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At least 199 records · Page 11Linked to original sources

PubMed1998

Positive fraction of systematic biopsies predicts risk of relapse after radical prostatectomy.

OBJECTIVES: To determine whether the positive fraction of systematic sextant biopsies contributes to the prediction of serologic relapse after radical prostatectomy. METHODS: A retrospective review of patients who underwent transrectal ultrasound-guided systematic sextant biopsy and radical prostatectomy was performed. No patients received neoadjuvant or adjuvant therapy. The relationship between the positive fraction of systematic biopsies and risk of prostate-specific antigen recurrence was assessed with Kaplan-Meier and multivariate analyses. RESULTS: Patients with three or fewer positive sextant biopsies were at a significantly lower risk of relapse after radical prostatectomy than patients with four or more positive biopsies. Tumor grade and systematic biopsy results were the most powerful predictors of serologic relapse. CONCLUSIONS: The positive fraction of systematic biopsies contributes to the prediction of risk of relapse after radical prostatectomy.

Aged↗

PubMed1996

Completeness of reporting of trials published in languages other than English: implications for conduct and reporting of systematic reviews.

BACKGROUND: Lately, the number of systematic reviews published has increased substantially. Many systematic reviews exclude trials published in languages other than English. However, there is little empirical evidence to support this action. We looked for differences in the completeness of reporting between trials published in other languages and those published in English, to see whether the exclusion of trials published in other languages is justified. METHODS: We compared completeness of reporting, design characteristics, and analytical approaches of 133 randomised controlled trials (RCTs) published in English between 1989 and 1994 and 96 published in French, German, Italian, or Spanish during the same time. RCTs were identified by hand searching of journals (seven in English and six in the other languages). FINDINGS: We found no significant differences between trials published in English and other-language trials for any single item in the completeness of reporting scale (randomisation, double-blinding, withdrawals), or for the overall score (percentage of maximum possible score 51.0% for trials in English, 46.2% for trials in other languages; 95% CI for difference -1.1 to 10.5). Other-language trials were more likely than English-language trials to have adult participants, to use two or more interventions, and to compare two or more active treatments without an untreated control group. Trials in other languages were less likely to report a clearly prespecified primary outcome or any rationale for sample size estimation. INTERPRETATION: These results provide evidence for inclusion of all trial reports, irrespective of the language in which they are published, in systematic reviews. Their inclusion is likely to increase precision and may reduce systematic errors. We hope that our findings will prove useful to those developing guidelines and policies for the conduct of reporting of systematic reviews.

Adult↗

PubMed2001

Analysis and reduction of 3D systematic and random setup errors during the simulation and treatment of lung cancer patients with CT-based external beam radiotherapy dose planning.

PURPOSE: To determine the magnitude of the errors made in (a) the setup of patients with lung cancer on the simulator relative to their intended setup with respect to the planned treatment beams and (b) in the setup of these patients on the treatment unit. To investigate how the systematic component of the latter errors can be reduced with an off-line decision protocol for setup corrections. METHODS AND MATERIALS: For 39 patients with CT planning, digitally-reconstructed radiographs (DRRs) were calculated for anterior-posterior and lateral beams. Retrospectively, the position of the visible anatomy relative to the planned isocenter was compared with the corresponding position on the digitized simulator radiographs using contour match software. The setup accuracy at the treatment unit relative to the simulator setup was measured for 40 patients for at least 5 fractions per patient in 2 orthogonal beams with the aid of an electronic portal imaging device (EPID). Setup corrections were applied, based on an off-line decision protocol, with parameters derived from knowledge of the random setup errors in the studied patient group. RESULTS: The standard deviations (SD) of the simulator setup errors relative to the CT planning setup in the lateral, longitudinal, and anterior-posterior directions were 4.0, 2.8, and 2.5 mm, respectively. The SD of rotations around the anterior-posterior axis was 1.6 degrees and around the left-right axis 1.3 degrees. The setup error at the treatment unit had a small random component in all three directions (1 SD = 2 mm). The systematic components were larger, particularly in the longitudinal direction (1 SD = 3.6 mm), but were reduced with the decision protocol to 1 SD < 2 mm with, on average, 0.6 setup correction per patient. CONCLUSION: Setup errors at the simulator, which become systematic errors if the simulation defines the reference setup, were comparable to the systematic setup errors at the treatment unit in case no off-line protocol would have been applied. Hence, the omission of a separate simulation step can reduce systematic errors as efficiently as the application of an off-line correction protocol during treatment. The random errors were sufficiently small to make an off-line protocol feasible.

