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Biomedical subjects

A J Vickers

Publications and source records attributed to A J Vickers.

At least 19 recordsLinked to original sources
PubMed2006

Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes.

BACKGROUND: Influenza is a highly infectious viral disease that is particularly common in the winter months. Oscillococcinum is a patented, commercially available homoeopathic medicine. The rationale for its use in influenza comes from the homoeopathic principle of 'let like be cured by like'. This medicine is manufactured from wild duck heart and liver, which are said to be reservoirs for influenza viruses. OBJECTIVES: To determine whether homoeopathic Oscillococcinum or similar medicines are more effective than placebo in the prevention and treatment of influenza and influenza-like syndromes. SEARCH STRATEGY: We updated the electronic searches on the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006); MEDLINE (January 1966 to February 2006) and EMBASE (1980 to February 2006). The manufacturers of Oscillococcinum were contacted for information. SELECTION CRITERIA: Placebo-controlled trials of Oscillococcinum or homeopathically-prepared influenza virus, influenza vaccine or avian liver in the prevention and treatment of influenza and influenza-like syndromes. DATA COLLECTION AND ANALYSIS: Two authors extracted data and assessed methodological quality independently. MAIN RESULTS: Seven studies were included in the review, three prevention trials (number of participants (n) = 2265) and four treatment trials (n = 1194). Only two studies reported sufficient information to complete data extraction fully. There was no evidence that homoeopathic treatment can prevent influenza-like syndrome (relative risk (RR) 0.64, 95% confidence interval (CI) 0.28 to 1.43). Oscillococcinum treatment reduced the length of influenza illness by 0.28 days (95% CI 0.50 to 0.06). Oscillococcinum also increased the chances that a patient considered treatment to be effective (RR 1.08; 95% CI 1.17 to 1.00). AUTHORS' CONCLUSIONS: Though promising, the data were not strong enough to make a general recommendation to use Oscillococcinum for first-line treatment of influenza and influenza-like syndromes. Further research is warranted but the required sample sizes are large. Current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes.

Homeopathy↗
PubMed2004

Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes.

BACKGROUND: Influenza is a highly infectious viral disease that is particularly common in the winter months. Oscillococcinum is a patented, commercially available homoeopathic medicine. The rationale for its use in influenza comes from the homoeopathic principle of 'let like be cured by like'. The medicine is manufactured from wild duck heart and liver, which are said to be reservoirs for influenza viruses. OBJECTIVES: To determine whether homoeopathic Oscillococcinum or similar medicines are more effective than placebo in the prevention and treatment of influenza and influenza-like syndromes. SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials (CENTRAL) issue 2, 2003; MEDLINE (January 1966 to June 2003) and EMBASE (1980 to June 2003) were searched, using the term "homeopathy" with "influenza", "respiratory tract", "infection", "cough", "virus" and "fever". The manufacturers of Oscillococcinum were contacted for information. SELECTION CRITERIA: Placebo-controlled trials of Oscillococcinum or homeopathically-prepared influenza virus, influenza vaccine or avian liver in the prevention and treatment of influenza and influenza-like syndromes. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data and assessed methodological quality independently. MAIN RESULTS: Seven studies were included in the review, three prevention trials (n = 2265) and four treatment trials (n = 1194). Only for two studies was there sufficient information to complete data extraction fully. There was no evidence that homoeopathic treatment can prevent influenza-like syndrome (relative risk 0.64, 95% confidence interval 0.28 to 1.43). Oscillococcinum treatment reduced length of influenza illness by 0.28 days (95% confidence interval 0.50 to 0.06). Oscillococcinum also increased the chance of a patient considering treatment effective (relative risk 1.08; 95% CI 1.17, 1). REVIEWER'S CONCLUSIONS: Though promising, the data are not strong enough to make a general recommendation to use Oscillococcinum for first-line treatment of influenza and influenza-like syndrome. Further research is warranted but required sample sizes are large. Current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes.

Homeopathy↗
PubMed2004

Acupuncture of chronic headache disorders in primary care: randomised controlled trial and economic analysis.

