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Dive into the research topics where Billingsley Kaambwa is active.

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Featured researches published by Billingsley Kaambwa.


The Lancet | 2010

Telemonitoring and self-management in the control of hypertension (TASMINH2): a randomised controlled trial

Richard J McManus; Jonathan Mant; Ep Bray; R Holder; Miren I Jones; Sheila Greenfield; Billingsley Kaambwa; Miriam Banting; Stirling Bryan; Paul Little; Bryan Williams; Fd Richard Hobbs

BACKGROUND Control of blood pressure is a key component of cardiovascular disease prevention, but is difficult to achieve and until recently has been the sole preserve of health professionals. This study assessed whether self-management by people with poorly controlled hypertension resulted in better blood pressure control compared with usual care. METHODS This randomised controlled trial was undertaken in 24 general practices in the UK. Patients aged 35-85 years were eligible for enrolment if they had blood pressure more than 140/90 mm Hg despite antihypertensive treatment and were willing to self-manage their hypertension. Participants were randomly assigned in a 1:1 ratio to self-management, consisting of self-monitoring of blood pressure and self-titration of antihypertensive drugs, combined with telemonitoring of home blood pressure measurements or to usual care. Randomisation was done by use of a central web-based system and was stratified by general practice with minimisation for sex, baseline systolic blood pressure, and presence or absence of diabetes or chronic kidney disease. Neither participants nor investigators were masked to group assignment. The primary endpoint was change in mean systolic blood pressure between baseline and each follow-up point (6 months and 12 months). All randomised patients who attended follow-up visits at 6 months and 12 months and had complete data for the primary outcome were included in the analysis, without imputation for missing data. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN17585681. FINDINGS 527 participants were randomly assigned to self-management (n=263) or control (n=264), of whom 480 (91%; self-management, n=234; control, n=246) were included in the primary analysis. Mean systolic blood pressure decreased by 12.9 mm Hg (95% CI 10.4-15.5) from baseline to 6 months in the self-management group and by 9.2 mm Hg (6.7-11.8) in the control group (difference between groups 3.7 mm Hg, 0.8-6.6; p=0.013). From baseline to 12 months, systolic blood pressure decreased by 17.6 mm Hg (14.9-20.3) in the self-management group and by 12.2 mm Hg (9.5-14.9) in the control group (difference between groups 5.4 mm Hg, 2.4-8.5; p=0.0004). Frequency of most side-effects did not differ between groups, apart from leg swelling (self-management, 74 patients [32%]; control, 55 patients [22%]; p=0.022). INTERPRETATION Self-management of hypertension in combination with telemonitoring of blood pressure measurements represents an important new addition to control of hypertension in primary care. FUNDING Department of Health Policy Research Programme, National Coordinating Centre for Research Capacity Development, and Midlands Research Practices Consortium.


Health Technology Assessment | 2013

A systematic review and economic evaluation of subcutaneous and sublingual allergen immunotherapy in adults and children with seasonal allergic rhinitis

Angela Meadows; Billingsley Kaambwa; Nicola Novielli; Aarnoud Huissoon; A Fry-Smith; Catherine Meads; Pelham Barton; Janine Dretzke

BACKGROUND Severe allergic rhinitis uncontrolled by conventional medication can substantially affect quality of life. Immunotherapy involves administering increasing doses of a specific allergen, with the aim of reducing sensitivity and symptomatic reactions. Recent meta-analyses have concluded that both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are more effective than placebo in reducing symptoms. It is uncertain which route of administration is more effective and whether or not treatment is cost-effective. OBJECTIVE To determine the comparative clinical effectiveness and cost-effectiveness of SCIT and SLIT for seasonal allergic rhinitis in adults and children. DATA SOURCES Electronic databases {MEDLINE, EMBASE, The Cochrane Library [Cochrane Central Register of Controlled Trials (CENTRAL)], NHS Economic Evaluation Database (NHS EED)} and trial registries (from inception up to April 2011). REVIEW METHODS Standard systematic review methods were used for study selection, data extraction and quality assessment. Double-blind randomised, placebo-controlled trials of SCIT or SLIT, or of SCIT compared with SLIT, and economic evaluations were included. Meta-analysis and indirect comparison meta-analysis and meta-regression were carried out. A new economic model was constructed to estimate cost-utility. RESULTS Meta-analyses found statistically significant effects for SCIT and SLIT compared with placebo across a number of outcome measures and for the vast majority of subgroup analyses (type and amount of allergen, duration of treatment). There was less evidence for children, but some results in favour of SLIT were statistically significant. Indirect comparisons did not provide conclusive results in favour of either SCIT or SLIT. Economic modelling suggested that, when compared with symptomatic treatment (ST), both SCIT and SLIT may become cost-effective at a threshold of £20,000-30,000 per quality-adjusted life-year (QALY) from around 6 years, or 5 years for SCIT compared with SLIT (NHS and patient perspective). LIMITATIONS It is uncertain to what extent changes in the outcome measures used in the trials translate into clinically meaningful benefits. Cost-effectiveness estimates are based on a simple model, limited data and a number of assumptions, and should be seen as indicative only. CONCLUSIONS A benefit from both SCIT and SLIT compared with placebo has been consistently demonstrated, but the extent of this effectiveness in terms of clinical benefit is unclear. Both SCIT and SLIT may be cost-effective compared with ST from around 6 years (threshold of £20,000-30,000 per QALY). Further research is needed to establish the comparative effectiveness of SCIT compared with SLIT and to provide more robust cost-effectiveness estimates. FUNDING The National Institute for Health Research Health Technology Assessment programme.


