Is the allegiance effect an epiphenomenon of true efficacy differences between treatments? a meta-analysis

Many meta-analyses of comparative outcome studies found a substantial association of researcher allegiance (RA) and relative treatment effects. Therefore, RA is regarded as a biasing factor in comparative outcome research (RA bias hypothesis). However, the RA bias hypothesis has been criticized as causality might be reversed. That is, RA might be a reflection of true efficacy differences between treatments (true efficacy hypothesis). Consequently, the RA-outcome association would not be indicative of bias but an epiphenomenon of true efficacy differences. This meta-analysis tested the validity of the true efficacy hypothesis. This was done by controlling the RA-outcome association for true efficacy differences by restricting analysis to direct comparisons of treatments with equivalent efficacy. We included direct comparisons of different versions of trauma-focused therapy (TFT) in the treatment of posttraumatic stress disorder (PTSD). RA was measured from the research reports. Relative effect sizes for symptoms of PTSD were calculated. Random effects meta-regression was conducted. Twenty-nine comparisons of TFTs from 20 studies were identified. Initial heterogeneity among relative effect sizes was low. RA was a significant predictor of outcome and explained 12% of the variance in outcomes. The true efficacy hypothesis predicted the RA-outcome association to be zero; however, a substantial association was found. Thus, this study does not support the true efficacy hypothesis. Given findings from psychotherapy research and other fields that support a biasing influence of researcher preferences, RA should be regarded as a causal factor and conceptualized as a threat to the validity of conclusions from comparative outcome studies.

Fertility preservation in women with malignant tumors and gonadotoxic treatments

Because of improved survival rates and recent advances in reproductive medicine, fertility preservation methods in women of reproductive age with malignant or autoimmune diseases have risen in importance.

[Modalities of acupuncture treatments in assisted reproductive technology--a comparison of treatment practice in Swiss, German, and Austrian fertility centers with findings from randomized controlled trials]

One in 5 couples is affected by infertility. To increase the effectiveness of assisted reproductive technology (ART) adjuvant acupuncture treatments are frequently administered. However, little is known about acupuncture treatment modalities employed in fertility centers. The aim of our study was to assess modalities of acupuncture treatments in fertility centers and compare them with investigated acupuncture treatments in randomized controlled trials (RCTs) related to ART.

The pulmonary artery catheter: the tool versus treatments based on the tool

The pulmonary artery catheter (PAC) is a powerful tool that has been used extensively in the assessment and monitoring of cardiovascular physiology. Gross misinterpretation of data gathered by the PAC is common, and its routine use without any specific interventions has not been shown to influence outcome. However, there currently is no evidence from randomized, controlled trials that any diagnostic or monitoring tool used in intensive care patients improves outcome. Studies evaluating the use of the PAC have included numerous potential confounding factors, and should be interpreted with caution. The information obtained with the PAC should be used to find better treatment strategies, and these strategies, instead of the tool itself, should be tested in clinical trials.

Soil Chemical Response to Experimental Acidification Treatments

One of the conclusions reached during the Congressionally mandated National Acid Precipitation Program (NAPAP) was that, compared to ozone and other stress factors, the direct effects of acidic deposition on forest health and productivity were likely to be relatively minor. However, the report also concluded “the possibility of long-term (several decades) adverse effects on some soils appears realistic” (Barnard et al. 1990). Possible mechanisms for these long-term effects include: (1) accelerated leaching of base cations from soils and foliage, (2) increased mobilization of aluminum (Al) and other metals such as manganese (Mn), (3) inhibition of soil biological processes, including organic matter decomposition, and (4) increased bioavailability of nitrogen (N).

Influence of various surface treatments on reosseointegration around contaminated implants

The similarity of periodontitis and peri-implantitis demands for the utilization of similar principles for the treatment. Different decontamination methods were available cleaning of implant surfaces contaminated with bacteria. The aim of the present study was to evaluate the effects of various decontamination methods on reosseointegration on contaminated implants. Six mongrel dogs were used. The mandibular 1st molars and all premolars were removed bilaterally. Three months later, experi- mental implants with different surface characters were installed in each sides of the mandible. The implant consisted of two parts; the implant body and an exchangeable intraosseous implant cylinder. After osseointegration, experimental peri-implantitis was induced by cotton ligatures until the bone loss reached the junction of the two segments of the implant. After debridement of the bone defects, three treatment models were performed; (i) contaminated cylinders were removed, pristine cylinders were placed; (ii) contaminated cylinders were cleaned in situ with saline and (iii) contaminated cylinders was removed, cleaned with saline, sterilized by autoclaving. All implants were covered with membranes. After 3 months, histological evaluations were accomplished. The results indicated that in situ saline therapy demonstrated a significant difference at SLA surfaces in bone-implant-contact. Treatment of contaminated implants in situ with saline resulted in resolution of peri-implantitis and bone fill in defects.

