Browsing by Author "Kilonzo, Mary Mueni"

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A cost-utility analysis of multivitamin and multimineral supplements in men and women aged 65 years and over
(Elsevier, 2007) Kilonzo, Mary Mueni; Vale, Luke David; Cook, Jonathan Alistair; Milne, Anne Catherine; Stephen, Audrey Isabella; Avenell, Alison; MAVIS Trial Group; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Background and Aims As people age there is a progressive dysregulation of the immune system that may lead to an increased risk of infections, which may precipitate hospital admission in people with chronic heart or respiratory diseases. Mineral and vitamin supplementation in older people could therefore influence infections in older people. However, the evidence from the available randomised controlled trials is mixed. The aim of the study was to assess the relative efficiency of multivitamin and multimineral supplementation compared with no supplementation. Methods Cost-utility analysis alongside a randomised controlled trial. Participants aged 65 years or over from six general practices in Grampian, Scotland were studied. They were randomised to one tablet daily of either a multivitamin and multimineral supplement or matching placebo. Exclusion criteria were: use of mineral, vitamin or fish oil supplements in the previous three months (one month for water soluble vitamins), vitamin B12 injection in the last three months. Results Nine hundred and ten participants were recruited (454 placebo and 456 supplementation). Use of health service resources and costs were similar between the two groups. The supplementation arm was more costly although this was not statistically significant (£15 per person, 95% CI -3.75 to 34.95). After adjusting for minimisation and baseline EQ-5D scores supplementation was associated with fewer QALYs per person (–0.018, 95% CI -0.04 to 0.002). It was highly unlikely that supplementation would be considered cost-effective. Conclusions The evidence from this study suggests that it is highly unlikely that supplementation could be considered cost-effective.
Effect of multivitamin and multimineral supplementation on cognitive function in men and women aged 65 years and over : a randomised controlled trial
(BMC, 2007-05-02) McNeil, Geraldine; Avenell, Alison; Campbell, Marion Kay; Cook, Jonathan Alistair; Hannaford, Philip Christopher; Kilonzo, Mary Mueni; Milne, Anne Catherine; Ramsay, Craig R; Seymour, David Gwyn; Stephen, Audrey Isabella; Vale, Luke David; MAVIS Trial Group; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Background: Observational studies have frequently reported an association between cognitive function and nutrition in later life but randomised trials of B vitamins and antioxidant supplements have mostly found no beneficial effect. We examined the effect of daily supplementation with 11 vitamins and 5 minerals on cognitive function in older adults to assess the possibility that this could help to prevent cognitive decline. Methods: The study was carried out as part of a randomised double blind placebo controlled trial of micronutrient supplementation based in six primary care health centres in North East Scotland. 910 men and women aged 65 years and over living in the community were recruited and randomised: 456 to active treatment and 454 to placebo. The active treatment consisted of a single tablet containing eleven vitamins and five minerals in amounts ranging from 50–210 % of the UK Reference Nutrient Intake or matching placebo tablet taken daily for 12 months. Digit span forward and verbal fluency tests, which assess immediate memory and executive functioning respectively, were conducted at the start and end of the intervention period. Risk of micronutrient deficiency at baseline was assessed by a simple risk questionnaire. Results: For digit span forward there was no evidence of an effect of supplements in all participants or in sub-groups defined by age or risk of deficiency. For verbal fluency there was no evidence of a beneficial effect in the whole study population but there was weak evidence for a beneficial effect of supplementation in the two pre-specified subgroups: in those aged 75 years and over (n 290; mean difference between supplemented and placebo groups 2.8 (95% CI -0.6, 6.2) units) and in those at increased risk of micronutrient deficiency assessed by the risk questionnaire (n 260; mean difference between supplemented and placebo groups 2.5 (95% CI -1.0, 6.1) units). Conclusion: The results provide no evidence for a beneficial effect of daily multivitamin and multimineral supplements on these domains of cognitive function in community-living people over 65 years. However, the possibility of beneficial effects in older people and those at greater risk of nutritional deficiency deserves further attention.