OBJECTIVES: To determine the effects of a policy of using acupuncture, compared with a policy of avoiding acupuncture, on headache in primary care patients with chronic headache disorders. The effects of acupuncture on medication use, quality of life, resource use and days off sick in this population and the cost-effectiveness of acupuncture were also examined. DESIGN: Randomised, controlled trial. SETTING: General practices in England and Wales. PARTICIPANTS: The study included 401 patients with chronic headache disorder, predominantly migraine. INTERVENTIONS: Patients were randomly allocated to receive up to 12 acupuncture treatments over 3 months or to a control intervention offering usual care. MAIN OUTCOME MEASURES: Outcome measures included headache score; assessment of Short Form 36 (SF-36) health status and use of medication at baseline, 3 months and 12 months; assessment of use of resources every 3 months; and assessment of incremental cost per quality-adjusted life-year (QALY) gained. RESULTS: Headache score at 12 months, the primary end-point, was lower in the acupuncture group than in controls. The adjusted difference between means was 4.6. This result was robust to sensitivity analysis incorporating imputation for missing data. Patients in the acupuncture group experienced the equivalent of 22 fewer days of headache per year. SF-36 data favoured acupuncture, although differences reached significance only for physical role functioning, energy and change in health. Compared with controls, patients randomised to acupuncture used 15% less medication, made 25% fewer visits to GPs and took 15% fewer days off sick. Total costs during the 1-year period of the study were on average higher for the acupuncture group than for controls because of the acupuncture practitioners' costs. The mean health gain from acupuncture during the year of the trial was 0.021 QALYs, leading to a base-case estimate of GBP9180 per QALY gained. This result was robust to sensitivity analysis. Cost per QALY dropped substantially when the analysis incorporated likely QALY differences for the years after the trial. CONCLUSIONS: The study suggests that acupuncture leads to persisting, clinically relevant benefits for primary care patients with chronic headache, particularly migraine. It is relatively cost-effective compared with a number of other interventions provided by the NHS. Further studies could examine the duration of acupuncture effects beyond 1 year and the relative benefit to patients with migraine with compared to tension-type headache. Trials are also warranted examining the effectiveness and cost-effectiveness of acupuncture in patients with headache receiving more aggressive pharmacological management.

Acupuncture↗
PubMed2001

Time course of muscle soreness following different types of exercise.

BACKGROUND: Post-exercise muscle soreness is a dull, aching sensation that follows unaccustomed muscular exertion. Primarily on the basis of previous laboratory-based research on eccentric exercise, soreness is usually said to follow an inverted U-shaped curve over time, peaking 24 - 48 hours after exercise. As such, it is often described as "delayed-onset" muscle soreness. In a study of long-distance runners, soreness seemed to peak immediately and then reduce gradually over time. The study is a secondary analysis of clinical trial data that aims to determine whether the time course of soreness following a natural exercise, long-distance running, is different from that following a laboratory-based exercise, bench-stepping. METHODS: This is a reanalysis of data from three previous clinical trials. The trials included 400 runners taking part in long-distance races and 82 untrained volunteers performing a bench-stepping test. Subjects completed a Likert scale of muscle soreness every morning and evening for the five days following their exercise. RESULTS: Interaction between trial and time is highly significant, suggesting a different time course of soreness following running and bench-stepping. 45% of subjects in the bench-stepping trial experienced peak soreness at the third or fourth follow-up (approximately 36 - 48 hours after exercise) compared to only 14% of those in the running trial. The difference between groups is robust to multivariate analysis incorporating possible confounding variables. CONCLUSION: Soreness in runners following long-distance running follows a different time course to that in untrained individuals undertaking bench-stepping. Research on exercise taking place in the laboratory context does not necessarily generalize to exercise undertaken by trained athletes when engaged in their chosen sport.

Journal Article↗
PubMed2001

The use of percentage change from baseline as an outcome in a controlled trial is statistically inefficient: a simulation study.

BACKGROUND: Many randomized trials involve measuring a continuous outcome - such as pain, body weight or blood pressure - at baseline and after treatment. In this paper, I compare four possibilities for how such trials can be analyzed: post-treatment; change between baseline and post-treatment; percentage change between baseline and post-treatment and analysis of covariance (ANCOVA) with baseline score as a covariate. The statistical power of each method was determined for a hypothetical randomized trial under a range of correlations between baseline and post-treatment scores. RESULTS: ANCOVA has the highest statistical power. Change from baseline has acceptable power when correlation between baseline and post-treatment scores is high;when correlation is low, analyzing only post-treatment scores has reasonable power. Percentage change from baseline has the lowest statistical power and was highly sensitive to changes in variance. Theoretical considerations suggest that percentage change from baseline will also fail to protect from bias in the case of baseline imbalance and will lead to an excess of trials with non-normally distributed outcome data. CONCLUSIONS: Percentage change from baseline should not be used in statistical analysis. Trialists wishing to report this statistic should use another method, such as ANCOVA, and convert the results to a percentage change by using mean baseline scores.