Algorithms↗

PubMed2000

Methods for systematic reviews of economic evaluations for the Guide to Community Preventive Services. Task Force on Community Preventive Services.

OBJECTIVES: This paper describes the methods used in the Guide to Community Preventive Services: Systematic Reviews and Evidence-Based Recommendations (the Guide) for conducting systematic reviews of economic evaluations across community health-promotion and disease-prevention interventions. The lack of standardized methods to improve the comparability of results from economic evaluations has hampered the use of data on costs and financial benefits in evidence-based reviews of effectiveness. The methods and instruments developed for the Guide provide an explicit and systematic approach for abstracting economic evaluation data and increase the usefulness of economic information for policy making in health care and public health. METHODS: The following steps were taken for systematic reviews of economic evaluations: (1) systematic searches were conducted; (2) studies using economic analytic methods, such as cost analysis or cost-effectiveness, cost-benefit or cost-utility analysis, were selected according to explicit inclusion criteria; (3) economic data were abstracted and adjusted using a standardized abstraction form; and (4) adjusted summary measures were listed in summary tables. RESULTS: These methods were used in a review of 10 interventions designed to improve vaccination coverage in children, adolescents and adults. Ten average costs and 14 cost-effectiveness ratios were abstracted or calculated from data reported in 24 studies and expressed in 1997 USD. The types of costs included in the analysis and intervention definitions varied extensively. Gaps in data were found for many interventions.

Abstracting and Indexing↗

PubMed2001

Impact of systematic false-negative test results on the performance of faecal occult blood screening.

The impact of systematic false-negative test results on mortality reduction and on programme sensitivity of annual faecal occult blood testing in ages 50-84 years is explored using a microsimulation model. We made calculations for test sensitivities of 80, 50 and 30%. In order to reproduce a cancer detection rate of 2.2 per 1000 at the first screening, the corresponding mean preclinical sojourn times had to be 1.42, 2.30 and 3.84 years, respectively. The fraction systematic results among the false-negative results is varied between 0 and 100%. With 80% test sensitivity, the reduction in mortality due to screening decreases from 25% without systematic results to 23% when all false-negative results are systematic and the programme sensitivity decreases from 63 to 58%. With 30% test sensitivity, mortality reduction decreases from 21 to 11% and programme sensitivity decreases from 52 to 27%. The impact of systematic false-negative test results is important if annual FOBT screening is considered.

Aged↗

PubMed2004

Use of systematic reviews in the development of new provincial public health policies in Ontario.

OBJECTIVES: The study determined whether the results of recently completed systematic reviews evaluating the effectiveness of public health interventions were used in the development of new provincial policies for public health practice. METHODS: This telephone survey included all members from five review groups who updated the Ontario Mandatory Health Programs and Services guidelines for Public Health in 2000. Independent variables included characteristics of the systematic reviews, organization, and the individual. Outcomes included the use of the reviews in developing new policies and the extent to which the reviews led to new recommendations for practice. Descriptive summaries as well as multiple linear regression were conducted. RESULTS: Eighty-five percent of decision-makers agreed to participate in the study. Ninety-six percent of respondents reported that the systematic reviews played a part in developing the new guidelines, while 47 percent indicated that the reviews contributed a great deal to the development of new recommendations for practice. The multiple linear regression model explained 42 percent of the variation in use of the reviews for developing new recommendations for practice. Significant predictor variables included the importance of the reviews in comparison to other sources of information and relevance of the reviews to the policy decisions. CONCLUSION: Public health decision-makers in Ontario have very positive perceptions of the usefulness of systematic reviews in policy development. Therefore, ongoing efforts to promote the usefulness and relevance of systematic reviews to public health decision-makers should remain a priority for health services researchers.

