) (p < 0.001). Conclusions: On average, episodes with CTr participation had substantially lower costs compared with their spending targets, while non-CTr episodes had slightly higher costs compared with their spending targets. While total cost of care was higher for episodes with CTr (as the CMS model predicts), drug costs were significantly lower. As drugs comprise a large proportion of total cost, lower drug costs in CTr episodes likely contribute to savings. Additional research should explore whether other OCM centers with higher rates of CTr participation are more likely to meet spending targets in value-based payment models.


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