SEARCH · PubMed Health

Results for “systematics”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

PubMed2026

"Out of sync and overlooked" - Relationship between social jetlag and anxiety in adolescents: Systematic review and meta-analysis.

Anxiety is the most prevalent mental health difficulty in adolescence, a period characterised by a shift towards an eveningness chronotype that is not aligned with societal demands (i.e., school start times). Experiencing "social jetlag" (SJL), a discrepancy in weekday-weekend sleep timing, is proposed to be associated with increased anxiety. A PRISMA-compliant systematic review and meta-analysis was conducted to investigate the relationship between SJL and anxiety in adolescents (age range: 12-18 years). Systematic searches were conducted in PsycINFO, Web of Science, Embase, PubMed, MEDLINE, and ProQuest Dissertations & Theses Global on 14th November 2024 to retrieve empirical studies analysing the relationship between SJL and anxiety in 12-18-year-olds. A multi-level random-effect meta-analysis was conducted in R to estimate the magnitude of the association between SJL and anxiety. After screening 2,138 records, 18 studies were included in the systematic review, with 12 included in the meta-analysis (235,526 participants in total) and six in a narrative review. A small association was found between increased SJL and more severe anxiety (Fisher's z = 0.0614, 95% CI [0.0268, 0.0961], p = 0.0011). These findings highlight the importance of addressing behavioural strategies targeting healthy regular sleep as a tool to improve mental health in adolescence.

Adolescent↗

PubMed2005

Storylines of research in diffusion of innovation: a meta-narrative approach to systematic review.

Producing literature reviews of complex evidence for policymaking questions is a challenging methodological area. There are several established and emerging approaches to such reviews, but unanswered questions remain, especially around how to begin to make sense of large data sets drawn from heterogeneous sources. Drawing on Kuhn's notion of scientific paradigms, we developed a new method-meta-narrative review-for sorting and interpreting the 1024 sources identified in our exploratory searches. We took as our initial unit of analysis the unfolding 'storyline' of a research tradition over time. We mapped these storylines by using both electronic and manual tracking to trace the influence of seminal theoretical and empirical work on subsequent research within a tradition. We then drew variously on the different storylines to build up a rich picture of our field of study. We identified 13 key meta-narratives from literatures as disparate as rural sociology, clinical epidemiology, marketing and organisational studies. Researchers in different traditions had conceptualised, explained and investigated diffusion of innovations differently and had used different criteria for judging the quality of empirical work. Moreover, they told very different over-arching stories of the progress of their research. Within each tradition, accounts of research depicted human characters emplotted in a story of (in the early stages) pioneering endeavour and (later) systematic puzzle-solving, variously embellished with scientific dramas, surprises and 'twists in the plot'. By first separating out, and then drawing together, these different meta-narratives, we produced a synthesis that embraced the many complexities and ambiguities of 'diffusion of innovations' in an organisational setting. We were able to make sense of seemingly contradictory data by systematically exposing and exploring tensions between research paradigms as set out in their over-arching storylines. In some traditions, scientific revolutions were identifiable in which breakaway researchers had abandoned the prevailing paradigm and introduced a new set of concepts, theories and empirical methods. We concluded that meta-narrative review adds value to the synthesis of heterogeneous bodies of literature, in which different groups of scientists have conceptualised and investigated the 'same' problem in different ways and produced seemingly contradictory findings. Its contribution to the mixed economy of methods for the systematic review of complex evidence should be explored further.

Diffusion of Innovation↗

PubMed2005

Stroke prevention with aspirin, warfarin and ximelagatran in patients with non-valvular atrial fibrillation: a systematic review and meta-analysis.