European Journal of Preventive Cardiology | 2014

Telemonitoring and self-management in the control of hypertension (TASMINH2): a cost-effectiveness analysis.

Billingsley Kaambwa; Stirling Bryan; Sue Jowett; Jonathan Mant; Emma P Bray; Fd Richard Hobbs; Roger Holder; Miren I Jones; Paul Little; Bryan Williams; Richard J McManus

Aims: Self-monitoring and self-titration of antihypertensives (self-management) is a novel intervention which improves blood pressure control. However, little evidence exists regarding the cost-effectiveness of self-monitoring of blood pressure in general and self-management in particular. This study aimed to evaluate whether self-management of hypertension was cost-effective. Design and methods: A cohort Markov model-based probabilistic cost-effectiveness analysis was undertaken extrapolating to up to 35 years from cost and outcome data collected from the telemonitoring and self-management in hypertension trial (TASMINH2). Self-management of hypertension was compared with usual care in terms of lifetime costs, quality adjusted life years and cost-effectiveness using a UK Health Service perspective. Sensitivity analyses examined the effect of different time horizons and reduced effectiveness over time from self-management. Results: In the long-term, when compared with usual care, self-management was more effective by 0.24 and 0.12 quality adjusted life years (QALYs) gained per patient for men and women, respectively. The resultant incremental cost-effectiveness ratio for self-management was £1624 per QALY for men and £4923 per QALY for women. There was at least a 99% chance of the intervention being cost-effective for both sexes at a willingness to pay threshold of £20,000 per QALY gained. These results were robust to sensitivity analyses around the assumptions made, provided that the effects of self-management lasted at least two years for men and five years for women. Conclusion: Self-monitoring with self-titration of antihypertensives and telemonitoring of blood pressure measurements not only reduces blood pressure, compared with usual care, but also represents a cost-effective use of health care resources.


European Journal of Health Economics | 2013

Mapping utility scores from the Barthel index

Billingsley Kaambwa; Lucinda Billingham; Stirling Bryan

PurposeIt is not always possible to collect utility-based outcome data, like EQ-5D, needed for conducting economic evaluations in populations of older people. Sometimes, information on other non-utility outcome measures may have been collected. This paper examines the possibility of mapping the EQ-5D from a non-utility-based outcome, the Barthel index.MethodsData for 1,189 UK intermediate care patients were used. Ordinary least squares (OLS), censored least absolute deviations (CLAD) estimator and multinomial logistic (ML) models were used. The mean absolute error (MAE) and root-mean-squared error (RMSE) were used to estimate the predictive accuracy of eight regression models. Validation of primary models was carried out on random samples of data collected at admission and discharge.ResultsModels where the EQ-5D was entered as a continuous dependent variable and Barthel dimensions used as explanatory variables performed better. CLAD performed best on MAE and OLS on the RMSE, while the ML performed the worst on both measures. The CLAD predicted EQ-5D scores that matched the observed values more closely than the OLS.ConclusionsIt is possible to reasonably predict that the EQ-5D from the Barthel using regression methods and the CLAD model (4) is recommended.


British Journal of Obstetrics and Gynaecology | 2010

Cost‐effectiveness of rapid tests and other existing strategies for screening and management of early‐onset group B streptococcus during labour

Billingsley Kaambwa; Stirling Bryan; J. Gray; P. Milner; Jane P Daniels; Khalid S. Khan; Tracy E Roberts

Please cite this paper as: Kaambwa B, Bryan S, Gray J, Milner P, Daniels J, Khan K, Roberts T. Cost‐effectiveness of rapid tests and other existing strategies for screening and management of early‐onset group B streptococcus during labour. BJOG 2010;117:1616–1627.


