Cost-effectiveness of financial incentives for smoking cessation in pregnancy

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The generation of tsunamis

Tsunamis are gravity-driven water waves. Most are generated by vertical displacement of the seabed that propagates through the water column to the sea surface. The resulting elevated surface wave collapses through gravity and then propagates outward from the source. Dispersion of the initial wave generates a multiple wave train. Tsunamis are mainly (∼80%) generated by earthquakes, but other mechanisms include subaerial and submarine landslides and volcanic collapse and eruption. Other, less frequent, tsunami mechanisms include bolide (asteroid) impact and weather events (meteotsunamis), but these are generated at the water surface, respectively, from external impact and from wind friction. The magnitude of a tsunamigenic earthquake has the main control on the tsunami, although “tsunami” earthquakes generate tsunamis much larger than expected from their earthquake source magnitude. Tsunamigenic earthquake mechanisms include interplate boundary rupture, splay faulting, and intraplate rupture. Landslide tsunami mechanisms include slumps and translational failures that may be initiated from either the bottom or the top. Landslide volume, water depth, and initial acceleration are the main controls on tsunami magnitude, although other factors such as the failure mechanism and the location of initiation are influential. There are three main aspects of a tsunami; (i) initial wave generation, (ii) propagation, and (iii) onland run-up. Initial wave generation from earthquakes is mainly from seabed vertical displacement, and a rule of thumb suggests that in most instances the maximum initial wave elevation is up to twice this. The maximum initial wave elevation from a landslide tsunami is theoretically determined by the ocean depth and thus could be thousands of meters. Local tsunami run-up elevations vary with source mechanism and vary considerably. Although dependent on local bathymetry and topography, these are likely to be more elevated and focused from submarine landslides than from earthquakes. The different mechanisms generate different tsunami wave frequencies; these determine travel distances, with the low frequency tsunamis from earthquakes traveling much farther than tsunamis from landslides, which are much higher frequency. Final onland run-up is mainly dependent on source mechanism as well as local offshore bathymetry and coastal topography

The importance of geologists and geology in tsunami science and tsunami hazard

Up until the late 1980s geology contributed very little to the study of tsunamis because most were generated by earthquakes which were mainly the domain of seismologists. In 1987–88 however, sediments deposited as tsunamis flooded land were discovered. Subsequently they began to be widely used to identify prehistorical tsunami events, providing a longer-term record than previously available from historical accounts. The sediments offered an opportunity to better define tsunami frequency that could underpin improved risk assessment. When over 2200 people died from a catastrophic tsunami in Papua New Guinea (PNG) in 1998, and a submarine landslide was controversially proven to be the mechanism, marine geologists provided the leadership that led to the identification of this previously unrecognized danger. The catastrophic tsunami in the Indian Ocean in 2004 confirmed the critical importance of sedimentological research in understanding tsunamis. In 2011, the Japan earthquake and tsunami further confirmed the importance of both sediments in tsunami hazard mitigation and the dangers from seabed sediment failures in tsunami generation. Here we recount the history of geological involvement in tsunami science and its importance in advancing understanding of the extent, magnitude and nature of the hazard from tsunamis

Challenging the view that lack of fibre causes childhood constipation

Objectives: To assess evidence supporting the view that ‘low fibre causes childhood constipation’. Design: Triangulation integrated three approaches: a systematic review NICE guideline CG99 examining effectiveness of increasing fibre; a cohort study, Avon Longitudinal Study of Parents and Children (ALSPAC), to assess if constipation (or hard stools) can precede fibre intake at weaning; and a literature search for twin studies to calculate heredity. Setting: CG99 examined the literature regarding the effectiveness of increasing fibre. ALSPAC asked parents about: hard stools at 4 weeks, 6 months and 2.5 years and constipation at age 4–10 years, as well as fibre intake at 2 years. Twin studies and data from ALSPAC were pooled to calculate concordance of constipation comparing monozygotic and dizygous twin pairs. Participants: CG99 reported six randomised controlled trials (RCTs). ALSPAC hard stool data from 6796 children at 4 weeks, 9828 at 6 months and 9452 at 2.5 years plus constipation data on 8401 at 4–10 years were compared with fibre intake at 2 years. Twin studies had 338 and 93 twin pairs and ALSPAC added a further 45. Results: Increasing fibre did not effectively treat constipation. Hard stools at 4 weeks predated fibre and at 6 months predicted lower fibre intake at 2 years (p=0.003). Heredity explained 59% of constipation. Conclusions: RCTs indicate that increasing fibre is not an effective treatment for constipation in children. Hard stools can precede and predict later fibre intake. Genetic inheritance explains most childhood constipation. Extended treatment with stool softeners may improve fibre intake and limit long-term damaging sequelae of constipation