The effectiveness and cost-effectiveness of minimal access surgery amongst people with gastro-oesophageal reflux disease – a UK collaborative study
(National Institute for Health Research, 2008-09) Grant, Adrian Maxwell; Wileman, Samantha Mary; Ramsay, Craig R; Bojke, Laura; Sculpher, Mark J.; Kilonzo, Mary Mueni; Vale, Luke David; Francis, Jillian Joy; Mowat, Ashley G.; Krukowski, Zygmunt H.; Campbell, Marion Kay; Epstein, David; Macran, Sue; Heading, Robert; Thursz, Mark; Russell, Ian; REFLUX Trial Group; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
*Corresponding author randomised arm of the trial (178 allocated to surgical management,179 allocated to continued, but optimised,medical management) and 453 recruited to the parallel non-randomised preference arm (261 chose surgical management, 192 chose to continue with best medical management). The type of fundoplication was left to the discretion of the surgeon. Main outcome measures: Participants completed a baseline reflux questionnaire, developed specifically for this study, containing a disease-specific outcome measure, the Short Form with 36 Items (SF-36), the EuroQol-5 Dimensions (EQ-5D) and the Beliefs about Medicines and Surgery questionnaires (BMQ/BSQ).Postal questionnaires were completed at participant specific time intervals after joining the trial (equivalent to approximately 3 and 12 months after surgery).Intraoperative data were recorded by the surgeons and all other in-hospital data were collected by the research nurse. At the end of the study period, participants completed a discrete choice experiment questionnaire. Results: The randomised groups were well balanced at entry. Participants had been taking GORD medication for a median of 32 months; the mean age of participants was 46 years and 66% were men. Of 178 randomised to surgery, 111 (62%) actually had fundoplication.There was a mixture of clinical and personal reasons why some patients did not have surgery, sometimes Objectives: To evaluate the clinical effectiveness, costeffectiveness and safety of a policy of relatively early laparoscopic surgery compared with continued medical management amongst people with gastro-oesophageal reflux disease (GORD) judged suitable for both policies. Design: Relative clinical effectiveness was assessed by a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgerybased policy with a continued medical management policy. The economic evaluation compared the costeffectiveness of the two management policies in order to identify the most efficient provision of future care and describe the resource impact that various policies for fundoplication would have on the NHS.Setting: A total of 21 hospitals throughout the UK with a local partnership between surgeon(s) and gastroenterologist(s) who shared the secondary care of patients with GORD.Participants: The 810 participants, who were identified retrospectively or prospectively via their participating clinicians, had both documented evidence of GORD (endoscopy and/or manometry/24-hour pH monitoring) and symptoms for longer than 12 months. In addition,the recruiting clinician(s) was clinically uncertain about which management policy was best.Intervention: Of the 810 eligible patients who consented to participate, 357 were recruited to the related to long waiting times. A total or partial wrap procedure was performed depending on surgeon preference. Complications were uncommon and there were no deaths associated with surgery. By the equivalent of 12 months after surgery, 38% in the randomised surgical group (14% amongst those who had surgery) were taking reflux medication compared with 90% in the randomised medical group. There were substantial differences (one-third to one-half standard deviation) favouring the randomised surgical group across the health status measures, the size depending on assumptions about the proportion that actually had fundoplication. These differences were the same or somewhat smaller than differences observed at 3 months. The lower the reflux score, the worse the symptoms at trial entry and the larger the benefit observed after surgery. The preference surgical group had the lowest reflux scores at baseline. These scores improved substantially after surgery, and by 12 months they were better than those in the preference medical group. The BMQ/BSQ and discrete choice experiment did distinguish the preference groups from each other and from the randomised groups. The latter indicated that the risk of serious complications was the most important single attribute of a treatment option. A within trial cost-effectiveness analysis suggested that the surgery policy was more costly (mean £2049) but also more effective [+0.088 quality-adjusted life-years (QALYs)]. The estimated incremental cost per QALY was £19,000–£23,000, with a probability between 46% (when 62% received surgery) and 19% (when all received surgery) of cost-effectiveness at a threshold of £20,000 per QALY. Modelling plausible longer-term scenarios (such as lifetime benefit after surgery) indicated a greater likelihood (74%) of costeffectiveness at a threshold of £20,000, but applying a range of alternative scenarios indicated wide uncertainty.The expected value of perfect information was greatest for longer-term quality of life and proportions of surgical patients requiring medication.Conclusions: Amongst patients requiring long-term medication to control symptoms of GORD, surgical management significantly increases general and refluxspecific health-related quality of life measures, at least up to 12 months after surgery. Complications of surgery were rare. A surgical policy is, however, more costly than continued medical management. At a threshold of £20,000 per QALY it may well be cost-effective, especially when putative longer-term benefits are taken into account, but this is uncertain.The more troublesome the symptoms, the greater the potential benefit from surgery. Uncertainty about cost-effectiveness would be greatly reduced by more reliable information about relative longer-term costs and benefits of surgical and medical policies. This could be through extended follow-up of the reflux trial cohorts or of other cohorts of fundoplication patients.