BMC Research Notes | 2012

Do the methods used to analyse missing data really matter? An examination of data from an observational study of Intermediate Care patients

Billingsley Kaambwa; Stirling Bryan; Lucinda Billingham

BackgroundMissing data is a common statistical problem in healthcare datasets from populations of older people. Some argue that arbitrarily assuming the mechanism responsible for the missingness and therefore the method for dealing with this missingness is not the best option—but is this always true? This paper explores what happens when extra information that suggests that a particular mechanism is responsible for missing data is disregarded and methods for dealing with the missing data are chosen arbitrarily.Regression models based on 2,533 intermediate care (IC) patients from the largest evaluation of IC done and published in the UK to date were used to explain variation in costs, EQ-5D and Barthel index. Three methods for dealing with missingness were utilised, each assuming a different mechanism as being responsible for the missing data: complete case analysis (assuming missing completely at random—MCAR), multiple imputation (assuming missing at random—MAR) and Heckman selection model (assuming missing not at random—MNAR). Differences in results were gauged by examining the signs of coefficients as well as the sizes of both coefficients and associated standard errors.ResultsExtra information strongly suggested that missing cost data were MCAR. The results show that MCAR and MAR-based methods yielded similar results with sizes of most coefficients and standard errors differing by less than 3.4% while those based on MNAR-methods were statistically different (up to 730% bigger). Significant variables in all regression models also had the same direction of influence on costs. All three mechanisms of missingness were shown to be potential causes of the missing EQ-5D and Barthel data. The method chosen to deal with missing data did not seem to have any significant effect on the results for these data as they led to broadly similar conclusions with sizes of coefficients and standard errors differing by less than 54% and 322%, respectively.ConclusionsArbitrary selection of methods to deal with missing data should be avoided. Using extra information gathered during the data collection exercise about the cause of missingness to guide this selection would be more appropriate.


BMC Cardiovascular Disorders | 2013

Targets and self-management for the control of blood pressure in stroke and at risk groups (TASMIN-SR): protocol for a randomised controlled trial

Claire O’Brien; Emma P Bray; Stirling Bryan; Sheila Greenfield; M Sayeed Haque; Fd Richard Hobbs; Miren I Jones; Sue Jowett; Billingsley Kaambwa; Paul Little; Jonathan Mant; Cristina Penaloza; Claire Schwartz; Helen Shackleford; Jinu Varghese; Bryan Williams; Richard J McManus

BackgroundSelf-monitoring of hypertension with self-titration of antihypertensives (self-management) results in lower systolic blood pressure for at least one year. However, few people in high risk groups have been evaluated to date and previous work suggests a smaller effect size in these groups. This trial therefore aims to assess the added value of self-management in high risk groups over and above usual care.Methods/DesignThe targets and self-management for the control of blood pressure in stroke and at risk groups (TASMIN-SR) trial will be a pragmatic primary care based, unblinded, randomised controlled trial of self-management of blood pressure (BP) compared to usual care. Eligible patients will have a history of stroke, coronary heart disease, diabetes or chronic kidney disease and will be recruited from primary care. Participants will be individually randomised to either usual care or self-management. The primary outcome of the trial will be difference in office SBP between intervention and control groups at 12 months adjusted for baseline SBP and covariates. 540 patients will be sufficient to detect a difference in SBP between self-management and usual care of 5 mmHg with 90% power. Secondary outcomes will include self-efficacy, lifestyle behaviours, health-related quality of life and adverse events. An economic analysis will consider both within trial costs and a model extrapolating the results thereafter. A qualitative analysis will gain insights into patients’ views, experiences and decision making processes.DiscussionThe results of the trial will be directly applicable to primary care in the UK. If successful, self-management of blood pressure in people with stroke and other high risk conditions would be applicable to many hundreds of thousands of individuals in the UK and beyond.Trial RegistrationISRCTN87171227


Journal of Telemedicine and Telecare | 2017

Investigating the preferences of older people for telehealth as a new model of health care service delivery: A discrete choice experiment.

Billingsley Kaambwa; Julie Ratcliffe; Wendy Shulver; Maggie Killington; Alan Taylor; Maria Crotty; Colin J. Carati; Jennifer Tieman; Victoria Wade; Michael Kidd