OBJECTIVE: To compare the effectiveness of aspirin, warfarin, and ximelagatran as thromboprophylaxis in patients with non-valvular atrial fibrillation (NVAF). METHODS: Systematic review of randomised controlled trials in patients with NVAF treated with adjusted-dose warfarin and aspirin, fixed low-dose (FLD) warfarin, ximelagatran or placebo. Outcome measures studied were ischaemic stroke, systemic embolism, mortality and haemorrhage. Meta-analysis was performed using a fixed effects model. RESULTS: We identified 13 trials (n=14,423 participants) of sufficient quality to be included in the analysis. Adjusted-dose warfarin significantly reduced the risk of ischaemic stroke or systemic embolism compared with aspirin (relative risk [RR] 0.59; 95% confidence interval [CI]: 0.40 to 0.86), FLD warfarin (RR 0.36; 95% CI: 0.23 to 0.58), or placebo (RR 0.33; 95% CI: 0.24 to 0.45). However, aspirin and placebo had a lower risk of major bleeding compared to warfarin (RR 0.58; 95% CI: 0.35 to 0.97 and RR 0.45; 95% CI: 0.25 to 0.82, respectively). The oral direct thrombin inhibitor, ximelagatran was as effective as adjusted-dose warfarin in the prevention of ischaemic strokes or systemic emboli (RR 1.04; 95% CI: 0.77 to 1.40) with less risk of major bleeding (RR 0.74; 95% CI: 0.56 to 0.96). Adjusted-dose warfarin significantly reduced mortality compared to placebo (RR 0.69; 95% CI: 0.53 to 0.89), but not for any of the other comparisons (aspirin: RR 0.87; 95% CI: 0.67 to 1.13; FLD warfarin: RR 1.11; 95% CI: 0.81 to 1.52; ximelagatran: RR 1.04; 95% CI: 0.86 to 1.26). CONCLUSIONS: We have extended previous analyses, making this the largest systematic review and meta-analysis of thromboprophylaxis trial data in AF--and have included recent trials with the new oral direct thrombin inhibitor, ximelagatran. This systematic review confirms the superiority of anticoagulation therapy over aspirin as thromboprophylaxis in patients with NVAF. The new oral direct thrombin inhibitor, ximelagatran, appears as effective as adjusted-dose warfarin for the prevention of thromboembolic events in NVAF, with a lower risk of bleeding.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2005

Systematic review as an evidence-based tool for the operating room.

THIS ARTICLE DETAILS advantages of using systematic reviews (ie, meta-analyses) to determine evidence-based best practices. A NUMBER OF SYSTEMATIC REVIEWS relevant to the OR and produced under the auspices of the Cochrane Collaboration are explored with the aim of encouraging perioperative nurses to become familiar with, if not part of, the process of systematic review development.

Evidence-Based Medicine↗

PubMed2000

Depression after stroke and lesion location: a systematic review.

BACKGROUND: There is conflicting evidence on the hypothesis that the risk of depression after stroke is influenced by the location of the brain lesion. We undertook a systematic review to examine the hypotheses that depression is more commonly associated with left-hemisphere strokes than with right-hemisphere strokes and with lesions of the left anterior brain than with other regions. METHODS: We did a computer-aided search of MEDLINE, BIDS ISI, and PsychLit databases supplemented by hand searches of key journals. We included all reports on the association of depression after stroke with the location of the brain lesion. Studies were systematically and independently examined by two investigators. Fixed-effects and random-effects meta-analyses were done. FINDINGS: 143 reports were identified by the search strategy. 48 were eligible for inclusion. Not all reports included original data. Only two reports of original data supported the hypotheses and seven clearly did not. The pooled (random-effects) relative risk of depression after a left-hemisphere stroke, compared with a right-hemisphere stroke, was 0.95 (95% CI 0.83-1.10). For depression after a left anterior lesion compared with all other brain areas the pooled (random-effects) relative risk was 1-17 (0.87-1.62). Restriction of the analyses to reports from high-quality studies or major depressive disorder did not substantially affect the findings. Nor were they affected by stratification of the time between stroke and the assessment of depression. Multiple publications from the same samples of patients were apparent. INTERPRETATION: This systematic review offered no support for the hypothesis that the risk of depression after stroke is affected by the location of the brain lesion.

Aphasia↗

PubMed2005

[Primary vesicoureteral reflux treatment in childhood: comparsion of two systematic review].

