Entelechy, citation indexes, and the association of ideas

Do you know what ‘entelechy’ means? It was in the title of a manuscript IJE received and it got me wondering what it meant and why the authors had used such an obscure word in their title. Indeed, one of our chosen reviewers (an eminent figure in gerontology) refused to read the manuscript as he did not understand the title. My more curious response was to look it up in the online Oxford Dictionary where all was revealed. Aristotle was the first to use the term as ‘the realization or complete expression of some function’, derived from the Greek meaning ‘to have perfection’. Catalano and Bruckner justify their use of entelechy as the most parsimonious means of communicating the idea of the effect of early-life adversities leading to failure of individuals or populations to achieve their expected lifespan. 1 Using cohort life table data from Sweden, Denmark, and England and Wales, they find support for the diminished entelechy hypothesis as the life expectancy of cohorts experiencing higher mortality below the age of 5 years was lower than expected. The effect seemed to be much weaker in women suggesting that they are more resilient than men to adversity, a point taken up by our commentators. 2 What does this add to our growing understanding of the early-life determinants of adult health? Will these relatively strong but non-specific signals marked by child mortality on late-life mortality make the detection of specific early-life exposures (e.g. diet, infections) operating at sensitive periods cumulatively more difficult given these pervasive general effects and the likely correlation between them and specific exposures? The impact factor for IJE has risen yet again and is now 4.045, double what it was when Davey Smith and I took over editorship of the journal. Is this a coincidence? We do not think so, but is it a marker of success? Our historic reprint is Eugene Garfield’s 1955 Science paper in which he first describes the rationale for developing a citation index and uses the term ‘impact factor’ for the first time, but, in reference to individual articles and not averaged over the output of a journal. 3 As Richard Smith, former editor of the British Medical Journal, points out, Garfield’s main perceived need for citation indexing was to avoid the ‘uncritical citation of fraudulent, incomplete or obsolete data’, but this problem remains despite the considerable power of the Web of Science to track citations. Garfield himself commenting here, also notes most scientists have yet to develop ‘citation consciousness’. 4 The law of unintended consequences might be invoked to explain the alacrity with which the impact factor has been seized up as a means of providing a number that can be used to ‘value’ the quality of a journal (and by extension, the quality of articles appearing in it). Porta et al. 5 provide insight into the numerator denominator bias involved in calculating the impact factor, the covert way in which these are defined journal by journal without any explicit criteria, and highlight the naı̈vety of using an arithmetic mean (to three decimal places) to compare highly skewed distributions of different journals (Figure 1). They conclude that it just is not scientific! So should we be happy with our rising impact factor? Porta et al. 5 suggest that total citations would be more relevant—but quarterly and bi-monthly journals will clearly publish fewer citable papers than weeklies. The sad fact is that a majority of papers published in medical journals are never cited at all, but whether we should read much into International Journal of Epidemiology’s rather better zero citation rate (about a quarter) compared with Lancet (just under half) and American Journal of Epidemiology (just over half) is debatable (Table 1). We consider our main editorial function is to make the International Journal of Epidemiology a journal that people want to pick up, dip into, and find at least one or two things that look interesting. Are we succeeding? Could we do better? A recent ‘citation classic’ of the International Journal of Epidemiology’s—anything with more than 50 cites is a classic for us—was a paper on sample sizes for cluster randomized trials. 6 In this issue, Eldridge et al. 7 tackle a very common problem for trialists doing cluster randomized trials—unequal cluster sizes that can lead to reduced power. They provide a simple formula for estimating sample size requirements, focusing on primary health care requirements although the methods have general applicability. Hopefully this will prove to be useful for trialists and give us another citation classic. One of Garfield’s purposes for citations was to provide an ‘association of ideas’ index, albeit not a substitute for extensive reading. The current obsession with ‘interdisciplinarity’ in research, particularly among funding agencies who want to shape the research landscape is all about the association of ideas. John Lynch gives his views on interdisciplinarity in 0 10 20 30 40 50 60