Are financial incentives cost-effective to support smoking cessation during pregnancy?

Aims  To investigate the cost-effectiveness of up to £400 worth of financial incentives for smoking cessation in pregnancy as an adjunct to routine health care.  Design  Cost-effectiveness analysis based on a Phase II randomized controlled trial (RCT) and a cost–utility analysis using a life-time Markov model.  Setting  The RCT was undertaken in Glasgow, Scotland. The economic analysis was undertaken from the UK National Health Service (NHS) perspective.  Participants  A total of 612 pregnant women randomized to receive usual cessation support plus or minus financial incentives of up to £400 vouchers (US 609), contingent upon smoking cessation.  Measurements  Comparison of usual support and incentive interventions in terms of cotinine-validated quitters, quality-adjusted life years (QALYs) and direct costs to the NHS.  Findings  The incremental cost per quitter at 34–38 weeks pregnant was £1127 (1716).This is similar to the standard look-up value derived from Stapleton & West's published ICER tables, £1390 per quitter, by looking up the Cessation in Pregnancy Incentives Trial (CIPT) incremental cost (£157) and incremental 6-month quit outcome (0.14). The life-time model resulted in an incremental cost of £17 [95% confidence interval (CI) = –£93, £107] and a gain of 0.04 QALYs (95% CI = –0.058, 0.145), giving an ICER of £482/QALY ($734/QALY). Probabilistic sensitivity analysis indicates uncertainty in these results, particularly regarding relapse after birth. The expected value of perfect information was £30 million (at a willingness to pay of £30 000/QALY), so given current uncertainty, additional research is potentially worthwhile.  Conclusion  Financial incentives for smoking cessation in pregnancy are highly cost-effective, with an incremental cost per quality-adjusted life years of £482, which is well below recommended decision thresholds

Effectiveness of policy to provide breastfeeding groups (BIG) for pregnant and breastfeeding mothers in primary care: cluster randomised controlled trial

Objective To assess the clinical effectiveness and cost effectiveness of a policy to provide breastfeeding groups for pregnant and breastfeeding women

Reliability of self reported smoking status by pregnant women for estimating smoking prevalence: a retrospective, cross sectional study

Objective To determine what impact reliance on self reported smoking status during pregnancy has on both the accuracy of smoking prevalence figures and access to smoking cessation services for pregnant women in Scotland

Tsunamis: geology, hazards and risks: introduction

A decade or so ago, if you had asked almost anyone in Europe or North America, they might not have recognized the word ‘tsunami’. The enormous and tragic event that swept across the shores of the Indian Ocean on 26 December 2004, followed only a few years later by the devastating tsunami caused by the March 2011 Great Tohoku earthquake off Japan, both with appalling loss of life, changed all that. Today, the words ‘tsunami warning issued’ seem to appear frequently on international ‘breaking news’, showing the extent to which we have become sensitized to the triggers that launch these deadly, but terrifyingly spectacular, natural events. Yet, great tsunamis and the tectonic events that cause them have not suddenly become more frequent. The historical records of old civilizations contain accounts of major inundations reaching back hundreds or thousands of years and sometimes even warnings to future generations – valuable, if they are heeded. What has changed, and has consequently raised the profile of tsunamis, is the exponential growth in world population over the last few 100 years, the great majority of whom live in coastal areas and are consequently exposed to hazard, along with instant global communication, which brings every large earthquake on Earth's plate margins directly and immediately onto our screens