Problem-based learning for health improvement: practical public health for every professional

Statistical analysis on tiling array data is extremely challenging due to the astronomically large number of sequence probes, high noise levels of individual probes and limited number of replicates in these data. To overcome these difficulties, we first developed statistical error estimation and weighted ANOVA modeling approaches to high-density tiling array data, especially the former based on an advanced error-pooling method to accurately obtain heterogeneous technical error of small-sample tiling array data. Based on these approaches , we analyzed the high-density tiling array data of the temporal replication patterns during cell-cycle S phase of synchronized HeLa cells on human chromosomes 21 and 22. We found many novel temporal replication patterns, identifying about 26% of over 1 million tiling array sequence probes with significant differential replication during the four 2-h time periods of S phase. Among these differentially replicated probes, 126 941 sequence probes were matched to 417 known genes. The majority of these genes were found to be replicated within one or two consecutive time periods, while the others were replicated at two non-consecutive time periods. Also, coding regions found to be more differentially replicated in particular time periods than noncoding regions in the gene-poor chromosome 21 (25% differentially replicated among genic probes versus 18.6% among intergenic probes), while such a phenomenon was less prominent in gene-rich chromosome 22. A rigorous statistical testing for local proximity of differentially replicated genic and intergenic probes was performed to identify significant stretches of differentially replicated sequence regions. From this analysis, we found that adjacent genes were frequently replicated at different time periods, potentially implying the existence of quite dense replication origins. Evaluating the conditional probability significance of identified gene ontology terms on chromosomes 21 and 22, we detected some over-represented molecular functions and biological processes among these differentially replicated genes, such as the ones relevant to hydrolase, transferase and receptor-binding activities. Some of these results were confirmed showing 470% consistency with cDNA microarray data that were independently generated in parallel with the tiling arrays. Thus, our improved analysis approaches specifically designed for high-density tiling array data enabled us to reliably and sensitively identify many novel temporal replication patterns on human chromosomes.

The book is divided into ten chapters, each treating a different area of inquiry into the public health work in practice as outlined by the British Faculty of Public Health Medicine. The approach is pragmatic and behavioural throughout the book, every chapter contains illustrative examples that the authors comment in problem focusing discussions and methodological guidance. Every chapter is linked to the rest theoretically or practically. All chapters provide literature references and recommendations of further readings, including electronic links.
The focus in the book lies mainly on the art of negotiating and acquiring resources and less on resource reductions or unit closures. However, the need of priorities and changes is not omitted, at least on the project management level. A strong side of the book is that it considers both theory and practice of implementation of projects or programmes, the progress and success monitoring as well as the handover to the ordinary activity. On the other hand, quality improvement activities, as they also support health status improvement, should have been addressed as a matter of ongoing activity, not temporary and random projects as they still often are abroad.
The relevance of this book for integrated care is that it frequently points to partnership working, need of coordination and the central role of communication among individuals, teams, units and across agencies in all public health activities. The authors systematically address information needs of different stakeholders and the institutional level of the work with health status improvement of individual patients and populations, involving information and communication with media and policy makers.
Some weak sides of the book« The introduction states that the success of public health practice was the control of communicable diseases. It is true but the improvement began before many of the miracles of medicine emerged, mainly due to improved socioeconomic conditions of populations. The tubercle bacillus was identified in the 1880s. The decline in mortality from tuberculosis started decades before the development of treatment and preventive measures in the 1950s. Chapter 1 on surveillance and assessment of the population's health and wellbeing lacks some classic and recent references, in particular Modern Epidemiology by Roothman and Greenland (1998) and Systematic Reviews in Health Care by Egger et al. This book provides a superficial overview of research methods, contains inaccuracies on epidemiologic terms and methods and lacks a health care or health economics approach despite that the latter disciplines contribute to the evidence on effectiveness of health interventions and prioritisations.
The authors of chapter 9 confuse the concept of efficacy with the concept of effectiveness of therapies in a section on advantages and disadvantages of randomised controlled studies (RCT). A disadvantage of RCT is the problematic external validity due to the selection of younger, in most respects homogenous and healthier patients in experimental situations as opposite to observational studies, conducted in daily contexts, involving individuals with various origins, age and co-morbidities (Egger et al., Eds, 2001). Chapter 9 only mentions focus groups as an example of the qualitative approach and recommends odds ratios as a measure in retrospective case-control studies while relative risk is preferable.
The book deals with public health work as it mainly would an activity taking place in health care organisations. Interventions on policy levels to hinder dis-rupting effects of the environment on health status of populations such as distances, border crossing traffics, pollution are not illustrated. Such effects may be recognised in large epidemiological studies even if they are small and not easily discernible on the individual level. It would be a mistake if health professionals believed that they alone possess all the necessary measures and interventions to deal with the health of populations.
In summary, this book provides many useful solutions to crucial problems emerging in all work with individ-uals and smaller groups of people. It is a well written introduction for medical or public health students and less experienced practitioners on technical and operational levels in all health systems. It is less suitable for practitioners on institutional or international levels, for example at the European Union.