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Placebo-controlled trial of essential fatty acid supplementation in atopic dermatitis.

Treatment of atopic dermatitis with essential fatty acids remains controversial. A double-blind, placebo-controlled, parallel-group study was done to investigate the response of patients with atopic dermatitis to essential fatty acid supplements. Patients with atopic dermatitis were randomised to receive evening primrose oil, evening primrose oil and fish oil, or placebo for 16 weeks. Disease activity was monitored by clinical severity scores recorded by the investigator, topical steroid requirement, and symptom scores recorded by subjects. Of 123 subjects recruited, 102 completed the treatment period. No improvement with active treatment was demonstrated. Our study, which avoided the methodological and analytical problems of previous studies, found no effect of essential fatty acid supplementation in atopic dermatitis.

Adult↗

[New technologies in laparoscopic surgery].

The technology associated with endoscopic surgery continues to evolve as a result of industrial R & D and research within academic surgical departments with interest in surgical endoscopic and remote handling technology. Some of the developments in the last ten years are reviewed. The problem concerning health technology assessment (HTA) in relation to new devices/instrumentation and procedures is discussed. Randomised controlled clinical trials are unsuited for the initial HTA of technology-dependent interventions, and for this reason, an alternative system, controlled stepwise evaluation (CSE) is proposed.

Clinical Trials as Topic↗

Forty years of randomised trials in the New Zealand Medical Journal.

AIM: To identify all randomised trials published in the New Zealand Medical Journal, to document the basic characteristics of these trials and to count the number that were detectable on medline. METHODS: All issues of the New Zealand Medical Journal between 1943 and 1995 were systematically hand-searched. All trials identified were characterised and compared against the trials identified using an optimal medline search strategy. RESULTS: The handsearch identified 152 randomised controlled trials, the first published in 1955. Half the trials recruited less than 34 participants and more than 90% were of pharmaceutical interventions. Only 18% of studies reported on the method of randomisation and 13% provided evidence that final analyses were conducted on an intention to treat basis. Fifty one percent of trials employed a placebo control group and 28% involved a crossover design. Since 1966, when Medline became available, 143 trials were published of which 89 (62%) were identified by the Medline search. CONCLUSIONS: Two of the major difficulties that face those preparing systematic reviews were illustrated by this survey. First, important information on design and analysis is often missing from reports of trials. Second, a large proportion of published randomised trials are not identifiable on Medline. Standard formats for reporting the results of trials and inclusion of trials identified by hand-searching on the Cochrane Collaboration's International Register of Randomised Controlled Trials of Health Care will facilitate the future production of reliable systematic reviews.

Data Interpretation, Statistical↗

Evaluation of new technologies for total hip replacement. Economic modelling and clinical trials.

Cost is a factor in the choice of prosthetic components in joint replacement. For a given performance, the least expensive components are the most cost-effective. When evaluating a new prosthesis with an unknown outcome, the use of an economic model allows estimation of potential cost-effectiveness. We used published data for the survival of cemented total hip replacements from Sweden, and cost and demographic information from New South Wales, Australia, in such a model. In young active total hip recipients a new prosthetic design which offered a 90% improvement in survivorship over 15 years and a 15% reduction in the cost of revision surgery, could be sold at a price of 2 to 2.5 times that of conventional cemented components such as the Charnley Low Friction Arthroplasty and still be cost-effective. Using more likely estimates of the improved performance of new technology, however, the upper limit of cost-effectiveness is an increase of 1.5 to 1. Only a very small increase in the cost of a prosthesis could ever be justified for older patients of either sex. Most of the potential benefits of a better level of survivorship appear towards the end of the 15-year period. The results of modelling may be incorporated in clinical trial design. Given the known performance of some well-established and relatively inexpensive designs of prostheses, very large randomised studies would be required to prove an improvement in performance.

Aged↗

Controversies in screening with mammography.

Screening with mammography in order to detect early curable breast cancer has been widely used during the last 2-3 decades. Especially an overview of 4 randomised trials in Sweden has shown a convincing short-term relative reduction of the breast cancer mortality while the long-term absolute effect on this mortality has been impossible to study due to screening of the control groups after some years. There is, however, rather general consensus about the value of screening in women above 50 years of age whereas screening in the age group 40-49 is still controversial due to the low rate of mammographically demonstrable cancers and the high rate of recalls for supplementary mammography, clinical examinations and biopsies in relation to cancers found. Recent follow-up of the pooled Swedish randomised trials have shown an about 20% almost significant reduction of the breast cancer mortality in women aged 40-49 at randomisation but the design of these trials does not allow an adequate estimation of the extra benefit obtained by starting periodical screening at age 40 instead of at age 50. The author proposes that screening in the age group 40-49 should be regarded as experimental and subject to proper randomised trials of a type on-going in UK and planned within UICC.