Computer Simulation↗
PubMed2001

Message to complementary and alternative medicine: evidence is a better friend than power.

BACKGROUND: Evidence-based medicine (EBM) is being embraced by an increasing number of practitioners and advocates of complementary and alternative medicine (CAM). A significant constituency within CAM, however, appears to have substantive doubts about EBM and some are expressly hostile. DISCUSSION: Many of the arguments raised against EBM within the CAM community are based on a caricature radically at odds with established, accepted and published principles of EBM practice. Contrary to what has sometimes been argued, EBM is not cookbook medicine that ignores individual needs. Neither does EBM mandate that only proven therapies should be used. Before EBM, decisions on health care tended to be based on tradition, power and influence. Such modes usually act to the disadvantage of marginal groups. CONCLUSION: By placing CAM on an equal footing with conventional medicine - what matters for both is evidence of effectiveness - EBM provides an opportunity for CAM to find an appropriate and just place in health care.

Complementary Therapies↗
PubMed2001

Unconventional therapies for cancer and cancer-related symptoms.

A significant proportion of cancer patients try unconventional therapies and many use 'complementary' therapies, as adjuncts to mainstream care, for management of symptoms and to improve quality of life. A smaller proportion use 'alternative' therapies, which are typically invasive, biologically active, and commonly promoted as replacements for, rather than adjuncts to, mainstream therapy. Many alternative therapies, including high-dose vitamin C, the Di Bella regimen, and laetrile have been shown not to be effective. For others, such as metabolic therapy, evidence is extremely limited. Conversely, most complementary therapies are well studied and of proven benefit. There is evidence from randomised trials supporting the value of hypnosis for cancer pain and nausea; relaxation therapy, music therapy, and massage for anxiety; and acupuncture for nausea. Such complementary therapies are increasingly provided at mainstream cancer centres.

Anxiety↗
PubMed2001

Can homeopathically prepared mercury cause symptoms in healthy volunteers? A randomized, double-blind placebo-controlled trial.

OBJECTIVE: To pilot a method for determining whether homeopathically prepared mercury causes more symptoms (a "drug proving") in healthy volunteers than placebo. METHODS: One hundred and eighteen (118) healthy volunteers ages 18 to 65 were recruited by local advertising. Subjects unfamiliar with homeopathy undertook a 1-week single-blind placebo run-in, a 1-week of double-blind, randomized treatment on either homeopathically prepared mercury 12C or placebo, and a third week of placebo run-out. Each day, symptoms were recorded on a checklist that included both true mercury symptoms and symptoms not expected to be caused by mercury (false symptoms). Additional symptoms were assessed by open reporting. Outcome was assessed by calculating a score for each day as the number of true symptoms minus the number of false symptoms. The mean score during placebo was then subtracted from the mean score for weeks two and three of the trial. RESULTS: Fourteen (14) subjects dropped out during placebo run-in. The remaining 104 completed the trial. Baseline comparability was good. Mean difference score was -0.125 (SD 3.47) for mercury and -0.221 (SD 3.01) for placebo (p > 0.2). No significant differences between groups were found for the number of subjects meeting predefined criteria for a drug-proving reaction. CONCLUSION: This pilot study failed to find evidence that mercury 12C causes significantly more symptoms in healthy volunteers than placebo. Questionnaires with a limited number of gross symptoms do not seem to be an appropriate methodological technique in drug proving research. If drug-proving phenomena exist, they appear to be rare.

Adolescent↗
PubMed2000

Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes.