UNLABELLED: Many medical practices are being carried out unawares of their efficiency, or of their actual impact on the health of the patients, therefore it is necessary to consider the support of professional recommendations with scientific evidence. THE PRIMARY OBJECTIVE: To perform a systematic review (SR) of the therapeutic management of primary VUR in pediatric urology. MATERIAL AND METHODS: A systematic review has been performed, including scientific evidence-based medicine criteria, of the articles published in all of the available databases. Inclusion criteria concerning basic quality of the articles were considered essential, as well as exclusion criteria to be able to reject the articles. RESULTS AND DISCUSSION: Subsequently, and following the critic reading of greater than 320 articles, statistical study of the grouped data was performed according to the type of treatment and to the benefits contributed by each treatment, and also to their undesirable effects. Finally we have made a comparison between our results and recent Cochrane Systematic Review. The following Conclusions were drawn from the results obtained and from the analysis of the texts. Both medical and surgical treatment present with similar effectiveness concerning resolution of grades I, II and III of VUR, and the former one is the recommended initial treatment following diagnosis. Endoscopic treatment is exactly as effective as open surgery for grades I, II and III with fewer undesirable effects secondary. There are no differences concerning the efficacy of the different injected substances. Not enough evidences exist for degrees IV and V that may recommend or advise against any of the treatments. In any degree of VUR, open surgical treatment is superior as far as medical treatment is concerned only regarding the number of acute pyelonephritis episodes during followup. This conclusion cannot be applied on endoscopic treatment.

Child↗

PubMed2002

Pharmacological treatments for acute migraine: quantitative systematic review.

We wanted to compare the analgesic efficacy and adverse effects of pharmacological treatments for acute migraine through a systematic review of randomised controlled trials in patients with acute migraine pain of moderate to severe intensity. Trials were identified from systematic searching of bibliographic databases. For eletriptan information from all trials was supplied by Pfizer Inc. Outcomes sought were headache relief at 1 and 2h, patients pain free at 2h and sustained relief over 24h for treatments compared with placebo. Numbers-needed-to-treat (NNTs) were calculated, together with relative benefit. Information on adverse effects was also collected. Comparisons of relative efficacy used the same definition of headache, the same degree of pain at the start of treatment and the same definitions of outcomes, and always compared with placebo. Forty-eight publications reporting on 54 trials were included in the meta-analyses, with 79 placebo comparisons for the primary outcome of headache relief at 2h. Information on any outcome was available for nine oral medications, two intranasal medications and subcutaneous sumatriptan in 21,022 patients. For headache relief at 2h NNTs ranged from 2.0 for subcutaneous sumatriptan 6mg to 5.4 for naratriptan 2.5mg. For patients pain free at 2h NNTs ranged from 2.1 for subcutaneous sumatriptan 6mg to 8.6 for aspirin 900mg plus metoclopramide 10mg. For sustained relief over 24h NNTs ranged from 2.8 for eletriptan 80mg to 8.3 for rizatriptan 5mg. It was not possible to systematically review adverse effects data. Most interventions are effective. There is considerable information on relative efficacy for a number of outcomes.

Acute Disease↗

PubMed2003

How often do patients with psychosis fail to adhere to treatment programmes? A systematic review.

BACKGROUND: Studies that assess the rates of psychotic patients who fail to adhere to treatment programmes have generated heterogeneous results, with estimates ranging from 24 to 90%. This paper presents findings from a systematic review on adherence to treatment by patients with psychosis. Its purpose is to provide an overall estimate of treatment non-adherence in community psychiatric services, and to analyse and study patient characteristics explaining the between-study heterogeneity in rates of non-adherence. METHOD: A systematic review of published studies that report rates of non-adherence with medication and scheduled appointments by psychotic patients in community settings has been undertaken. RESULTS: A total of 103 studies were included in this systematic review. Eighty-six of these studies were suitable for data re-analysis. The overall weighted mean rate of non-adherence, calculated in a sample of 23 796 patients, was 25.78%. A linear regression analysis of non-adherence rates on background characteristics showed that sample size was negatively associated with non-adherence rates, while first-contact cases and low-adherence cases, in comparison with ongoing cases, were associated with higher non-adherence rates. Factors associated with poor compliance included: lack of insight; positive symptoms; younger age; male gender; history of substance abuse; unemployment; and low social functioning. CONCLUSIONS: Approximately one in four patients with psychosis fails to adhere with treatment programmes. Preventive evidence-based clinical interventions should be routinely implemented in community settings to reduce patient non-adherence.

Antipsychotic Agents↗

PubMed2004

Systematic review of the role of gender as a health determinant of hospitalization for depression.