Adult↗

Chinese medicinal herbs for chronic hepatitis B.

BACKGROUND: Hepatitis B virus infection is a serious health problem worldwide. Traditional Chinese medicinal herbs have been widely used to treat chronic liver diseases, and many controlled trials have been done to investigate their efficacy. OBJECTIVES: To assess the efficacy and safety of traditional Chinese medicinal herbs for chronic hepatitis B infection. SEARCH STRATEGY: Searches were applied to the following electronic databases: the CHBG Trials Register, the Cochrane Complementary Medicine Field Trials Register, the Cochrane Library, MEDLINE, EMBASE and BIOSIS. Five Chinese journals and conference proceedings were handsearched. No language restriction was used. SELECTION CRITERIA: Randomised or quasi-randomised trials with at least three months follow-up. Trials of Chinese medicinal herbs (single or compound) compared with placebo, no intervention, general non-specific treatment or interferon treatment were included. Trials of Chinese medicinal herbs plus interferon versus interferon alone were also included. Trials could be double-blind, single-blind or not blinded. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers. The methodological quality of trials was evaluated using the Jadad-scale plus allocation concealment. Intention-to-treat analyses were performed. MAIN RESULTS: Nine randomised trials, including 936 patients, met the inclusion criteria. Methodological quality was considered adequate in only one trial. There was a significant funnel plot asymmetry (regression coefficient=3.37, standard error 1.40, P=0.047). Ten different medicinal herbs were tested in the nine trials. Compared to non-specific treatment or placebo, Fuzheng Jiedu Tang (compound of herbs) showed significantly positive effects on clearance of serum HBsAg, HBeAg, and HBV DNA; Polyporus umbellatus polysaccharide on serum HBeAg and HBV DNA; Phyllanthus amarus on serum HBeAg. Phyllanthus compound and kurorinone showed no significant effect on clearance of serum HBeAg and HBV DNA and on alanine aminotransferase normalisation compared to interferon treatment. There were no significant effects of the other examined herbs. REVIEWER'S CONCLUSIONS: Some Chinese medicinal herbs may work in chronic hepatitis B. However, the evidence is too weak to recommend any single herb. Rigorously designed, randomised, double-blind, placebo-controlled trials are required.

Drugs, Chinese Herbal↗

Cot-nursing versus incubator care for preterm infants.

BACKGROUND: An optimal thermal environment is desirable for preterm infants. These infants are usually nursed in incubators, but cot-nursing may provide an alternative. Measures to assist the maintenance of body temperature for smaller infants in open cots include extra clothing/bedding, warming up the nursery and heating the cot mattress. Recently a heated water-filled mattress has been developed to maintain the temperature of a cot-nursed preterm infant. While there may be benefits of nursing preterm infants in open cots, there may be potential risks such as nosocomial infection caused by more handling due to easier access. OBJECTIVES: Among preterm infants allocated to cot-nursing vs incubator care in neonatal period, to assess effects on their temperature control and weight gain. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of electronic databases: Oxford Database of Perinatal Trials; Cochrane Controlled Trials Register (Cochrane Library Issue 4 2001); MEDLINE (1966-2001); and CINAHL (1982-2001), previous reviews including cross references. SELECTION CRITERIA: All trials using random or quasi-random patient allocation in which infants receiving care in standard newborn cots were compared to infants managed in a conventional air heated incubator. DATA COLLECTION AND ANALYSIS: The authors independently assessed trial quality and extracted data for the primary outcomes of temperature control and weight gain. Meta-analysis was conducted using a fixed effects model. Results are presented as relative risk (RR) for categorical data and mean difference (MD) and weighted mean differences (WMD) for data measured on a continuous scale. MAIN RESULTS: Nine potential studies were identified of which four, involving 173 babies, were included in this review. When compared to incubator care, cot-nursing resulted in a statistically significantly higher mean body temperature (MD 0.30 degrees C; 95% CI 0.10, 0.50, one trial) and a decrease in proportion of infants not breast feeding at hospital discharge (RR 0.52; 95% CI 0.28, 0.94, two trials, 77 infants). No statistically significant difference was shown in weight gain, reported by two trials involving 69 infants. The comparison of cot-nursing using a heated water-filled mattress versus incubator care, which included four trials and a total of 149 infants, produced similar results. Cot-nursing with warming of the nursery resulted in statistically significantly smaller weight gain during week one compared to the incubator group in one trial that involved 49 infants (MD -5.90 g/kg/day; 95% CI -11.13, -0.67) with no significant difference found for weeks two and three. REVIEWER'S CONCLUSIONS: Due to the small numbers of trials included and infants studied, and the resulting imprecision in the measures of effect for all outcomes, the review does not give a clear indication for the role of cot-nursing for preterm infants. Further assessment of the role of cot nursing for preterm infants using randomised controlled trials is necessary.

