Confidence Intervals for Ratios of Means and Medians

Bonett, Douglas G.; Price, Robert M.

doi:10.3102/1076998620934125

Cited by 14 publications

(8 citation statements)

References 25 publications

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“…The spectrally averaged enhancement factor of 7.4 –1.3 +1.6 is obtained by comparing the median values for the distributions of emission intensity, which can be converted to a mean photon extraction efficiency η ≈ 6% for the device containing the metallic mirror. The 95% confidence levels for the enhancement factor are calculated according to ref . In the second approach, we adopt the method described by M. Gschrey et al and directly measure η for individual QDs in mesa-processed structures.…”

Section: Resultsmentioning

confidence: 99%

Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si

Holewa¹,

Sakanas²,

Gür³

et al. 2022

ACS Photonics

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Whereas the Si photonic platform is highly attractive for scalable optical quantum information processing, it lacks practical solutions for efficient photon generation. Self-assembled semiconductor quantum dots (QDs) efficiently emit photons in the telecom bands (1460–1625 nm) and allow for heterogeneous integration with Si. In this work, we report on a novel, robust, and industry-compatible approach for achieving single-photon emission from InAs/InP QDs heterogeneously integrated with a Si substrate. As a proof of concept, we demonstrate a simple vertical emitting device, employing a metallic mirror beneath the QD emitter, and experimentally obtained photon extraction efficiencies of ∼10%. Nevertheless, the figures of merit of our structures are comparable with values previously only achieved for QDs emitting at shorter wavelength or by applying technically demanding fabrication processes. Our architecture and the simple fabrication procedure allows for the demonstration of high-purity single-photon generation with a second-order correlation function at zero time delay, g (2)(τ = 0) < 0.02, without any corrections at continuous wave excitation at the liquid helium temperature and preserved up to 50 K. For pulsed excitation, we achieve the as-measured g (2)(0) down to 0.205 ± 0.020 (0.114 ± 0.020 with background coincidences subtracted).

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Section: Resultsmentioning

confidence: 99%

Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si

Holewa¹,

Sakanas²,

Gür³

et al. 2022

ACS Photonics

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“…To compare and estimate the relative contribution of the different intervals, following previous studies [ 19 ], we calculated the ratios between the different intervals. Specifically, because the diagnostic interval was the longest interval for the majority of cancers, following methods by Bonett and Price [ 36 ], we calculated the ratios of the diagnostic to the patient interval (DI/PI), the diagnostic to the treatment interval (DI/TI), and the patient to the treatment interval (PI/TI) with their respective 95% CI. This was only done for studies that reported the duration of all 3 intervals in the same sample of patients and intervals were considered to be significantly different when the 95% CI for their ratio excluded 1.…”

Section: Methodsmentioning

confidence: 99%

The patient, diagnostic, and treatment intervals in adult patients with cancer from high- and lower-income countries: A systematic review and meta-analysis