Cross-Sectional Studies↗

PubMed1994

Heuristic processing can bias systematic processing: effects of source credibility, argument ambiguity, and task importance on attitude judgment.

High- and low-task-importance Ss read a strong or weak unambiguous message or an ambiguous message that was attributed to a high- or low-credibility source. Under low task importance, heuristic processing of the credibility cue was the sole determinant of Ss' attitudes, regardless of argument ambiguity or strength. When task importance was high and message content was unambiguous, systematic processing alone determined attitudes when this content contradicted the validity of the credibility heuristic; when message content did not contradict this heuristic, systematic and heuristic processing determined attitudes independently. Finally, when task importance was high and message content was ambiguous, heuristic and systematic processing again both influenced attitudes. Yet, source credibility affected persuasion partly through its impact on the valence of systematic processing, confirming that heuristic processing can bias systematic processing when evidence is ambiguous. Implications for persuasion and other social judgment phenomena are discussed.

Adult↗

PubMed2004

The quality of systematic reviews in dentistry.

DATA SOURCES: Sources of reviews were the Database of Reviews of Effectiveness (DARE) and completed systematic reviews registered by the Cochrane Oral Health Group in the Cochrane Library. STUDY SELECTION: All systematic reviews that examined the effectiveness of interventions for oral, dental and craniofacial disorders and diseases were eligible for inclusion. DATA EXTRACTION AND SYNTHESIS: A quality assessment checklist was completed for each study. RESULTS: A total of 115 studies were identified, of which 65 were relevant to the review. The area most frequently evaluated within the reviews was pain relief or prevention (20 out of 65, ie, 31%) followed by caries, and oral medicine. The quality assessment of the systematic reviews identified highlighted key areas where improvements could be made. One major weakness was that the search strategies employed in reviews were not always adequate: only 12 reviews (19%) demonstrated an attempt to identify all relevant studies. Other areas of weakness include the screening and quality assessment of primary studies, the pooling of data and examination of heterogeneity, and the interpretation of findings. CONCLUSIONS: The quality of systematic reviews in dentistry could be improved. If future clinical decisions are to be based upon systematic reviews, it is imperative that reviews address clinically-relevant, focused questions, and follow a transparent, well-designed protocol.

Comment↗

PubMed2001

Transperineal 12-core systematic biopsy in the detection of prostate cancer.

BACKGROUND: The present study was designed to determine the clinical value of transperineal 12-core systematic prostate biopsy guided by transrectal ultrasonography (TRUS) in the detection of prostate cancer. METHODS: A total of 679 consecutive patients underwent systematic prostate biopsies because of abnormal results on digital rectal examination and/or TRUS and/or an elevated serum prostate-specific antigen level. Systematic six- and 12-core biopsies were taken in 138 patients between April 1994 and February 1995 and in the remaining 541 between March 1995 and February 2000, respectively. Twelve-core biopsy included two samples from the lateral portion of the peripheral zone and four from the anterior portion of the transition zone in addition to the conventional six-core biopsy. RESULTS: In the series overall, systematic biopsy revealed 156 cases of prostate cancer (23.0%). The detection rate increased by 5.2%, although this was statistically not significant, from 18.8% (26/138) by six-core biopsy to 24.0% (130/541) by 12-core biopsy. Out of 130 patients in whom prostate cancer was detected by 12-core biopsy, it was supposed that conventional six-core biopsy would have missed 18 cases (13.8%). CONCLUSIONS: Systematic 12-core biopsy might improve the detection rate for prostate cancer. However, further studies are needed to determine its clinical value in the diagnosis of the disease.