Beds↗

Antidepressant drugs for narcolepsy.

BACKGROUND: Narcolepsy is a disorder of the central nervous system, the main symptoms of which are excessive daytime sleepiness (EDS) and cataplexy (an abrupt and reversible decrease in or loss of muscle tone, affecting the limbs and/or trunk, elicited by emotional stimuli). Narcolepsy has an adverse impact on people's quality of life. Together with stimulant drugs (used to control EDS), antidepressants are usually recommended to counteract cataplexy. In addition, some antidepressants are also reported to improve EDS. OBJECTIVES: To evaluate the effects of antidepressant drugs on EDS, cataplexy, quality of life, and their side effects in people with narcolepsy. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to 2003), EMBASE (1980 to 2003), PsycINFO (1872 to 2003), and CINAHL (1981 to 2003). Bibliographies of identified articles were reviewed to find additional references. Unpublished randomised trials were searched for by consulting governmental and non-governmental clinical trial registers, disease-specific websites, investigators and experts in the field, pharmaceutical companies/manufacturers. SELECTION CRITERIA: Parallel or cross-over randomised or quasi-randomised controlled trials testing the treatment of narcolepsy with any type of antidepressant drug versus no treatment, placebo, or another antidepressant drug. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion and extracted data. Outcomes were: (a) elimination of EDS; (b) mean reduction of EDS; (c) elimination of cataplexy; (d) 50% or greater reduction in cataplexy frequency; (e) mean reduction of cataplexy; (f) mean improvement in quality of life; (g) adverse events; (h) withdrawal from treatment. MAIN RESULTS: Two cross-over trials were included. The methodological quality of both studies was unclear and so the influence of common biases was impossible to define. As the trials tested two different comparisons (one femoxetine versus placebo, the other fluvoxamine versus clomipramine) meta-analysis was not performed. In the first trial (10 participants) femoxetine had no significant effect in eliminating or reducing EDS; a significant reduction of cataplexy was in favour of femoxetine. Mild and transient side effects were reported in the femoxetine treatment period by two participants. In the second trial the authors inappropriately treated the trial design as a parallel study and no conclusions can be reached in favour of either drug. AUTHORS' CONCLUSIONS: There was no good quality evidence that antidepressants are effective for narcolepsy or improve quality of life. Despite the clinical consensus recommending antidepressants for cataplexy there is scarce evidence that antidepressants have a positive effect on this symptom. There is a clear need for well-designed randomised controlled trials to assess the effect of antidepressants on narcolepsy.

Antidepressive Agents↗

Gauze and tape and transparent polyurethane dressings for central venous catheters.

