《中国循证儿科杂志》发表的干预类系统评价/Meta分析报告质量评价

目的 评价中文儿科学科循证医学杂志发表的干预类系统评价/Meta分析的报告质量。方法 检索创刊之日起至2011年12月31日《中国循证儿科杂志》和Pediatrics公开发表的干预类系统评价/Meta分析,收集待评价文献的基本信息,采用系统综述和Meta分析优先报告的条目(PRISMA)量表进行评价。使用Review Manager 5.2、Meta-Analyst软件进行统计分析。结果 共纳入文献67篇。《中国循证儿科杂志》和Pediatrics分别为30篇和37篇。PRISMA量表评分最高24.5分,最低12.0分,平均（19.98±2.86）分。PRISMA发布前后,系统评价/Meta分析的报告质量差异无统计学意义。作者人数对系统评价/Meta分析的报告质量影响不显著。系统评价/Meta分析报告质量,有基金资助优于无基金资助,作者单位数量＜2个优于作者单位数量≥2个,来自医院的作者优于来自研究机构,中文文献高于英文文献。PRISMA得分《中国循证儿科杂志》高于Pediatrics;《中国循证儿科杂志》66.7%的文献PRISMA得分集中在高质量分数段~27分,无低质量文献,Pediatrics 70.3%的文献PRISMA得分集中在中等质量分数段~21分,低质量文献占13.5%。结论 《中国循证儿科杂志》在理解和执行系统评价和Meta分析写作规范的努力是值得肯定的,进一步提高报告质量和规范发表还有很大空间。鉴于纳入评价的杂志和文献数较少,推而广之到儿科学杂志PRISMA评价报告质量还缺乏信心。     

Recent clinical trials of surfactant treatment for neonates

OBJECTIVE: To search for recent clinical trials of neonatal surfactant treatment and report their findings. METHODS: Recent was defined as published between 2000 and 2005. An online search on PubMed was made on 30th December 2005 using the following terms: surfactant treatment, clinical trials and neonate, with limits of years 2000 to 2005 and age - newborn from birth to 1 month. Randomised clinical trials (RCTs) and systematic reviews of RCTs were prioritised and studies in children and animals were excluded from further analysis. RESULTS: 175 papers were found in this search. Only about half of these papers were directly related to some aspect of surfactant treatment and of these just over one-half were either RCTs or systematic reviews of RCTs. Of the 34 RCTs of surfactant treatment, 3 were excluded as they involved children or animals rather than neonates. Twenty-nine trials studied preterm babies with respiratory distress syndrome (RDS) and 2 were for meconium aspiration syndrome (MAS) in term infants. The median sample sizes of these studies were RDS (92, range 19-1,361) and MAS (42, range 22-61). Eighteen of the RDS trials compared two or more surfactant preparations, the most frequently studied being Curosurf and Survanta but altogether 11 different surfactants were compared. These new RCTs need to be analysed by meta-analyses in systematic reviews. Twelve systematic reviews were found and these demonstrated the superiority of prophylactic over selective use of surfactant in babies <30 weeks, natural over synthetic surfactant and the absence of an increase in long-term developmental sequelae. Surfactant for MAS may reduce the severity of respiratory illness and the need for extracorporeal membrane oxygenation. Of the non-randomised trials' novel delivery methods, failure to use evidence-based guidelines and the benefit of surfactant for babies <25 weeks were the most interesting. CONCLUSIONS: Surfactant remains one of the most effective and safest interventions in neonatology. Prophylactic natural surfactant seems to be the most evidence-based treatment for babies <30 weeks. Of the newer synthetic surfactants, only Surfaxin has been compared with currently used surfactants and systematic reviews are needed to establish if it has a role in treatment of RDS.The improvement in outcome for babies <25 weeks has been due to a number of interventions: prenatal steroids, prenatal antibiotics and postnatal surfactant. Clinical trials of surfactant replacement in the neonate continue to be published with remarkable frequency.     

Cerebral edema in diabetic ketoacidosis.

OBJECTIVE: To review the causes of cerebral edema in diabetic ketoacidosis (CEDKA), including pathophysiology, risk factors, and proposed mechanisms, to review the diagnosis, treatment, and prognosis of CEDKA and the treatment of diabetic ketoacidosis as it pertains to prevention of cerebral edema. DATA SOURCE: A MEDLINE search using OVID was done through 2006 using the search terms cerebral edema and diabetic ketoacidosis. RESULTS OF SEARCH: There were 191 citations identified, of which 150 were used. An additional 42 references listed in publications thus identified were also reviewed, and two book chapters were used. STUDY SELECTION: The citations were reviewed by the author. All citations identified were used except 25 in foreign languages and 16 that were duplicates or had inappropriate titles and/or subject matter. Of the 194 references, there were 21 preclinical and 40 clinical studies, 35 reviews, 15 editorials, 43 case reports, 29 letters, three abstracts, six commentaries, and two book chapters. DATA SYNTHESIS: The data are summarized in discussion. CONCLUSIONS: The causes and mechanisms of CEDKA are unknown. CEDKA may be due as much to individual biological variance as to severity of underlying metabolic derangement of the child's state and/or treatment risk factors. Treatment recommendations for CEDKA and diabetic ketoacidosis are made taking into consideration possible mechanisms and risk factors but are intended as general guidelines only in view of the absence of conclusive evidence.     