OBJECTIVES: To conduct a systematic review of selected health determinants, including gender, and their impact on hospitalization rates for depression. Depression includes both depressive and bipolar disorders. Selected health determinants were gender, age, sex, family structure, education, and socioeconomic status. METHODS: Systematic search of conventional and fugitive literature sources. All reports of primary data, systematic reviews, and meta-analysis of primary data were included if they focused on hospitalization for depression and reported data by one or more of the selected health determinants. Two researchers independently evaluated each citation for inclusion and extracted data from the included studies. RESULTS: There is an important underreporting of health determinants data in studies of hospitalization for depression. No studies examined the role of gender. Age and sex were reported in 83 percent and 80 percent of the 110 included studies. Women showed a higher rate of hospitalization for depression than men (p < .05). Age and diagnosis had different effects in men and women. Adult women were significantly more likely than men to report a depressive disorder, whereas men were more likely to report a bipolar disorder (p < .05). Little can be concluded on the other health determinants. CONCLUSIONS: The importance of reporting hospitalization data and conducting hospital utilization analysis by sex and health determinants, including gender, must be emphasized.

Age Factors↗

PubMed2005

Effects of continuing medical education on improving physician clinical care and patient health: a review of systematic reviews.

OBJECTIVES: The objective of physician continuing medical education (CME) is to help them keep abreast of advances in patient care, to accept new more-beneficial care, and discontinue use of existing lower-benefit diagnostic and therapeutic interventions. The goal of this review was to examine effectiveness of current CME tools and techniques in changing physician clinical practices and improving patient health outcomes. METHODS: Results of published systematic reviews were examined to determine the spectrum from most- to least-effective CME techniques. We searched multiple databases, from 1 January 1984 to 30 October 2004, for English-language, peer-reviewed meta-analyses and other systematic reviews of CME programs that alter physician behavior and/or patient outcomes. RESULTS: Twenty-six reviews met inclusion criteria, that is, were either formal meta-analyses or other systematic reviews. Interactive techniques (audit/feedback, academic detailing/outreach, and reminders) are the most effective at simultaneously changing physician care and patient outcomes. Clinical practice guidelines and opinion leaders are less effective. Didactic presentations and distributing printed information only have little or no beneficial effect in changing physician practice. CONCLUSIONS: Even though the most-effective CME techniques have been proven, use of least-effective ones predominates. Such use of ineffective CME likely reduces patient care quality and raises costs for all, the worst of both worlds.

Clinical Competence↗

PubMedDate not supplied

[Systematic review of the role of service users as researchers in mental health studies].

AIMS: Service user involvement in mental health service development and research is becoming more common in countries like the UK, USA and Canada. This systematic review of the international scientific literature has been carried out to assess the stage of development of mental health service users involvement in research. METHOD: Systematic review of any research project actively involving service users in any part of the research process. RESULTS: Thirty-five studies met the inclusion and exclusion criteria and were included in the systematic review. Nine studies used quantitative techniques, 24 used qualitative techniques and two studies used both quantitative and qualitative techniques. While three studies were user-led, in three other studies the users were simply consulted but did not have any active role in the research. The remaining 29 studies were based on a collaboration between service users and professional researchers. CONCLUSIONS: The involvement of mental health service users in the research process is feasible both in quantitative and qualitative research studies. The involvement of service users in research has a number of benefits; such research requires more accurate planning and more time than the traditional research.

Biomedical Research↗

PubMed1997

Do authors of review articles use systematic methods to identify, assess and synthesize information?