Adult↗

PubMed2003

Evaluating systematic reviews and meta-analyses.

Systematic review and meta-analysis procedures make use of explicit methods to methodically search and critically appraise and synthesize the medical care research literature. The methods involve refining a clinical question, designing a search procedure to find eligible studies, and determining the validity of the eligible studies. Independent data extraction by two or more reviewers is preferred. Agreement between the reviewers with respect to relevance and validity should be measured. Meta-analysis procedures estimate an overall average effect from the individual study effects and determine whether these effects appear to measure the same relationship (that is, the studies are not heterogeneous). In the inverse variance method, which is most frequently applied, the overall effect is a weighted average of the individual study effects, where each weight is the inverse of the study variance. To evaluate a systematic review, first determine whether it addresses a question that is relevant to the patients, treatments, and outcomes that are usual in your clinical practice. Then assess the validity of the systematic review, which is reflected by quality of the individual studies, the rigor with which the systematic methods were applied, and the extent of heterogeneity. If the results of the systematic review are valid, then is the effect important enough to make a difference in your clinical practice? Applying the results to an individual patient involves the absolute treatment effect or the number needed to treat, and an awareness of the patient's specific level of risk and personal preferences.

Data Interpretation, Statistical↗

PubMed2004

A brief history of time: the power of botanical systematic reviews.

There are more than 20 completed Cochrane systematic reviews on botanical medicine presently published in the Cochrane Library. There are more than 40 that are planned or in progress. It is an opportune time to explore the information needs of readers of botanical systematic reviews and how those needs can be met better by Cochrane systematic reviews. It is proposed that Cochrane systematic reviews focus not only on efficacy but also on expanded safety and quality. Expanded safety refers not only to the occurrence of adverse events but also the contraindications for use such as drug-herb interactions or allergies to products. Quality pertains to whether or not there was a method of standardizing active ingredients in trials and methods for minimizing risks of contamination. Because there are no package inserts to accompany herbal products as there are for drugs, Cochrane systematic reviews offer the ideal forum to present this much-needed information on expanded safety and quality.

Databases, Bibliographic↗

PubMed1995

Systematic small-area variation in mortality for malignant neoplasms in Sweden 1975-1990.

BACKGROUND: Cancer mortality has been stated to be the best single measure of progress in combatting cancer. The variation in total and cause-specific cancer mortality among health administrative areas in Sweden was analysed in order to find out if the mortality outcome has been equally distributed. METHODS: Data on underlying causes of death for ages 0-74 years were analyzed for the 26 health administrative areas in Sweden, 1975-1990. Analyses of systematic (non-random) variance were performed and measures chosen in order to make comparisons possible between different malignant neoplasms and different periods of time. RESULTS: The systematic variance for all malignant neoplasms was reduced by about 40% during the study period. The largest systematic variations in mortality were found for cancer of the oesophagus and lung, although the systematic variation for these neoplasms was lower in the 1980s than in the 1970s. Large systematic variation was also found for cancer of the cervix uteri and of the bladder. For these causes the variation remained constant throughout the period. CONCLUSIONS: Generally speaking, the outcome of cancer has become more equally distributed across the country. Preventive measures should be possible for the malignant neoplasms with the largest regional variation.

Female↗

PubMed2002

Effects of systematic exposure assessment errors in partially ecologic case-control studies.