Secular trends in impact factor of neonatology publications over a 10-year period

Aim: To test the hypotheses that published randomized clinical trials (RCTs) in neonatology with negative results (NR) are more likely to be published in journals with lower impact factor (IF) than those with positive results (PR); that there is an increase in the number of yearly published RCTs; that studies with large sample sizes are likely to be published in journals with higher IF. Methods: We used all English‐written RCTs registered in MEDLINE between 1/1/2001–31/12/2010 in the field of neonatology. Each RCT was classified as having a PR or NR. IF of each journal was determined for the year of publication. Results: We identified 329 RCTs. Yearly number of RCTs varied between 19 and 46, with no significant consistent linear increase over the years. There was no significant change over the years in average IF or in average patient size. IF and sample size of the studies were not significantly higher in studies with PR than in studies with NR. Conclusion: The number of RCTs per year in the field of neonatology has stabilized in the past 10 years, and RCTs with positive or negative results are published in journals of similar IF.     

Practitioner review: Self-harm in adolescents

Background: Repeated self‐harm in adolescents is common and associated with elevated psychopathology, risk of suicide, and demand for clinical services. Despite recent advances in the understanding and treatment of self‐harm there have been few systematic reviews of the topic. Aims: The main aim of this article is to review randomised controlled trials (RCTs) reporting efficacy of specific pharmacological, social or psychological therapeutic interventions (TIs) in reducing self‐harm repetition in adolescents presenting with self‐harm. Method: Data sources were identified by searching Medline, PsychINFO, EMBASE, and PubMed from the first available year to December 2010. RCTs comparing specific TIs versus treatment as usual or placebo in adolescents presenting with self‐harm were included. Results: Fourteen RCTs reported efficacy of psychological and social TIs in adolescents presenting with self‐harm. No independently replicated RCTs have been identified reporting efficacy of TIs in self‐harm reduction. Developmental Group Psychotherapy versus treatment as usual was associated with a reduction in repeated self‐harm, however, this was not replicated in subsequent studies. Multisystemic Therapy (MST) versus psychiatric hospitalisation was associated with a reduction of suicidal attempts in a sample of adolescents with a range of psychiatric emergencies. However, analyses focusing only on the smaller subgroup of adolescents presenting with deliberate self‐harm at the initial psychiatric emergency, did not indicate significant benefits of MST versus hospitalisation. Conclusions: Further research is urgently needed to develop TIs for treating self‐harm in adolescents. MST has shown promise but needs to be evaluated in a sample of adolescents with self‐harm; dialectic behavioural therapy and cognitive behavioural therapy for self‐harm require RCTs to evaluate efficacy and effectiveness.     

中国儿科领域随机对照试验报告质量横断面调查

摘要目的评估CONSORT声明自1997年引入中国以来,中国儿科杂志发表RCT的报告质量是否得到提高。方法手工检索中国大陆被中国科学引文数据库（CSCD）收录的6种国内儿科杂志（《中华儿科杂志》、《中华小儿外科杂志》、《中国当代儿科杂志》、《中国实用儿科杂志》、《中国循证儿科杂志》和《临床儿科杂志》）,检索时间均为创刊至2010年12月。对照CONSORT声明的评价条目清单,设计标准的资料提取表格,评估纳入文献的报告质量,使用SPSS 18.0软件进行统计分析。结果619篇RCT文献进入分析。1997至2010年与1997年前发表的RCT相比,其在文题、摘要、引言、受试者招募、基线资料和辅助分析等方面的报告质量有一定的改善（P<0.05）,但在方法学的报告方面存在报告不充分或不准确的问题,如确定样本量的方法（0.6% vs 1.1%）、随机序列产生的方法（3.2% vs 7.6%）、分配隐藏（0 vs 1.1%）、盲法（0 vs 2.6%）等。进一步对稿约中要求CONSORT声明的《中国循证儿科杂志》发表的9篇RCT进行评估,其CONSORT条目符合率均高于其他儿科杂志,特别在方法学的报告方面,如确定样本量的方法、随机序列产生的方法、分配隐藏和盲法等。结论总体而言,CONSORT声明的引入并没有使中国儿科领域RCT的报告质量从根本上提高。在稿约中要求CONSORT声明的杂志可显著提高RCT的报告质量。     

