Chris Lloyd

A comprehensive open-source library for exact required sample size in binary clinical trials.

Chris J Lloyd, Enrico Ripamonti

Journal article  |  2021  |  Contemp Clin Trials

We describe how we are creating a new and comprehensive R library solving the problem of exact sample size determination of RCTs. ..

Exact confidence limits after a group sequential single arm trial

Chris Lloyd

Journal article  |  2021  |  Statistics in Medicine

Group sequential single arm designs are common in phase II trials as well as attribute testing and acceptance sampling. After the ..

Reply to Drs Almendra‐Arao and Sotres‐Ramos regarding Barnard's concept of convexity and possible extensions

Enrico Ripamonti, Chris Lloyd

Journal article  |  2020  |  Pharmaceutical Statistics: the journal of applied statistics in the pharmaceutical industry

On p. 130 of his 1947's seminal paper, Barnard1 wrote: “we propose that in our ordering, the two points which, respectively, have ..

Growing rich without growing old: the impact of internal migration in China

M Chen, CJ Lloyd, PSF Yip

Journal article  |  2020  |  Asian Population Studies

In China in 2017, the elderly dependency ratio (EDR) – which is the number of elderly per 100 working-age population – was 14.8. T..

A scenario analysis of future Hong Kong age and labour force profiles and its implications

Chris J Lloyd, Raymond Kwok, Paul SF Yip

Journal article  |  2019  |  Journal of the Royal Statistical Society Series A: Statistics in Society

The consequences of reduced fertility and mortality on the age distribution are an issue for most developed countries, but especia..

Tests for noninferiority trials with binomial endpoints: A guide to modern and quasi-exact methods for biomedical researchers

Enrico Ripamonti, Chris J Lloyd

Journal article  |  2019  |  Pharmaceutical Statistics: the journal of applied statistics in the pharmaceutical industry

Applied statisticians and pharmaceutical researchers are frequently involved in the design and analysis of clinical trials where a..

A Note on the Area under the Gains Chart

Chris Lloyd

Journal article  |  2018  |  International Journal of Statistics in Medical Research

The Receiver Operating Characteristic (ROC) chart is well known in medicine and machine learning. In particular the area under the..

A new method of identifying target groups for pronatalist policy applied to Australia

Mengni Chen, Chris J Lloyd, Paul SF Yip

Journal article  |  2018  |  PLOS ONE

A country's total fertility rate (TFR) depends on many factors. Attributing changes in TFR to changes of policy is difficult, as t..

An exhaustive numerical assessment of alternative unconditional tests of a binary treatment effect

Chris J Lloyd, Enrico Ripamonti

Journal article  |  2018  |  JOURNAL OF STATISTICAL COMPUTATION AND SIMULATION

For testing the effectiveness of a treatment on a binary outcome, a bewildering range of methods have been proposed. How similar a..

Contemporary Frequentist Views of the 2 x 2 Binomial Trial

Enrico Ripamonti, Chris Lloyd, Piero Quatto

Journal article  |  2017  |  STATISTICAL SCIENCE

The 2 × 2 table is the simplest of data structures yet it is of immense practical importance. It is also just complex enough to pr..