BACKGROUND: Central venous catheters facilitate venous access, allowing the intravenous administration of complex drug treatments, blood products and nutritional support, without the trauma associated with repeated venepuncture. However, central venous catheters are associated with a risk of infection. Some studies have indicated that the type of dressing used for central venous catheters may affect the risk of infection. Gauze and tape or transparent polyurethane film dressings such as Tegaderm, Opsite or Opsite IV3000 are the most common types of dressing used to secure central venous catheters. Currently, it is not clear which type of dressing is the most appropriate. OBJECTIVES: To compare gauze and tape and transparent polyurethane central venous catheter dressings in terms of catheter related infection, catheter security, tolerance to dressing material and dressing condition in hospitalised adults and children. SEARCH STRATEGY: The Cochrane Wounds Group Specialised Trials Register (October 2002), the Cochrane Controlled Trials Register (4th Quarter 2002) and the databases; MEDLINE (1966-December 2002, CINAHL (1982-October 2002) and EMBASE (1980-December 2002) were searched to identify any randomised controlled trials comparing the effects of gauze and tape and/or transparent polyurethane dressings for central venous catheter sites. Additional references were identified from bibliographies of published literature and were also sought from other sources. SELECTION CRITERIA: All randomised controlled trials evaluating the effects of dressing type (i.e. gauze and tape and/or transparent polyurethane dressings) on central venous catheter related infection, catheter security, tolerance to dressing material and dressing condition in hospitalised patients. DATA COLLECTION AND ANALYSIS: Twenty-three studies were reviewed. Data was extracted from each paper by two members of the review team independently and results then compared. Differences were resolved either by consensus or by referral to a third member of the review team. Authors were contacted for missing information. MAIN RESULTS: Of the 23 studies reviewed, 14 were excluded. Nine studies were included. Data was only available for meta-analysis from six of the nine included studies. Of the six included studies with available data, two compared gauze and tape with Opsite IV3000, two compared Opsite with Opsite IV3000, one compared gauze and tape with Tegaderm, and one compared Tegaderm with Opsite. There was no evidence of any difference in the incidence of infectious complications between any of the dressing types compared in this review. Each of these comparisons was based on no more than two studies and all of these studies reported data from a small patient sample. Therefore it is probable that the finding of no difference between dressing types is due to the lack of adequate data. REVIEWER'S CONCLUSIONS: There is a high level of uncertainty regarding the risk of infection with the central venous catheter dressings identified in this review. Therefore, at this stage it appears that the choice of dressing for central venous catheters can be based on patient preference. To identify the most appropriate central venous catheter dressings, further research is necessary. It is paramount that any future studies investigating this issue must be rigorously performed randomised controlled trials.

Bacterial Infections↗

Anticoagulants for the treatment of recurrent pregnancy loss in women without antiphospholipid syndrome.

BACKGROUND: Since hypercoagulability might result in recurrent pregnancy loss, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained pregnancy loss. OBJECTIVES: To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (March 2004), the Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2004), MEDLINE (January 1966 to March 2004), and EMBASE (1980 to March 2004). We scanned bibliographies of all located articles for any unidentified articles. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on the live-birth rate in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias were eligible. Interventions included aspirin, unfractionated heparin, and low molecular weight heparin for the prevention of birth loss. One treatment could be compared with another or with placebo. DATA COLLECTION AND ANALYSIS: Two authors assessed the trials for inclusion in the review and extracted the data. Data were entered into the Review Manager software and double checked. MAIN RESULTS: Two studies (242 participants) were included in the review and for both of them data were extracted for the subgroups of women fulfilling the inclusion criteria of the review. In one study, 54 pregnant women with recurrent spontaneous abortion without detectable anticardiolipin antibodies were randomised to low-dose aspirin or placebo. Similar live-birth rates were observed with aspirin and placebo (relative risk (RR) 1.00, 95% confidence interval (CI) 0.78 to 1.29). In another study, a subgroup of 20 women who had had a previous fetal loss after the 20th week and had a thrombophilic defect were randomised to enoxaparin or aspirin. Enoxaparin treatment resulted in an increased live-birth rate, as compared to low-dose aspirin, RR 10.00, 95% CI 1.56 to 64.20). AUTHORS' CONCLUSIONS: The evidence on the efficacy and safety of thromboprophylaxis with aspirin and heparin in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias is too limited to recommend the use of anticoagulants in this setting. Large, randomised, placebo-controlled trials are urgently needed.

Abortion, Habitual↗

Dietary fibre and colorectal adenoma in a colorectal cancer early detection programme.

BACKGROUND: Although dietary fibre has been reported to have no association with colorectal adenoma and cancer, in some studies this topic remains controversial. METHODS: We used a 137-item food frequency questionnaire to assess the relation of fibre intake and frequency of colorectal adenoma. The study was done within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a randomised controlled trial designed to investigate methods for early detection of cancer. In our analysis, we compared fibre intake of 33971 participants who were sigmoidoscopy-negative for polyps, with 3591 cases with at least one histologically verified adenoma in the distal large bowel (ie, descending colon, sigmoid colon, or rectum). Odds ratios were estimated by logistic regression analysis. FINDINGS: High intakes of dietary fibre were associated with a lower risk of colorectal adenoma, after adjustment for potential dietary and non-dietary risk factors. Participants in the highest quintile of dietary fibre intake had a 27% (95% CI 14-38, p(trend)=0.002) lower risk of adenoma than those in the lowest quintile. The inverse association was strongest for fibre from grains and cereals and from fruits. Risks were similar for advanced and non-advanced adenoma. Risk of rectal adenoma was not significantly associated with fibre intake. INTERPRETATION: Dietary fibre, particularly from grains, cereals, and fruits, was associated with decreased risk of distal colon adenoma.