PURPOSE: Review articles are an important source of summary information for practising clinicians to assist them in remaining current with the rapidly expanding medical literature. Consequently it is essential that these be of the highest quality. In this study we evaluate, according to published criteria, the methodological quality of review articles (R) including meta-analysis (MA) appearing in a major cancer journal, Journal of Clinical Oncology (JCO), 1983-1995. METHODS: A hand-search of JCO was performed, from the first issue January 1983 through December 1995, to identify R, defined as publications that describe and comment on studies relevant to a specific topic or clinical intervention. Only those dealing with aspects of treatment of human cancer were considered further. Methodological quality was first assessed using 8 criteria proposed by Mulrow, rated independently by two medical oncologists as: specified, unclear or not specified. MA, including studies of dose intensity, were further analyzed according to 23 more detailed criteria proposed by Sacks et al. and rated as adequate, partial or no/unknown compliance. RESULTS: Of 176 review articles, 122 dealt with aspects of treatment of cancer. Compliance with four of Mulrow's eight criteria was generally good, in that 99% clearly stated a purpose, all attempted qualitative synthesis of data. 95% presented a summary and 76% considered future directions. However, in the 106 qualitative reviews (QR), authors rarely gave information on methods of data identification (11.3%), data selection (10.4%) and assessment of validity (8.4%). Structured abstracts seemed to improve the focus and clarity of QR and there was a minor improvement in deficient areas in the later time cohort (1990-1995). Based on 'adequate' compliance with each of the 23 criteria identified by Sacks et al., six dose intensity studies scored 7-12, seven literature data MA scored 10-15 and three individual patient data MA scored 16-18. The highest scores were in the sections relating to prospective design, combinability and statistical analysis. Factors relating to control of bias, sensitivity analysis and application of results were addressed less consistently. CONCLUSIONS: With the exception of MA, the majority of authors contributing reviews to a major cancer journal, JCO, did not use systematic methods to identify, assess and synthesize information. Initiatives such as the Cochrane Collaboration Cancer Network can support and educate clinicians who wish to perform systematic reviews, but quality of reviews would also improve if author, editors and readers systematically applied any of the sets of criteria now available in the literature.

Humans↗

PubMed2002

A systematic review of the survival of implants in bone sites augmented with barrier membranes (guided bone regeneration) in partially edentulous patients.

The aim of the present systematic review was to assess the survival of implants in regenerated bone applying the method of guided bone regeneration (GBR) compared with the survival of implants in non-regenerated bone. Studies to be included in this review needed to provide at least 12-month results following prosthetic reconstruction of titanium implants in bone regenerated by GBR with or without membrane supporting materials. The outcome measures were implant survival described as presence of implant, implant success (according to the criteria in the respective study), absence of clinical implant mobility, absence of implant fracture, absence of progressive peri-implant crestal bone loss as assessed on radiographs without clinical signs of peri-implant infection, absence of peri-implant infection with suppuration. A MEDLINE search and a hand search of relevant scientific journals were conducted including studies from the year 1990 to May 2001. A total of 11 studies could be identified fulfilling the inclusion criteria. All studies except two had the characteristics of case series or cross-sectional surveys. The two different studies had both test and control implants included in their analysis and qualified as controlled clinical trials. Cumulative success or survival rates, respectively, for implants in regenerated bone ranged from 100% after 5 years to 79.4% after 5 years of function. Regarding survival data, no significant differences were found in the controlled clinical trials between implants in regenerated compared to implants in non-regenerated bone. Within the limits of this systematic review characterized by second and third levels of evidence, the following conclusions can be drawn: The survival rate of implants placed into sites with regenerated/augmented bone using barrier membranes varied between 79% and 100% with the majority of studies indicating more than 90% after at least one year of function. The survival rates obtained in the present systematic review are similar to those generally reported for implants placed conventionally into sites without the need for bone augmentation.

Adult↗

PubMed2002

A guide to systematic reviews.

Systematic reviews have become widely used for evaluating evidence across all fields of biomedicine. The objective of a systematic review is to provide a comprehensive and contemporary appraisal of research using transparent methods whilst aiming to minimize bias. In essence, research methodology is employed in the conduct of the review. Such reviews are therefore fundamentally different from traditional 'narrative' review articles in their purpose and in their potential to aid clinical decision-making. This paper is a guide to the rationale and nature of systematic reviews and will provide a background to understanding their use in clinical practice.

Dental Research↗

PubMed2004

Psychosocial interventions for patients with advanced cancer - a systematic review of the literature.

Advanced cancer is associated with emotional distress, especially depression and feelings of sadness. To date, it is unclear which is the most effective way to address these problems. This review focuses on the effects of psychosocial interventions on the quality of life (QoL) of patients with advanced cancer. It was hypothesised that patients will benefit from psychosocial interventions by improving QoL, especially in the domain of emotional functioning. The review was conducted using systematic review methodology involving a systematic search of the literature published between 1990 and 2002, quality assessment of included studies, systematic data extraction and narrative data synthesis. In all, 10 randomised controlled studies involving 13 trials were included. Overall interventions and outcome measures across studies were heterogeneous. Outcome measures, pertaining to the QoL dimension of emotional functioning, were most frequently measured. A total of 12 trials evaluating behaviour therapy found positive effects on one or more indicators of QoL, for example, depression. The results of the review support recommendation of behaviour therapy in the care of patients with advanced cancer.

