Bypassing the selection rule in choosing controls for a case-control study

Objectives It has been argued that in case–control studies, controls should be drawn from the base population that gives rise to the cases. In designing a study of occupational injury and risks arising from long-term illness and prescribed medication, we lacked data on subjects' occupation, without which employed cases (typically in manual occupations) would be compared with controls from the general population, including the unemployed and a higher proportion of white-collar professions. Collecting the missing data on occupation would be costly. We estimated the potential for bias if the selection rule were ignored. Methods: We obtained published estimates of the frequencies of several exposures of interest (diabetes, mental health problems, asthma, coronary heart disease) in the general population, and of the relative risks of these diseases in unemployed versus employed individuals and in manual versus non-manual occupations. From these we computed the degree of over- or underestimation of exposure frequencies and exposure ORs if controls were selected from the general population. Results: The potential bias in the OR was estimated as likely to fall between an underestimation of 14% and an overestimation of 36.7% (95th centiles). In fewer than 6% of simulations did the error exceed 30%, and in none did it reach 50%. Conclusions: For the purposes of this study, in which we were interested only in substantial increases in risk, the potential for selection bias was judged acceptable. The rule that controls should come from the same base population as cases can justifiably be broken, at least in some circumstances. <br/

Lord Sumption and the Values of Life, Liberty, and Security:Before and Since the COVID-19 Outbreak

Lord Sumption, a former Justice of the Supreme Court, has been a prominent critic of coronavirus restrictions regulations in the UK. Since the start of the pandemic, he has consistently questioned both the policy aims and the regulatory methods of the Westminster government. He has also challenged rationales that hold that all lives are of equal value. In this paper, I explore and question Lord Sumption’s views on morality, politics and law, querying the coherence of his broad philosophy and his arguments regarding coronavirus regulations with his judicial decision in the assisted-dying case of R (Nicklinson) v Ministry of Justice. In Nicklinson, Lord Sumption argued for restrictions on liberty given the priority of the sanctity of life principle and the protection of others who may be vulnerable, as well as for deference to policy-making institutions in instances of values-based disagreement. The apparent inconsistencies in his positions, I argue, are not clearly reconcilable, and invite critical analysis of his impacts on health law and policy

Confrontations in "genethics": Rationalities, challenges, and methodological responses

It was only a matter of time before the portmanteau term “genethics” would be coined and a whole field within bioethics delineated. The term can be dated back at least to 1984 and the work of James Nagle, who claims credit for inventing the word, which he takes “to incorporate the various ethical implications and dilemmas generated by genetic engineering with the technologies and applications that directly or indirectly affect the human species.” In Nagle’s phrase, “Genethic issues are instances where medical genetics and biotechnology generate ethical problems that warrant societal deliberation.” The great promises and terrific threats of developments in scientific understanding of genetics, and the power to enhance, modify, or profit from the knowledge science breeds, naturally offer a huge range of issues to vex moral philosophers and social theorists. Issues as diverse as embryo selection and the quest for immortality continue to tax analysts, who offer reasons as varied as the matters that might be dubbed “genethical” for or against the morality of things that are actually possible, logically possible, and even just tenuously probable science fictio

Transesterification of triolein by solid catalysts

In this thesis, biodiesel was produced by the transesterification of triolein. Initially a method utilizing gas chromatography was developed to monitor the Novozym 435 catalyzed transesterification. After the procedure was established, experiments were conducted to determine the effect and existence of interactions between reaction parameters including catalyst mass, agitation speed, methanol to triolein ratio, and temperature on yield. A split plot design showed that all single parameters were significant except methanol to triolein ratio. Several two way interactions were found including temperature over ratio, temperature over catalyst mass, and extent of agitation over catalyst mass. The extent of agitation over catalyst mass interaction proved to be the most significant of all the two way interactions experimentally and this interaction could be verified visually. A three way interaction is also present among agitation speed, methanol to triolein ratio, and the catalyst mass. (Abstract shortened by UMI.)