How reliable are standardised behaviour tests and are they valid in predicting the suitability for use in police horses?

Standardised behaviour tests have the potential to improve equine welfare by enabling the selection of horses suitable for a particular role. A range of tests are found in scientific literature which make such claims. However, with notable exceptions, authors have failed to establish the reliability of their tests or the validity of their claims. This study aimed to determine a set of reliable behaviour tests based on those reported in literature; and to test the validity of these as predictors of horses’ suitability as police horses. Reliability of response to a novel object, social isolation and handling tests was established by tests repeated at three week intervals on 33 horses. Behavioural responses were recorded post hoc to enable the full range of responses to be measured. There was some evidence that the horses habituated to static stimuli used in the tests, and the majority of the tests were at best moderately reliable, with only reactivity tests showing good or better reliability. Tests with moderately reliable results or results which could be explained by habituation, were included in the validity testing. This compared the horses’ responses to the behavioural tests with handlers’ ratings of key aspects of police horse performance. These subjective scales of suitability of police horses were developed from interviews with instructors and yard managers. The items were combined to develop a set of specific indices of police horse roles. Spearman’s rank order correlations were used to explore whether any relationships existed between the horses’ behavioural responses to the tests and subjective ratings of their suitability for their use. The results revealed eight moderate associations which were on the whole between horses’ responses to the reactivity tests (unexpected noise and sudden moving object) and the suitability scores. These findings suggest that standardised behavioural tests are not strongly reliable. The validity analysis indicated that either the tests used in this study did not serve as predictors of suitability for use, or that behavioural responses to standardised tests cannot be generalised to the wider challenges faced by these horses in their roles. However the reactivity tests did reveal stronger reliability and they were the only measures to show any association with the suitability scores, suggesting that reactivity tests may have some validity in measuring a horse’s suitability. Overall, the findings of this study cannot support claims made for these (or similar) tests to be valid predictors of a horse’s suitability for use

In-situ observations of volcanic ash clouds from the FAAM aircraft during the eruption of Eyjafjallajökull in 2010

During April–May 2010 the UK Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft flew 12 flights targeting volcanic ash clouds around the UK. The aircraft observed ash layers between altitudes of 2–8 km with peak mass concentrations typically between 200–2000 μg/m3, as estimated from a Cloud and Aerosol Spectrometer (CAS). A peak value of 2000–5000 μg/m3 was observed over Scotland on 14 May 2010, although with considerable uncertainty due to the possible contamination by ice. Aerosol size distributions within ash clouds showed a fine mode (0.1–0.6 μm) associated with sulphuric acid and/or sulphate, and a coarse mode (0.6–35 μm) associated with ash. The ash mass was dominated by particles in the size range 1–10 μm (volume-equivalent diameter), with a peak typically around 3–5 μm. Electron-microscope images and scattering patterns from the SID-2H (Small Ice Detector) probe showed the highly irregular shape of the ash particles. Ash clouds were also accompanied by elevated levels of SO2 (10–100 ppbv), strong aerosol scattering (50–500 × 10−6 m−1), and low Ångstrom exponents (−0.5 to 0.4) from the 3-wavelength nephelometer. Coarse-mode mass specific aerosol extinction coefficients (kext), based on the CAS size distribution varied from 0.45–1.06 m2/g. A representative value of 0.6 m2/g is suggested for distal ash clouds (∼1000 km downwind) from this eruption.Peer reviewe

The effectiveness and cost-effectiveness of diversion and aftercare programmes for offenders using class A drugs: a systematic review and economic evaluation

Background: The societal costs of problematic class A drug use in England and Wales exceed £15B; drug-related crime accounts for almost 90% of costs. Diversion plus treatment and/or aftercare programmes may reduce drug-related crime and costs. Objectives: To assess the effectiveness and cost-effectiveness of diversion and aftercare for class A drug-using offenders, compared with no diversion. Population: Adult class A drug-using offenders diverted to treatment or an aftercare programme for their drug use. Interventions: Programmes to identify and divert problematic drug users to treatment (voluntary, court mandated or monitored services) at any point within the criminal justice system (CJS). Aftercare follows diversion and treatment, excluding care following prison or non-diversionary drug treatment. Data sources: Thirty-three electronic databases and government online resources were searched for studies published between January 1985 and January 2012, including MEDLINE, PsycINFO and ISI Web of Science. Bibliographies of identified studies were screened. The UK Drug Data Warehouse, the UK Drug Treatment Outcomes Research Study and published statistics and reports provided data for the economic evaluation. Methods: Included studies evaluated diversion in adult class A drug-using offenders, in contact with the CJS. The main outcomes were drug use and offending behaviour, and these were pooled using meta-analysis. The economic review included full economic evaluations for adult opiate and/or crack, or powder, cocaine users. An economic decision analytic model, estimated incremental costs per unit of outcome gained by diversion and aftercare, over a 12-month time horizon. The perspectives included the CJS, NHS, social care providers and offenders. Probabilistic sensitivity analysis and one-way sensitivity analysis explored variance in parameter estimates, longer time horizons and structural uncertainty. Results: Sixteen studies met the effectiveness review inclusion criteria, characterised by poor methodological quality, with modest sample sizes, high attrition rates, retrospective data collection, limited follow-up, no random allocation and publication bias. Most study samples comprised US methamphetamine users. Limited meta-analysis was possible, indicating a potential small impact of diversion interventions on reducing drug use [odds ratio (OR) 1.68, 95% confidence interval (CI) 1.12 to 2.53 for reduced primary drug use, and OR 2.60, 95% CI 1.70 to 3.98 for reduced use of other drugs]. The cost-effectiveness review did not identify any relevant studies. The economic evaluation indicated high uncertainty because of variance in data estimates and limitations in the model design. The primary analysis was unclear whether or not diversion was cost-effective. The sensitivity analyses indicated some scenarios where diversion may be cost-effective. Limitations: Nearly all participants (99.6%) in the effectiveness review were American (Californian) methamphetamine users, limiting transfer of conclusions to the UK. Data and methodological limitations mean it is unclear whether or not diversion is effective or cost-effective. Conclusions: High-quality evidence for the effectiveness and cost-effectiveness of diversion schemes is sparse and does not relate to the UK. Importantly this research identified a range of methodological limitations in existing evidence. These highlight the need for research to conceptualise, define and develop models of diversion programmes and identify a core outcome set. A programme of feasibility, pilot and definitive trials, combined with process evaluation and qualitative research is recommended to assess the effectiveness and cost-effectiveness of diversionary interventions in class A drug-using offenders. Funding details: The National Institute for Health Research Health Technology Assessment programme