Committee experiences of using formal consensus in healthcare guidelines: a longitudinal qualitative study.

BACKGROUND: This feasibility study has the primary aim of capturing and comparing participant expectations and experiences of using a formal consensus method (FCM) and to explore whether these views change following participation within a guideline committee where FCM are used. METHODS: Twelve healthcare committee members and associated technical team members participated in semi-structured qualitative interviews before and after using FCM during guideline committee meetings. Interviews also focused on past experiences and expectations of informal consensus methods. RESULTS: Participants said formal consensus included a greater range of evidence. They described positive reactions and found it a useful way to encourage involvement by balancing group power dynamics. Group discussion time was identified as important to clarify ideas, supported by good group chairing. However, participants reported that undertaking FCM required additional resources and suggested targeting its use for low quality evidence, limited committee expertise, or where the evidence is controversial. CONCLUSIONS: FCM is an acceptable alternative to informal consensus methods that has qualities specifically helpful to healthcare guidelines such as encouraging participation, inclusivity of a broad range of evidence, and managing group dynamics. More research is required to better understand when using formal consensus is most appropriate and effective.

A demonstration of using formal consensus methods within guideline development; a case study.

BACKGROUND: Recommendations within guidelines are developed by synthesising the best available evidence; when limited evidence is identified recommendations are generally based on informal consensus. However, there are potential biases in group decision making, and formal consensus methods may help reduce these. METHODS: We conducted a case study using formal consensus, to develop one set of recommendations within the Neonatal Parenteral Nutrition guideline being produced for the National Institute for Health and Care Excellence. Statements were generated through identification of published guidelines on several topics relating to neonatal parenteral nutrition. Ten high quality guidelines were included, and 28 statements were generated; these statements were rated by the committee via two rounds of voting. The statements which resulted in agreement were then used to develop the recommendations. RESULTS: The approach was systematic and provided transparency. Additionally, a number of lessons were learnt; including the value of selecting the appropriate topic, giving adequate time to the process, and ensuring methodologies are understood by the committee for their value and relevance. CONCLUSION: Formal consensus is a valuable option for use within guideline development when specific criteria are met. The approach provides transparent methodology, ensuring clarity on how recommendations are developed.

Screening for gestational diabetes mellitus: cost-utility of different screening strategies based on a woman's individual risk of disease.

AIMS/HYPOTHESIS: The cost-effectiveness of eight strategies for screening for gestational diabetes (including no screening) was estimated with respect to the level of individual patient risk. METHODS: Cost-utility analysis using a decision analytic model populated with efficacy evidence pooled from recent randomised controlled trials, from the funding perspective of the National Health Service in England and Wales. Seven screening strategies using various combinations of screening and diagnostic tests were tested in addition to no screening. The primary outcome measure was the incremental cost per quality-adjusted life-year (QALY) over a lifetime. RESULTS: The strategy that has the greatest likelihood of being cost-effective is dependent on the risk of gestational diabetes mellitus for each individual woman. When gestational diabetes mellitus risk is <1% then the no screening/treatment strategy is cost-effective; where risk is between 1.0% and 4.2% fasting plasma glucose followed by OGTT is most likely to be cost-effective; and where risk is >4.2%, universal OGTT is most likely to be cost-effective. However, acceptability of the test alters the most cost-effective strategy. CONCLUSIONS/INTERPRETATION: Screening for gestational diabetes can be cost-effective. The best strategy is dependent on the underlying risk of each individual and the acceptability of the tests used. The current study suggests that if a woman's individual risk of gestational diabetes could be accurately predicted, then healthcare resource allocation could be improved by providing an individualised screening strategy.

Setting microbiological water quality standards for sea bathing--a critical evaluation.

The World Health Organization (WHO) recently produced draft guidelines for safe recreational water environments. The microbiological standards proposed in the guidelines are expected to overestimate the degree of water quality required to provide given levels of public health protection. The WHO standards were obtained by means of a risk assessment which featured a dose-response model derived from a series of randomised controlled trials. The trials have many strengths but biases and problems with statistical analysis are likely to have led to over-estimation of the risks from bathing in the dose-response model. In addition, the WHO risk assessment failed to consider the effects of uncertainty and variability in risk estimates and sensitivity to model assumptions. Improved standards could be obtained by extending the risk assessment to examine these effects and by incorporating a suitably revised dose-response model.

Hyperplastic and Neoplastic Changes in the Lungs of Rats Treated Concurrently with Chrysotile Asbestos and N-Nitrosoheptamethyleneimine.

This study investigated the combined effect in rat lungs of simultaneous exposure to chrysotile asbestos and N-nitrosoheptamethyleneimine (NHMI), with the objective of determining the potential for chrysotile to promote or otherwise enhance the pathological responses to this potent rodent lung carcinogen. Groups of 15 or 20 male and female animals were treated with 0, 3, or 10 mg kg(-1) NHMI subcutaneously, once a week for 10 wk, plus either clean air (control) or 50 mg m(-3) chrysotile by nose-only inhalation for 4 wk. A broad range of pulmonary metaplastic, hyperplastic, and neoplastic lesions was observed. Effects were more marked in male than in female animals. NHMI treatment increased the incidence of hyperplastic lesions, with apparent augmentation by chrysotile exposure (not statistically significant). Similarly, a "promoting" effect of chrysotile in the induction of lung tumors was observed, with all but 2 of the 11 primary tumors detected being in animals treated with both NHMI and asbestos. However, this apparent interaction was again not confirmable statistically, probably because of the low number of observed tumors (stemming from premature termination of the experiment). The study results are in line with those of similar previous studies, which found a higher incidence of hyperplastic and neoplastic changes in animals treated with both nitrosamine and asbestos than in those given nitrosamine alone. It is proposed that the method described (with minor modification) could be used to investigate either (1) the ability of other inhaled particles to augment NHMI carcinogenicity, or (2) the propensity of other chemical carcinogens to interact with asbestos in the production of pulmonary neoplasms.

Effects of gibberellin A(4 + 7) and bark-ringing on cone initiation in mature Picea sitchensis grafts.

Large numbers of cones (strobili) were induced in a 10-year-old plot of mature grafts of Picea sitchensis (Bong.) Carr. All trees injected with 20 mg GA(4 + 7) in June initiated female and male cones in the same year. This treatment increased the number of female cones per plant 12-fold above the controls, more than doubling the percentage of cones that were female. Complete bark-ringing (done in May of the previous year) showed an additive effect with GA on the number of female cones formed, but a negative interaction on the number of male cones induced. Ringing promoted male cone production most when used alone. Treatments, singly or combined, also increased the proportion of cones that were lateral, compared with the preponderance of terminal male cones in the controls. The effects were apparently not directly associated with alterations in vegetative vigor, although these occurred causing a reduction in the proportion of buds containing vegetative shoots the following year. The clones differed in most characteristics, but both sparse and prolific clones were induced to reproductive activity. Viable seed yields per tree, and notional production from seed-orchards were enhanced almost 10-fold by GA injection, and about 4-fold by bark-ringing and GA + bark-ringing.