Systematic review of the effectiveness and cost-effectiveness of Healozone for the treatment of occlusal pit/fissure caries and root caries.
(Gray Publishing, 2006-05) Brazzelli, M; McKenzie, L.; Fielding, Shona; Fraser, Cynthia Mary; Clarkson, J.; Kilonzo, Mary Mueni; Waugh, N.
Systematic review of the effectiveness of preventing and treating Staphylococcus aureus carriage in reducing peritoneal catheter-related infections
(Gray Publishing, 2007-07) McCormack, Kirsty; Rabindranath, K.; Kilonzo, Mary Mueni; Vale, Luke David; Fraser, Cynthia Mary; McIntyre, L.; Thomas, Sumesh; Rothnie, H.; Fluck, N.; Gould, Ian M; Waugh, Norman Robert; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objectives: To determine the clinical effectiveness and cost-effectiveness of (1) alternative strategies for the prevention of Staphylococcus aureus carriage in patients on peritoneal dialysis (PD) and (2) alternative strategies for the eradication of S. aureus carriage in patients on PD. Data sources: Major electronic databases were searched up to December 2005 (MEDLINE Extra up to 6 January 2006). Review methods: Electronic searches were undertaken to identify published and unpublished reports of randomised controlled trials and systematic reviews evaluating the effectiveness of preventing and treating S. aureus carriage on peritoneal catheterrelated infections. The quality of the included studies was assessed and data synthesised. Where data were not sufficient for formal meta-analysis, a qualitative narrative review looking for consistency between studies was performed. Results: Twenty-two relevant trials were found. These fell into several groups: the first split is between prophylactic trials, aiming to prevent carriage, and trials which aimed to eradicate carriage in those who already had it; the second split is between antiseptics and antibiotics; and the third split is between those that included patients having the catheter inserted before dialysis started and people already on dialysis. Many of the trials were small or short-term. The quality was often not good by today’s standards. The body of evidence suggested a reduction in exit-site infections, but this did not seem to lead to a significant reduction in peritonitis, although to some extent this reflected insufficient power in the studies and a low incidence of peritonitis in them. The costs of interventions to prevent or treat S. aureus carriage are relatively modest. For example, the annual cost of antibiotic treatment of S. aureus carriage per identified carrier of S. aureus was estimated at £179 (£73 screening and £106 cost of antibiotic). However, without better data on the effectiveness of the interventions, it is not clear whether such costs are offset by the cost of treating infections and averting changes from peritoneal dialysis to haemodialysis. Although treatment is not expensive, the lack of convincing evidence of clinical effectiveness made cost-effectiveness analysis unrewarding at present. However, consideration was given to the factors needed in a hypothetical model describing patient pathways from methods to prevent S. aureus carriage, its detection and treatment and the detection and treatment of the consequences of S. aureus (e.g. catheter infections and peritonitis). Had data been available, the model would have compared the costeffectiveness of alternative interventions from the perspective of the UK NHS, but as such it helped identify what future research would be needed to fill the gaps. Conclusions: The importance of peritonitis isnot in doubt. It is the main cause of people having to switch from peritoneal dialysis to haemodialysis, which then leads to reduced quality of life for patients and increased costs to the NHS. Unfortunately, the present evidence base for the prevention of peritonitis is disappointing; it suggests that the interventions reduce exit-site infections, but not peritonitis, although this may be due to trials being in too small numbers for too short periods. Trials are needed with larger numbers of patients for longer durations.