Effect of zirconia surface treatments on the shear strength of zirconia/veneering ceramic composites

Aim of the investigation was to assess the effect of different surface treatments on the bond strength of veneering ceramics to zirconia. In a shear test, the influences of polishing, sandblasting, and silica-coating of the zirconia surface on bonding were assessed with five different veneering ceramics. In addition the effect of liner application was examined. With one veneering ceramic, the impact of regeneration firing of zirconia was also evaluated. Statistical analysis was performed with one-way ANOVA and post hoc Scheffé's test. Failure in every case occurred in the veneering ceramic adjacent to the interface with a thin layer of ceramic remaining on the zirconia surface, indicating that bond strength was higher than the cohesive strength of the veneering ceramic. Shear strength ranged from 23.5 +/- 3.4 MPa to 33.0 +/- 6.8 MPa without explicit correlation to the respective surface treatment. Regeneration firing significantly decreased the shear strength of both polished and sandblasted surfaces. Findings of this study revealed that bonding between veneering ceramics and zirconia might be based on chemical bonds. On this note, sandblasting was not a necessary surface pretreatment to enhance bond strength and that regeneration firing was not recommended.

Durability and outcome of initial antiretroviral treatments received during 2000--2005 by patients in the Swiss HIV Cohort Study

BACKGROUND: Little is known about time trends, predictors, and consequences of changes made to antiretroviral therapy (ART) regimens early after patients initially start treatment. METHODS: We compared the incidence of, reasons for, and predictors of treatment change within 1 year after starting combination ART (cART), as well as virological and immunological outcomes at 1 year, among 1866 patients from the Swiss HIV Cohort Study who initiated cART during 2000--2001, 2002--2003, or 2004--2005. RESULTS: The durability of initial regimens did not improve over time (P = .15): 48.8% of 625 patients during 2000--2001, 43.8% of 607 during 2002--2003, and 44.3% of 634 during 2004--2005 changed cART within 1 year; reasons for change included intolerance (51.1% of all patients), patient wish (15.4%), physician decision (14.8%), and virological failure (7.1%). An increased probability of treatment change was associated with larger CD4+ cell counts, larger human immunodeficiency virus type 1 (HIV-1) RNA loads, and receipt of regimens that contained stavudine or indinavir/ritonavir, but a decreased probability was associated with receipt of regimens that contained tenofovir. Treatment discontinuation was associated with larger CD4+ cell counts, current use of injection drugs, and receipt of regimens that contained nevirapine. One-year outcomes improved between 2000--2001 and 2004--2005: 84.5% and 92.7% of patients, respectively, reached HIV-1 RNA loads of <50 copies/mL and achieved median increases in CD4+ cell counts of 157.5 and 197.5 cells/microL, respectively (P < .001 for all comparisons). CONCLUSIONS: Virological and immunological outcomes of initial treatments improved between 2000--2001 and 2004--2005, irrespective of uniformly high rates of early changes in treatment across the 3 study intervals.

The James Lind Library: explaining and illustrating the evolution of fair tests of medical treatments

The James Lind Library (www.jameslindlibrary.org) has been established to improve public and professional general knowledge about fair tests of treatments in healthcare and their history. Its foundation was laid ten years ago at the Royal College of Physicians of Edinburgh, and its administrative centre is in the College's Sibbald Library, one of the most important collections of historic medical manuscripts, papers and books in the world. The James Lind Library is a website that introduces visitors to the principles of fair tests of treatments, with a series of short, illustrated essays, which are currently available in English, Arabic, Chinese, French, Portuguese, Russian and Spanish. A 100-page book-- Testing Treatments--is now available free through the website, both in English and in Arabic and Spanish translations. To illustrate the evolution of ideas related to fair tests of treatments from 2000 BC to the present, the James Lind Library contains key passages and images from manuscripts, books and journal articles, many of them accompanied by commentaries, biographies, portraits and other relevant documents and images, including audio and video files. New material is being added to the website continuously, as relevant new records are identified and as methods for testing treatments evolve. A multinational, multilingual editorial team oversees the development of the website, which currently receives tens of thousands of visitors every month.

Systemic conditions and treatments as risks for implant therapy

PURPOSE: To evaluate whether systemic diseases with/without systemic medication increase the risk of implant failure and therefore diminish success and survival rates of dental implants. MATERIALS AND METHODS: A MEDLINE search was undertaken to find human studies reporting implant survival in subjects treated with osseointegrated dental implants who were diagnosed with at least one of 12 systemic diseases. RESULTS: For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. For most systemic diseases there are only case reports or case series demonstrating that implant placement, integration, and function are possible in affected patients. For diabetes, heterogeneity of the material and the method of reporting data precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged. The data from papers reporting on osteoporotic patients were also heterogeneous. The evidence for an association between osteoporosis and implant failure was low. Nevertheless, some reports now tend to focus on the medication used in osteoporotic patients, with oral bisphosphonates considered a potential risk factor for osteonecrosis of the jaws, rather than osteoporosis as a risk factor for implant success and survival on its own. CONCLUSIONS: The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Studies comparing patients with and without the condition in a controlled setting are sparse. Especially for patients with manifest osteoporosis under an oral regime of bisphosphonates, prospective controlled studies are urgently needed.