Etiology in a Taxonomy of Illnesses

According to what Robert Koch termed the etiological standpoint, illnesses are best understood and controlled by focusing on their causes, including in their definitions and, thus, in the construction of their taxonomies. In some ways flawed, this standpoint has been misunderstood and misapplied. A taxonomy based solely on etiology was an unrealistic dream in the context of ‘the bacteriological revolution', and it also is unrealistic in the present context of ‘the genetic revolution.' We argue that the illnesses in a taxonomy of them are in some cases best defined directly in terms of their respective somatic anomalies, in some others indirectly by the unique and universal etiology of that anomaly (left unspecified) in a ‘deeper' somatic anomaly, and in yet others as a combination of these; and when the somatic anomaly for direct definition remains unknown, it is to be defined indirectly by the clinical syndrome that is its patient-relevant manifestation, possibly in conjunction with a somatic cause. We note, also, that these taxonomic issues have no material bearing on epidemiologists' etiologic research for the knowledge base of community-level preventive medicin

Oral purified bacterial extracts in acute respiratory tract infections in childhood: a systematic quantitative review

Background: Recurrent acute respiratory tract infections (ARTI) are a common problem in childhood. Some evidence suggests a benefit regarding the prevention of ARTI in children treated with the immunomodulator OM-85 BV (Bronchovaxom). Methods: We summarised the evidence on the effectiveness of the immunomodulator OM-85 BV in the prevention of ARTI in children. We searched randomised comparisons of oral purified bacterial extracts against inactive controls in children with respiratory tract diseases in nine electronic databases and reference lists of included studies. We extracted salient features of each study, calculated relative risks (RR) or weighted mean differences (WMD) and performed meta-analyses using random-effects models. Results: Thirteen studies (2,721 patients) of low to moderate quality tested OM-85 BV. Patients and outcomes differed substantially, which impeded pooling results of more than two trials. Two studies (240 patients) reporting on the number of patients with less than three infections over 6 month of follow-up in children not in day care showed a trend for benefit RR 0.82 (95% CI, 0.65-1.02). One out of two studies examining the number of children not in day care without infections over 4-6 month reported a significant RR of 0.42 (95% CI, 0.21-0.82) whereas the smaller, second study did not [RR 0.92 (95% CI, 0.58-1.46)]. Two studies reporting the number of antibiotic courses indicated a benefit for the intervention arm [WMD 2.0 (95% CI, 1.7-2.3)]. Two out of the three studies showed a reduction of length of episodes of 4-6 days whereas a third study showed no difference between the two groups. Conclusion: Evidence in favour of OM-85 BV in the prevention of ARTI in children is weak. There is a trend for fewer and shorter infections and a reduction of antibiotic us

Preventive health risk appraisal for older people and impact on GPs' patient management: a prospective study

Background. Health risk appraisals (HRAs) are recommended for detection of potentially modifiable risk factors for health status decline of older people. Little is known how family physicians manage detected risk factors. Objective. We evaluated (i) if risk factors in one or more of five predefined domains were detected in a primary care-based HRA and (ii) how often these findings had an impact on the further management of patients. Methods. We performed a prospective observational study in a rural community in Austria and included persons (age ≥ 70 years) living at home. We applied the standardized assessment for elderly people in primary care (STEP) instrument and evaluated risk factors for status decline assessing five domains (cognitive function, depression, urinary incontinence, hearing impairment and mobility/falls). Results. Two hundred and sixty-four persons participated and the HRA revealed a wide range of risk factors for health status decline [from 4.5% (12/264) in the depression domain up to 31% (81/264) for mobility/falls and 41% (107/264) in the cognitive domain]. The findings had an impact on the further management in four domains: hearing impairment (100% of findings with impact), mobility/falls (93%), depression (83%) and urinary incontinence (65%). In contrast, abnormal cognitive findings lead to action only in every fifth participant (18%; 19/107). Conclusion. In contrast to other domains, family physicians are hesitant to act upon abnormal findings of cognitive testing. Additional knowledge is needed to clarify the value of abnormal cognitive findings for management of patients and support of their carer

Cognitive-behavioural treatment for weight loss in primary care : a prospective study