Clinical Trials as Topic↗

PubMed2006

Interventions to prevent obesity in children and adolescents: a systematic literature review.

OBJECTIVE: Preventive measures to contain the epidemic of obesity have become a major focus of attention. This report reviews the scientific evidence for medical interventions aimed at preventing obesity during childhood and adolescence. DESIGN: A systematic literature review involving selection of primary research and other systematic reviews. Articles published until 2004 were added to an earlier (2002) review by the Swedish Council on Technology Assessment in Health Care. METHODS: Inclusion criteria required controlled studies with follow-up of at least 12 months and results measured as body mass index, skinfold thickness or the percentage of overweight/obesity. Children could be recruited from normal or high-risk populations. RESULTS: Combining the new data with the previous review resulted in an evaluation of 24 studies involving 25 896 children. Of these, eight reported that prevention had a statistically significant positive effect on obesity, 16 reported neutral results and none reported a negative result (sign test; P=0.0078). Adding the studies included in five other systematic reviews yielded, in total, 15 studies with positive, 24 with neutral and none with negative results. Thus, 41% of the studies, including 40% of the 33 852 children studied, showed a positive effect from prevention. These results are unlikely to be a random chance phenomenon (P=0.000061). CONCLUSION: Evidence shows that it is possible to prevent obesity in children and adolescents through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity.

Adolescent↗

PubMed2000

High dose methylprednisolone in the management of acute spinal cord injury - a systematic review from a clinical perspective.

STUDY DESIGN: Systematic literature review for primary data using predefined inclusion, exclusion and validity criteria. Primary outcome measure was standardised neurological examination or neurological function. Secondary outcomes; acute mortality, early morbidity. OBJECTIVES: To access the literature available to clinicians systematically and evaluate the evidence for an effect of high dose methylprednisolone (MPSS) on neurological improvement following acute spinal cord injury (ACSI). METHODS: Information retrieval was based on Medline search (1966 through December 1999) using the strategy 'spinal cord injury' and 'methylprednisolone' (or 'dexamethasone') with no other restrictions. Primary data publications using high dose steroids given within 12 h following spinal cord injury and reporting outcome measures separately for steroid and non-steroid treated groups were selected. Evaluation followed the guides of Guyatt et al7 (for the Evidence Based Working Group in Canada). Studies with questionable validity were excluded. Level of evidence and treatment recommendation utilised the Canadian Task Force on the Periodic Health Examination criteria.6 Experimental spinal cord injury studies on larger animals were included; small mammal experiments were considered beyond evaluation. RESULTS: Three clinical trials and six cohort study publications were found to satisfy the review criteria. The evidence they provide supports 'the recommendation that the manoeuvre (high dose methylpredisolone) be excluded from consideration as an intervention for the condition'10 (acute spinal cord injury). Twelve larger animal publications were detailed. Validity and the functional significance of results was of concern in many. The weight of evidence lay with those studies demonstrating no definite effect of MPSS on functional outcome. In cat experiments with higher level cord damage, deaths in the MPSS treated groups were notable. CONCLUSION: The evidence produced by this systematic review does not support the use of high dose methylprednisolone in acute spinal cord injury to improve neurological recovery. A deleterious effect on early mortality and morbidity cannot be excluded by this evidence.

Acute Disease↗

PubMed2000

Systematic review and meta-analysis in anatomic pathology.

Systematic reviews and meta-analyses are techniques of data retrieval and analysis which complement traditional narrative reviews. They are widely used in clinical medicine and are finding an increasing role in anatomical pathology. Performing high quality systematic review and meta-analysis requires the accumulation of large numbers of cases from well planned and executed studies and is facilitated if data is presented in a standardized manner. Techniques which allow data from individual patients included in a variety of different studies are now being developed indicating that in future research papers may require a more detailed description of results than in the past. This need may be met by posting anonymised data on the Internet. Systematic reviews and meta-analyses are never complete since data are continually contributed and analyses constantly updated. As with any research paper, the results of these techniques require careful evaluation and the role of the expert reviewer is enlarged by these methodologies.

Humans↗