BACKGROUND: Influenza is a highly infectious viral disease that is particularly common in the winter months. Conventional management options are limited to bed rest and treatment of complications such as secondary bacterial infections. Oscillococcinum is a patented, commercially available homoeopathic medicine. The rationale for its use in influenza comes from the homoeopathic principle of 'let like be cured by like'. The medicine is manufactured from wild duck heart and liver, a well-known reservoir for influenza viruses. OBJECTIVES: To determine whether homoeopathic Oscillococcinum or similar medicines are more effective than placebo in the prevention and treatment of influenza and influenza-like syndromes. SEARCH STRATEGY: The registry of randomised trials for the Cochrane Complementary Medicine Field was searched using the term "homeopathy" with "influenza", "respiratory tract", "infection", "cough", "virus" and "fever". The manufacturers of Oscillococcinum were contacted for information about other trials. Date of the most recent search: February 1999. SELECTION CRITERIA: Placebo-controlled trials of Oscillococcinum or homeopath-prepared influenza virus, influenza vaccine or avian liver in the prevention and treatment of influenza and influenza-like syndromes. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data and assessed methodological quality independently. MAIN RESULTS: Seven studies were included in the review, three prevention trials (n=2265) and four treatment trials (n=1194). Only for two studies was there sufficient information to complete data extraction fully. There was no evidence that ic treatment can prevent influenza-like syndrome (relative risk 0.64, 95% confidence interval 0.28 to 1.43). Oscillococcinum treatment reduced length of influenza illness by 0.28 days (95% confidence interval 0.50 to 0.06). Oscillococcinum also increased the chance of a patient considering treatment effective (relative risk 1.08; 95% CI 1.17, 1). REVIEWER'S CONCLUSIONS: Oscillococcinum probably reduces the duration of illness in patients presenting with influenza symptoms. Though promising, the data are not strong enough to make a general recommendation to use Oscillococcinum for first-line treatment of influenza and influenza-like syndrome. Further research is warranted but required sample sizes are large. Current evidence does not support a preventative effect of homeopathy in influenza and influenza-like syndromes.

Homeopathy↗
PubMed2000

Why use placebos in clinical trials? A narrative review of the methodological literature.

Researchers have a number of different options for their choice of control or comparison intervention in randomized trials. We surveyed the methodological literature looking for reasons why a researcher might choose to administer a placebo (i.e., a mimic intervention) to control subjects. Two implicit assumptions were that the issue of placebo is pertinent only to drug trials and that the nonplacebo effect of a treatment is the "real" or "true" effect. Explicit reasons given in the literature for the use of placebos were facilitating blinding and controlling for the placebo effect. The importance of the latter was often inadequately argued. Reasons to avoid placebos in controlled trials, other than ethics and feasibility, are that placebos do not inform real decisions, and may interfere with accurate estimation of effect size and with nonspecific aspects of treatment. Placebo-controlled trials have high internal validity but may be difficult to apply to clinical practice; the situation is reversed for trials without placebo control.

Double-Blind Method↗
PubMed2000

Incorporating data from dissertations in systematic reviews.

OBJECTIVES: To determine whether unpublished dissertations are an important source of trials for systematic reviews. METHODS: In a review of infant massage, we identified 17 dissertations. We recorded whether each dissertation was included in the review and, if so, whether it contributed data to any analyses. RESULTS: Thirteen dissertations were excluded, 11 because of poor reporting of methodology. Three dissertations were also published as journal papers. The data from the remaining dissertation were not included in any analysis. Reviewing data on the Cochrane Library, only one of 878 reviews included data from a dissertation that might have changed a review's conclusions. CONCLUSIONS: Searching for and retrieving unpublished dissertations involves considerable time and effort and appears to influence the conclusions of a review only rarely.

Academic Dissertations as Topic↗
PubMed2000

Inter-rater reliability of symptom repertorisation: a pragmatic empirical study.

OBJECTIVE: To determine the extent to which two homeopaths agree on whether symptoms reported by patients in a proving are possibly associated with Mercurius solubilis. DESIGN: Blinded, inter-rater reliability study. PARTICIPANTS: 104 subjects in a randomised, double-blind mercury proving. OUTCOME MEASURES: 557 symptom episodes spontaneously reported by subjects were classified as 'mercury' or 'not mercury' by two homeopaths working blind to each other's conclusions and to patient allocation. RESULTS: Initial agreement between homeopaths was 70.2%, a kappa of 0.39, (95% CI 0.31, 0.47). Some disagreements appear to have resulted from differing interpretations of the study instructions. After suitable correction, agreement was 76.5% and kappa 0.56 (95% CI 0.49, 0.63). CONCLUSIONS: The study homeopaths had only a moderate level degree of agreement greater than that expected by chance. The main factor seems to have been differences between data from different sources. There is an urgent need for more research on the methods of choosing homoeopathic medicines in order to improve the reliability and validity of homoeopathic diagnoses.