Questions under Study: Cognitive-behavioural treatment (CBT) is effective for weight loss in obese patients, but such programmes are difficult to implement in primary care. We assessed whether implementation of a community-based CBT weight loss programme for adults in routine care is feasible and prospectively assessed patient outcome. Patients and Methods: The weight loss programme was provided by a network of Swiss general practitioners in cooperation with a community centre for health education. We chose a five-step strategy focusing on structure of care rather than primarily addressing individual physician behaviour. A multidisciplinary core group of trained CBT instructors acted as the central element of the programme. Overweight and obese adults from the community (BMI >25 kg/m2) were included. We used a patient perspective to report the impact on delivery of care and assessed weight change of consecutive participants prospectively with a follow-up of 12 months. Results: Twenty-eight courses, with 16 group meetings each, were initiated over a period of 3 years. 44 of 110 network physicians referred patients to the programme. 147 of 191 study participants were monitored for one year (attrition rate: 23%). Median weight loss after 12 months for 147 completers was 4 kg (IQR: 1-7 kg; intention-to-treat analysis for 191 participants: 2 kg, IQR: 0-5 kg). Conclusions: The programme produced a clinically meaningful weight loss in our participants, with a relatively low attrition rate. Implementation of an easily accessible CBT programme for weight loss in daily routine primary care is feasible

Relevant baseline characteristics for describing patients with knee osteoarthritis: results from a Delphi survey

BACKGROUND: Inclusion/exclusion criteria and baseline characteristics are essential for assessing the applicability of trial results to a given patient and the comparability of study populations for meta-analyses. This Delphi survey aimed to generate a set of baseline characteristics for describing patients with knee osteoarthritis enrolled in clinical studies. METHODS: Survey participants comprised clinical experts (n = 23; mean age 54 y; from 4 continents) that had authored at least two randomized trials on knee osteoarthritis. First, given a prepared list of baseline patient characteristics, the experts were asked to add characteristics they considered important for assessing comparability of patient populations in different trials that evaluated the efficacy of non-surgical interventions for treating knee osteoarthritis. Next, they were asked to rate the importance of each characteristic, on a scale of 0 (not important) to 10 (highly important), according to three outcome categories: pain, function, and structure. RESULTS: Participants identified 121 baseline characteristics. A rating ≥7 points was assigned to 39 characteristics (e.g., age, depression, global knee pain, daily dose of pain killers, Kellgren-Lawrence grading); of these, 20 were related to pain, 15 to function, and 23 to structural outcomes. Global knee pain was the only baseline characteristic that fulfilled among experts the predefined consensus criteria. CONCLUSIONS: Experts identified a large number of characteristics for describing patients with knee osteoarthritis. Disagreement and uncertainty prevailed over the relevance of these characteristics. Our findings justified further efforts to define appropriate, broadly acceptable sets of baseline characteristics for describing patients with knee osteoarthritis

Where is the supporting evidence for treating mild to moderate chronic obstructive pulmonary disease exacerbations with antibiotics? A systematic review

BACKGROUND: Randomised trials comparing different drugs head-to-head are extremely valuable for clinical decision-making. However, it is scientifically and ethically sensible to demand strong evidence that a drug is effective by showing superiority over a placebo before embarking on head-to-head comparisons of potentially ineffective drugs. Our aim was to study the evolvement of evidence from placebo-controlled and head-to-head trials on the effects of antibiotics for the treatment of mild to moderate exacerbations of chronic obstructive pulmonary disease. METHODS: We conducted a historical systematic review. Through electronic databases and hand-searches, we identified placebo-controlled and head-to-head antibiotic trials for the treatment of mild to moderate chronic obstructive pulmonary disease exacerbations. We compared the numbers of patients recruited in placebo-controlled and head-to-head trials between 1957 and 2005. Using cumulative meta-analysis of placebo-controlled trials, we determined when, if ever, placebo-controlled trials had shown convincing evidence that antibiotics are effective in preventing treatment failure in patients with mild to moderate chronic obstructive pulmonary disease exacerbations. RESULTS: The first head-to-head trial was published in 1963. It was followed by another 100 trials comparing different antibiotics in a total of 34,029 patients with mild to moderate chronic obstructive pulmonary disease exacerbations. Over time, the cumulative odds ratio in placebo-controlled trials remained inconclusive throughout with odds ratios ranging from 0.39 (95% confidence intervals 0.04-4.22) to the most recent estimate (1995) of 0.81 (95% confidence intervals 0.52-1.28, P = 0.37). CONCLUSION: Placebo-controlled trials do not support the use of antibiotics in chronic obstructive pulmonary disease patients with mild to moderate exacerbations. Conducting head-to-head trials is, therefore, scientifically and ethically questionable. This underscores the requirement to perform or study systematic reviews of placebo-controlled trials before conducting head-to-head trials