et al. 2022

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Background Longer time intervals to diagnosis and treatment are associated with worse survival for various types of cancer. The patient, diagnostic, and treatment intervals are considered core indicators for early diagnosis and treatment. This review estimated the median duration of these intervals for various types of cancer and compared it across high- and lower-income countries. Methods and findings We conducted a systematic review with meta-analysis (prospectively registered protocol CRD42020200752). Three databases (MEDLINE, Embase, and Web of Science) and information sources including grey literature (Google Scholar, OpenGrey, EThOS, ProQuest Dissertations & Theses) were searched. Eligible articles were published during 2009 to 2022 and reported the duration of the following intervals in adult patients diagnosed with primary symptomatic cancer: patient interval (from the onset of symptoms to first presentation to a healthcare professional), diagnostic interval (from first presentation to diagnosis), and treatment interval (from diagnosis to treatment start). Interval duration was recorded in days and study medians were combined in a pooled estimate with 95% confidence intervals (CIs). The methodological quality of studies was assessed using the Aarhus checklist. A total of 410 articles representing 68 countries and reporting on 5,537,594 patients were included. The majority of articles reported data from high-income countries (n = 294, 72%), with 116 (28%) reporting data from lower-income countries. Pooled meta-analytic estimates were possible for 38 types of cancer. The majority of studies were conducted on patients with breast, lung, colorectal, and head and neck cancer. In studies from high-income countries, pooled median patient intervals generally did not exceed a month for most cancers. However, in studies from lower-income countries, patient intervals were consistently 1.5 to 4 times longer for almost all cancer sites. The majority of data on the diagnostic and treatment intervals came from high-income countries. Across both high- and lower-income countries, the longest diagnostic intervals were observed for hematological (71 days [95% CI 52 to 85], e.g., myelomas (83 days [47 to 145])), genitourinary (58 days [50 to 77], e.g., prostate (85 days [57 to 112])), and digestive/gastrointestinal (57 days [45 to 67], e.g., colorectal (63 days [48 to 78])) cancers. Similarly, the longest treatment intervals were observed for genitourinary (57 days [45 to 66], e.g., prostate (75 days [61 to 87])) and gynecological (46 days [38 to 54], e.g., cervical (69 days [45 to 108]) cancers. In studies from high-income countries, the implementation of cancer-directed policies was associated with shorter patient and diagnostic intervals for several cancers. This review included a large number of studies conducted worldwide but is limited by survivor bias and the inherent complexity and many possible biases in the measurement of time points and intervals in the cancer treatment pathway. In addition, the subintervals that compose the diagnostic interval (e.g., primary care interval, referral to diagnosis interval) were not considered. Conclusions These results identify the cancers where diagnosis and treatment initiation may take the longest and reveal the extent of global disparities in early diagnosis and treatment. Efforts should be made to reduce help-seeking times for cancer symptoms in lower-income countries. Estimates for the diagnostic and treatment intervals came mostly from high-income countries that have powerful health information systems in place to record such information.

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“…Percent changes in service volumes were calculated for differences between the final fiscal year, 2020/2021, and the mean of the two preceding fiscal years, 2018/2019 and 2019/2020, using SAS Enterprise Guide 7.1 (28). We calculated 95% confidence intervals for the percent changes in rates per 100,000 residents based on the ratios of mean monthly values over both time periods using version 4.0.4 of the R Language for Statistical Computing (29,30).…”

Section: Discussionmentioning

confidence: 99%

The clinical and economic impact of a community-based, hybrid model of in-person and virtual care in a Canadian rural setting: A cross-sectional population-based comparative study

Fitzsimon

Belanger

Glazier

et al. 2022

Preprint

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Objectives: To determine the clinical and economic impact of a community-based, hybrid model of in-person and virtual care by comparing health-system performance of the rural jurisdiction where this model was implemented with neighbouring jurisdictions without such a model and the broader regional health system. Design: A cross-sectional comparative study. Setting: Ontario, Canada, with a focus on three largely rural public health units from April 1, 2018, until March 31, 2021. Participants: All residents of Ontario, Canada under the age of 105 eligible for the Ontario Health Insurance Plan (OHIP) during the study period. Interventions: An innovative, community-based, hybrid model of in-person and virtual care, the Virtual Triage and Assessment Centre (VTAC), was implemented in Renfrew County, Ontario on March 27, 2020. Main outcome measures: Primary outcome was change in emergency department (ED) visits anywhere in Ontario, secondary outcomes included changes in hospitalizations and health-system costs, using percent changes in mean monthly values of linked health-system administrative data for two years pre-implementation and one year post-implementation. Results: Renfrew County saw larger declines in ED visits (-34.4%, 95% confidence interval -41.9% to -26.0%) and hospitalizations (-11.1%, 95% confidence interval -19.7% to -1.5%), and slower growth in health-system costs than other rural regions studied. VTAC patients' low-acuity ED visits decreased by -32.9%, high-acuity visits increased by 8.2%, and hospitalizations increased by 30.0%. Conclusion: After implementing VTAC, Renfrew County saw reduced ED visits and hospitalizations and slower health-system cost growth compared to neighbouring rural jurisdictions. VTAC patients experienced reduced unnecessary ED visits and increased appropriate care. Community-based, hybrid models of in-person and virtual care may reduce the burden on emergency and hospital services in rural, remote and underserved regions. Further study is required to evaluate potential for scale and spread. Trial registration: Not applicable.

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Confidence Intervals for Ratios of Means and Medians

Cited by 14 publications

References 25 publications

Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si

Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si

The patient, diagnostic, and treatment intervals in adult patients with cancer from high- and lower-income countries: A systematic review and meta-analysis

The clinical and economic impact of a community-based, hybrid model of in-person and virtual care in a Canadian rural setting: A cross-sectional population-based comparative study

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