Introduction Telehealth approaches to health care delivery can potentially improve quality of care and clinical outcomes, reduce mortality and hospital utilisation, and complement conventional treatments. However, substantial research into the potential for integrating telehealth within health care in Australia, particularly in the provision of services relevant to older people, including palliative care, aged care and rehabilitation, is lacking. Furthermore, to date, no discrete choice experiment (DCE) studies internationally have sought the views and preferences of older people about the basic features that should make up a telehealth approach to these services. Methods Using a DCE, we investigated the relative importance of six salient features of telehealth (what aspects of care are to be pursued during telehealth sessions, distance to the nearest hospital or clinic, clinicians’ attitude to telehealth, patients’ experience of using technology, what types of assessments should be conducted face-to-face versus via telehealth sessions and the costs associated with receiving telehealth). Data were obtained from an online panel of older people aged 65 years and above, drawn from the Australian general population. Results The mean age for 330 study participants was 69 years. In general, individuals expressed strong preferences for telehealth services that offered all aspects of care, were relatively inexpensive and targeted specifically at individuals living in remote regions without easy access to a hospital or clinic. Participants also preferred telehealth services to be offered to individuals with some prior experience of using technology, provided by clinicians who were positive about telehealth but wanted all or some pre-telehealth health assessments to take place in a hospital or clinic. Preferences only differed by gender. Additionally, respondents did not feel that telehealth led to loss of privacy and confidentiality. Discussion Our findings indicate a preference amongst respondents for face-to-face pre-telehealth health assessments and, thereafter, a comprehensive telehealth model (in terms of services offered) targeted at those with some technological know-how as a substitute for attendance at hospitals and clinics, especially where these health facilities were far away from older people’s homes. The findings may be usefully incorporated into the design of future telehealth models of service delivery for older people.


Health & Social Care in The Community | 2017

Consumer Directed Care in Australia: early perceptions and experiences of staff, clients and carers

Liz Gill; Nikki McCaffrey; Ian D. Cameron; Julie Ratcliffe; Billingsley Kaambwa; Megan Corlis; Jeff Fiebig; Meredith Gresham

The study aimed to identify the shared issues and challenges being experienced by staff, their clients and informal carers, with the introduction of Consumer Directed Care (CDC). Secondary analysis was undertaken of data that had been initially collected, via semi-structured in-depth interviews, to inform the development of a discrete choice experiment. The raw staff and client/carer data were re-examined using an iterative inductive process. The analysis focused on locating the shared themes and differences between the participant groups based on their CDC experience. The data were also assessed for difficulties or barriers that impacted on the service. Four broad shared themes were derived: culture, role change, operational systems and resourcing, but with a range of diverse and sometimes conflicting sub-themes between the different participant groups. Differences can be linked to participant role in the service chain, with discordance emerging between what has been traditionally offered and what might be possible. This investigation occurred during the period in which services were transitioning from a traditional aged care service model to a new model of service provision requiring considerable industry change. We conclude that existing industry regulation, culture and practice supports an established service model in Australia that arguably makes translation of the objectives of CDC difficult.


Rheumatology | 2015

Economic evaluation of a brief Education, Self-management and Upper Limb Exercise Training in People with Rheumatoid Arthritis (EXTRA) programme: a trial-based analysis.

Victoria Manning; Billingsley Kaambwa; Julie Ratcliffe; David Scott; Ernest Choy; Michael Hurley; Lindsay Bearne

OBJECTIVE The aim of this study was to conduct a cost-utility analysis of the Education, Self-management and Upper Limb Exercise Training in People with RA (EXTRA) programme compared with usual care. METHODS A within-trial incremental cost-utility analysis was conducted with 108 participants randomized to either the EXTRA programme (n = 52) or usual care (n = 56). A health care perspective was assumed for the primary analysis with a 36 week follow-up. Resource use information was collected on interventions, medication, primary and secondary care contacts, private health care and social care costs. Quality-adjusted life years (QALYs) were calculated from the EuroQol five-dimension three-level (EQ-5D-3L) questionnaire responses at baseline, 12 and 36 weeks. RESULTS Compared with usual care, total QALYs gained were higher in the EXTRA programme, leading to an increase of 0.0296 QALYs. The mean National Health Service (NHS) costs per participant were slightly higher in the EXTRA programme (by £82), resulting in an incremental cost-effectiveness ratio of £2770 per additional QALY gained. Thus the EXTRA programme was cost effective from an NHS perspective when assessed against the threshold of £20 000-£30 000/QALY gained. Overall, costs were lower in the EXTRA programme compared with usual care, suggesting it was the dominant treatment option from a societal perspective. At a willingness-to-pay of £20 000/QALY gained, there was a 65% probability that the EXTRA programme was the most cost-effective option. These results were robust to sensitivity analyses accounting for missing data, changing the cost perspective and removing cost outliers. CONCLUSION The physiotherapist-led EXTRA programme represents a cost-effective use of resources compared with usual care and leads to lower health care costs and work absence. TRIAL REGISTRATION International Standard Randomized Controlled Trial Number Register; http://www.controlled-trials.com/isrctn/ (ISRCTN14268051).

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Julie Ratcliffe

University of South Australia

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Stirling Bryan

University of British Columbia

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Bryan Williams

University College London

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Miren I Jones

University of Birmingham

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Paul Little

University of Southampton

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