BACKGROUND: In ecologic studies, group-level rather than individual-level exposure data are used. When using group-level exposure data, established by sufficiently large samples of individual exposure assessments, the bias of the effect estimate due to sampling errors or random assessment errors at the individual-level is generally negligible. In contrast, systematic assessment errors may produce more pronounced errors in the group-level exposure measures, leading to bias in ecologic analyses. METHODS: We focus on effects of systematic exposure assessment errors in partially ecologic case-control studies. Individual-level information on disease status, group membership, and covariates is obtained from registries, whereas the exposure is a group-level measure obtained from an established exposure database. Effects on bias and coverage of 95% CI in various error situations are investigated under the linear risk model, using both simulated and empirical ecologic data on exposures that are binary at the individual level. RESULTS: Our simulations suggest that the bias produced by systematic exposure assessment errors under the linear risk model is generally approximately equal to the ratio of the slope bias and the intercept bias in ordinary linear regression with measurement errors in the independent variable. Consequently, bias in either direction can occur. Exposure assessment errors that systematically distort the group-level exposure measures have more pronounced effects on bias and coverage than errors producing random fluctuations of the group-level measures, which imply bias towards the null. CONCLUSIONS: The results indicate the need for careful consideration of potential effects of systematic distortions of the group-level exposure measures when constructing and applying group-level exposure databases, such as probabilistic job exposure matrices.

Bias↗

PubMed2005

It's in your hands: the value of handsearching in conducting systematic reviews of public health interventions.

BACKGROUND: While there is an emerging evidence base in public health, the evidence can often be difficult to find. Indexing of journals in MEDLINE has assisted those conducting systematic reviews to more easily identify published studies. However, information technology and the processes associated with indexing are not infallible. Studies may not be correctly marked by study design which may mean they are missed in the electronic searching process. Handsearching for evidence of intervention effectiveness has therefore become a recognized tool in the systematic review process. METHODS: Resources to guide handsearching activity currently are clinically focused, and may not be sensitive to the characteristics of public health studies where study terminology may differ. In response to this issue, the Cochrane Health Promotion and Public Health Field (the Field) developed and implemented a small study to recruit and support handsearchers from around the world to identify health promotion and public health trials and systematic reviews. A strategic framework was developed to recruit and support handsearchers to search six public health-related journals. RESULTS: In total, 131 trials and 21 systematic reviews were identified. The greatest value of handsearching was found to be in supplement editions and abstract sections of journals CONCLUSIONS: The study focused exclusively on indexed journals with the intention that tools and methods developed could be used to explore the potential for handsearching in non-indexed journals and for unpublished studies. The findings from this study will continue to support handsearching efforts and in doing so contribute to high quality systematic reviews of public health interventions.

Health Promotion↗

PubMed2004

Effects of systematic errors in blood pressure measurements on the diagnosis of hypertension.

OBJECTIVE: To estimate the effects of systematic errors in measurements of blood pressure on the diagnosis of hypertension. METHODS: We fitted regression curves to distributions of diastolic and systolic BP from recent Canadian and UK surveys and calculated the effect of systematic measurement errors on changes in the numbers of patients who would be classified hypertensive at thresholds of 85, 90 and 95 mmHg diastolic and 140 and 160 mmHg systolic pressure respectively. RESULTS: Overestimation of diastolic BP by 5 mmHg increases the number of patients whose diastolic BP exceeds 85, 90 and 95 mmHg by 102, 132 and 166% respectively. Equivalent underestimation causes 57, 62 and 67% respectively of hypertensive patients to be missed. If systematic error in diastolic pressure is limited to +/-1 mmHg the diagnosis errors are between -15 and +23%. Overestimation of systolic BP by 3 and 5 mmHg increases the number classified as hypertensive by 24 and 43% respectively. Equivalent underestimation causes 19 and 30% of patients with systolic hypertension to be missed. CONCLUSIONS: Small systematic errors in BP measurements may cause large variations in the proportion of patients diagnosed as hypertensive. To limit over- or under-diagnosis of diastolic hypertension to approximately 20%, systematic errors in diastolic BP measurements should be limited to 1 mmHg. An uncertainty of 3 mmHg may be adequate for detecting systolic hypertension.

Blood Pressure↗

PubMed2002

Effects of systematic nursing instruction of mothers on using medication and on health status of asthmatic children.