Adenoma↗

Generalisability of clinical trials in otitis media with effusion.

OBJECTIVE: The impact of a randomised controlled trial (RCT) upon practice depends on its external validity (generalisability). This paper summarises and illustrates a framework for judging and augmenting external validity, emphasising its application to treatment trials in otitis media with effusion (OME) so as to permit stronger inferences in the future. METHODS: The external validity of two surgical trials in the field of OME (TARGET, UK and KNOOP-3, the Netherlands) has been examined within a framework emphasising effect modification, in four specific ways: (1) comparison of the demographic characteristics of the trial population with the domain population; (2) studying the distributions on possible effect modifiers (i.e. variables conditioning the benefit from intervention); (3) studying whether effect modification occurs in the analyses; and (4) comparing outcome measures between the randomised and the eligible but non-randomised children. RESULTS: For neither KNOOP-3 and TARGET were large discrepancies found between randomised and non-randomised children for any of the demographic variables. Differences in distributions along possible effect modifiers were found, but the overlaps were large enough for it still to be possible to study whether these factors indeed modified the outcome. Results for the randomised and non-randomised but eligible patients were similar. The results of both trials therefore appear to be generalisable to their domain populations. CONCLUSIONS: A superficial contrast in the results (KNOOP null, TARGET positive) does not amount to a contradiction, because of differences in the clinical question appropriate to the respective age and populations defined. Attention to quality of design and external validity of randomised controlled trials should achieve higher applicability.

Child↗

The analgesic efficacy of intrathecal morphine compared to peripheral regional analgesia in total hip arthroplasty: A systematic review and meta-analysis.

BACKGROUND: Following elective total hip arthroplasty, pain continues to be a significant problem. Intrathecal morphine or peripheral regional analgesia, that is local infiltration analgesia or peripheral nerve block, are common analgesic modalities, but it is still not known which is superior. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: The following electronic databases were searched from inception to 24 March 2026: CENTRAL; Ovid Embase; Ovid MEDLINE; Scopus; and Web of Science. ELIGIBILITY CRITERIA: Randomised controlled trials that compared intrathecal morphine to peripheral regional analgesia in patients scheduled for elective total hip arthroplasty under general or spinal anaesthesia. RESULTS: Eight trials and 471 patients were included. The peripheral regional analgesia was peripheral nerve block in six trials and local infiltration analgesia in two trials. No difference was demonstrated between intrathecal morphine and peripheral regional analgesia in regard to the first coprimary outcome, the pain score at rest at 24 h. The quality of evidence was moderate. Intrathecal morphine was found to be superior to peripheral regional analgesia with respect to the second coprimary outcome, the cumulative intravenous morphine equivalent consumption at 24 h. Mean difference (95% CI) was 11.38 mg (4.31-18.45; P  = 0.002, I2  = 81%). The quality of evidence was low. Intrathecal morphine was revealed to be superior to peripheral regional analgesia at 8-12 h for the pain score at rest, 1.24 (0.60-1.88); P  = 0.0001, I2  = 68%; pain score on movement, 1.15 (0.12-2.17), P  = 0.03, I2  = 65%; but the rate of in hospital pruritus was reduced with peripheral regional analgesia, 0.31 (0.17-0.58), P  = 0.0002, I2  = 0%. No differences in functional status were shown. CONCLUSIONS: We found no difference between intrathecal morphine and peripheral regional analgesia in regard to pain score at rest at 24 h. Intrathecal morphine may lead to a favourable effect on some but not all analgesic indices compared to peripheral regional analgesia in elective total hip arthroplasty. The quality of evidence for these positive effects was low. Intrathecal morphine reduced the systemic opioid consumption, but is not in itself an opioid free strategy. This notion is supported by the increased incidence of in hospital pruritus with intrathecal morphine. The quality of evidence for this was high. In view of the quality of evidence, high quality randomised controlled trials are required to substantiate these results.

Humans↗

Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials.

OBJECTIVES: To determine whether parachutes are effective in preventing major trauma related to gravitational challenge. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists. STUDY SELECTION: Studies showing the effects of using a parachute during free fall. MAIN OUTCOME MEASURE: Death or major trauma, defined as an injury severity score > 15. RESULTS: We were unable to identify any randomised controlled trials of parachute intervention. CONCLUSIONS: As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

Accidents, Aviation↗