Adolescent↗
PubMed2000

Clinical trials of homeopathy and placebo: analysis of a scientific debate.

OBJECTIVE: Homeopathy is controversial, primarily because of the use of medicines diluted beyond the Avogadro limit. This article examines the scientific debate on whether homeopathy can have effects greater than placebo in humans. METHODS: Five rigorous English-language clinical studies published in high-impact journals that favored homeopathy were identified. Letters and other articles written in response to these articles were then retrieved and analyzed. RESULTS: Much of the content of responses to positive homeopathic research was rhetorical in nature and antagonistic in tone: homeopathic researchers were accused of bias and of being in the pocket of homeopathic manufacturers; arguments were raised that are demonstrably inaccurate or irrelevant to the interpretation of research; words such as "magic" or "potion" were used to paint homeopathic research as inherently unscientific. Other commentators argued that based on theoretical grounds homeopathy could not possibly be effective, any positive trial result must be due to bias. Surprisingly few responses raised substantive methodologic or statistical issues. Many of these are clearly inaccurate or irrelevant. The possibility of publication bias-selective publication of positive results-was raised by some commentators and remains an important criticism of the apparently positive nature of the clinical trial evidence. The most persuasive argument against accepting differences between homeopathy and placebo on the basis of current evidence is that homeopathy is scientifically implausible and so requires more evidence than normal. CONCLUSIONS: Investigators undertaking clinical research in homeopathy need to be responsive both to the dangers of publication bias and to the requirement for stronger than usual levels of evidence.

Clinical Trials as Topic↗
PubMed1999

Independent replication of pre-clinical research in homeopathy: a systematic review.

OBJECTIVE: To determine whether any pre-clinical research in homoeopathy has been independently replicated. SEARCH STRATEGY: CISCOM was searched using the key words 'homeopathy' and 'basic research'. Further references were obtained from reviews, bibliographies, citation tracking and contact with experts. SELECTION CRITERIA: Studies comparing the effects of one or more homoeopathic medicines to no homoeopathic treatment on any live biological material apart from humans or animals under veterinary care. Research on intoxication and basophil degranulation was excluded. DATA COLLECTION AND ANALYSIS: Publications were grouped in experimental models. Studies were considered to comprise the same model if the outcome variable, biological material and homoeopathic treatment were the same. Publications relating to each experimental model were then arranged in chronological order. A model was considered to have been independently replicated if the first author was different and fewer than half of all authors had previously published research using that model. RESULTS: 120 papers reported 61 different experimental models. Only three models were investigated by different research teams: growth of yeast, growth of wheat coleoptiles and ultra-violet-induced erythema in albino guinea pigs. In the case of yeast, attempts to replicate findings showing increased growth after treatment with Pulsatilla were unsuccessful. For wheat, two experiments by different research teams were conducted, but no single hypothesis was tested in both papers with the same result. Different research teams conducted very similar experiments on erythema treatment by Apis, but the methodological quality of the publications was low. CONCLUSIONS: There is a lack of independent replication of any pre-clinical research in homoeopathy. In the few instances where a research team has set out to replicate the work of another, either the results were negative or the methodology was questionable.

Animals↗
PubMed1999

Comparison of an ordinal and a continuous outcome measure of muscle soreness.

The relationship between an ordinal (Likert) and a continuous (visual analog) measure of pain was investigated in 400 long-distance runners experiencing delayed-onset muscle soreness. Subjects completed a 100-mm visual analog scale (VAS) and a 7-point Likert scale twice a day for 5 days, starting at 9:00 PM on the evening of the run. The relationship between scales was modeled by calculating the median VAS for each Likert score and the modal Likert score for each point on the VAS. Standardized means were calculated by dividing the total of 5 day scores by the standard error of 5 day scores for all subjects. The relationship between scales was approximately linear, but VAS scores recorded concurrently with each Likert score varied enormously. VAS responses for a Likert score of zero were lower than expected, apparently because subjects chose zero only if they were completely free of soreness. The standardized mean of the Likert scale was higher (34.1 [SD 20] versus 30.4 [SD20] p < < < .0001), suggesting greater responsiveness. The Likert scale can be recommended as a method of measuring muscle soreness, but researchers should not anchor the lowest score to zero pain.

Bias↗