The purpose of this study was to investigate the effects of systematic nursing instruction for mothers of children with asthma on their knowledge of the medication, ability to use inhalation devices, self-efficacy of medication use, and on children's health status. A quasi-experimental study was conducted at the Pediatric Allergy Clinic of a major academically based medical center in Taipei, Taiwan. The sample consisted of 82 mothers and their children recruited by purposive sampling. The intervention group (n = 41) received systematic nursing instruction from the researchers and the control group (n = 41) received regular nursing care from staff nurses. The effects of systematic nursing instruction were evaluated two months later using four questionnaires: the mother's knowledge of medication, inhaling steps, self-efficacy of medication use, and child's health status. The results of this study showed that systematic nursing instruction of mothers of children with asthma significantly improved their knowledge of the medication, ability to use inhalation devices, and self-efficacy, as well as decreasing the number of episodes of respiratory disease of children over a two month period. To sum up, these findings demonstrate that systematic nursing instruction of mothers about asthma medication not only benefited mothers directly, but also improved children's health status indirectly.

Adult↗

PubMed2004

Six additional systematic lateral cores enhance sextant biopsy prediction of pathological features at radical prostatectomy.

PURPOSE: We evaluated the contribution of 6 additional systematically obtained, laterally directed biopsy cores to traditional sextant biopsy for the prediction of final pathological findings in the radical prostatectomy specimen. MATERIALS AND METHODS: We studied 178 consecutive patients with no history of prostate biopsy in whom prostate cancer was diagnosed during an initial systematic 12 core biopsy and who subsequently underwent radical prostatectomy. Of the systematic 12 cores we compared the subset of the 6 traditional sextant cores (S6C), the set of 6 laterally directed cores (L6C) and the complete 12 core set, which included the 6 traditional sextant and the 6 laterally directed cores. Biopsy Gleason score, number of positive cores, total cancer length and percent of tumor in the biopsy sets were examined for their ability to predict extracapsular extension, total tumor volume and pathological Gleason score. RESULTS: On univariable analyses the biopsy parameters of the complete 12 core set correlated more strongly with extracapsular extension and total tumor volume than the biopsy parameters of S6C or L6C. On multivariable analyses S6C and L6C were independent predictors of pathological features at prostatectomy. CONCLUSIONS: The addition of 6 systematically obtained, laterally directed cores to traditional sextant biopsy improved the ability to predict pathological features at prostatectomy by a statistically and prognostically significant margin. Preoperative nomograms that use data from a full complement of 12 systematic cores, specifying sextant and laterally directed biopsy cores, should demonstrate improved performance in predicting prostatectomy pathology.

Aged↗

PubMed2004

Systematic relaxation to relieve postoperative pain.

BACKGROUND: Unrelieved pain after surgery can lead to complications, prolonged hospital stay, and delayed recovery. Because of side effects from opioids and differences in response, it is important to use non-pharmacological methods in addition to analgesics to decrease patient discomfort and anxiety. AIMS: We examined the effects of a systematic method of relaxing the body on the sensory and affective components of postoperative pain, anxiety, and opioid intake after initial ambulation. DESIGN: A randomized controlled trial with relaxation and control groups was used. METHOD: The convenience sample of 102 adults underwent abdominal surgery at a large hospital in Thailand. Systematic relaxation was used for 15 minutes during recovery from the first ambulation after surgery. Pain was measured with 100 mm Visual Analogue Sensation and Distress of Pain Scales before and after the intervention. State anxiety was measured before surgery and after the intervention; opioid intake was recorded 6 hours later. RESULTS: The relaxation group had less post-test sensation and distress of pain (26 and 25 mm less, respectively) than the control group (P = 0.001). Relaxation did not result in significantly less anxiety or 6-hour opioid intake. However, group differences in state anxiety were in the expected direction and fewer participants in the relaxation group requested opioids. Nearly all reported that systematic relaxation reduced their pain and increased their sense of control. CONCLUSION: Substantial reductions in the sensation and distress of pain were found when postoperative patients used systematic relaxation. Although tested in Thailand, we recommend that nurses in other countries try systematic relaxation with postoperative patients, in addition to analgesic medication, measuring pain scores and asking about cultural acceptance.

Abdomen↗