甲强龙在儿童体外循环辅助下心脏手术中应用价值的系统评价和Meta分析

目的 评估儿童体外循环辅助下心脏手术围术期应用甲强龙的价值。 方法 纳入体外循环辅助下行心脏手术年龄＜16岁的患儿、英文RCT、试验组预防性应用甲强龙、对照组为安慰剂或空白对照的文献。检索PubMed、Embase、Medline和 Cochrane图书馆数据库,以PubMed为例,检索式：methylprednisolone AND cardiopulmonary bypass OR CPB。检索时间均为建库至2016年5月13日。主要结局指标为术后出院时病死率,并根据甲强龙给药方式（术前静脉给药和术中膜肺给药）行分层分析。采用Cochrane协作网推荐的偏倚风险评估工具评价文献质量。 结果 系统检索后6篇文献中的486例体外循环辅助下心脏手术患儿进入本文分析,其中甲强龙组253例,对照组233例。5篇文献描述了随机序列产生方法,2篇文献采用了分配隐藏,6篇文献均采用了盲法并描述了脱落或失访,5篇文献未选择性报告研究结果,其他偏倚来源均为不确定。2篇静脉给药的文献术后病死率为 9.6%（13/135）,甲强龙组与对照组术后病死率［1.5%（2/67）vs 81%(11/68）］,差异有统计学意义（固定效应模型,RR =0.22,95%CI：0.06~0.83,P=0.03）。次要结局指标中体外循环（CPB ）时间（固定效应模型,MD=－10.67,95% CI：－17.82~－3.53,Ｐ=0.003）和术前静脉给药亚组ICU住院时间（固定效应模型,MD=－0.72,95%CI：－1.33~－0.12,P=0.02）与对照组比较差异均有统计学意义。术中膜肺给药亚组ICU住院时间以及甲强龙组机械通气时间和阻断时间与对照组比较差异均无统计学意义。 结论 在有限证据下,儿童体外循环辅助下心脏手术围术期预防性静脉使用甲强龙可降低术后病死率,术前静脉给药可以缩短CPB时间和ICU住院时间。     

Research in neonatology for the 21st century: executive summary of the National Institute of Child Health and Human Development-American Academy of Pediatrics workshop. Part I: academic issues

This article presents the executive summary of the presentations and discussions at the Workshop on Research in Neonatology sponsored by the National Institute of Child Health and Human Development and the American Academy of Pediatrics Section on Perinatal Pediatrics convened in January 2004. In this article, the scientific aspects are summarized, highlighting the current knowledge gaps and identifying research priorities with a focus on emerging technologies. In a separate article, issues concerning workforce needs and shortages and board-certification requirements are presented. Full-length articles on the presented topics will be published in the Journal of Perinatology.     

Neonatal polycythaemia: critical review and a consensus statement of the Israeli Neonatology Association

The aim of this paper is to critically review neonatal polycythaemia (NP) literature, in terms of definition, diagnosis and management. We reviewed all Medline articles on NP up to December 2009. (i) The textbook definition of NP [venous haematocrit (HCT) > 65%] is empirical and not based on statistical definition, symptoms or complications. (ii) Measurement of viscosity is not better than HCT in predicting complications. (iii) Normovolaemic NP because of increased erythropoiesis may be different from hypervolaemic polycythaemia because of excessive foetal transfusion. (iv) Coexisting hypoglycaemia may worsen long-term outcome. (v) Four clinical trials (CTs) studied partial exchange transfusion (PET) on outcomes. In all trials, PET was performed after 6 h of life. There is no evidence that PET improves neurodevelopmental outcome of asymptomatic NP, and it might increase the risk of necrotizing enterocolitis. These CTs have inherent design flaws: (a) CNS 'damage' may occur before PET. (b) Confounding variables that may affect outcome have not been studied. (vi) If PET is performed, normal saline is the best alternative. (vii) The long-term effect of PET on symptomatic infants has not been studied. Conclusion: Current definition and management of NP are little evidence based, thus the need for a consensus based on expert opinion.     

Impact of fatty acid status on immune function of children in low-income countries

In vitro and animal studies point to numerous mechanisms by which fatty acids, especially long-chain polyunsaturated fatty acids (LCPUFA), can modulate the innate and adaptive arms of the immune system. These data strongly suggest that improving the fatty acid supply of young children in low-income countries might have immune benefits. Unfortunately, there have been virtually no studies of fatty acid/immune interactions in such settings. Clinical trial registers list over 150 randomized controlled trials (RCTs) involving PUFAs, only one in a low-income setting (the Gambia). We summarize those results here. There was evidence for improved growth and nutritional status, but the primary end point of chronic environmental enteropathy showed no benefit, possibly because the infants were still substantially breastfed. In high-income settings, there have been RCTs with fatty acids (usually LCPUFAs) in relation to 18 disease end points, for some of which there have been numerous trials (asthma, inflammatory bowel disease and rheumatoid arthritis). For these diseases, the evidence is judged reasonable for risk reduction for childhood asthma (but not in adults), as yielding possible benefit in Crohn's disease (insufficient evidence in ulcerative colitis) and for convincing evidence for rheumatoid arthritis at sufficient dose levels, though formal meta-analyses are not yet available. This analysis suggests that fatty acid interventions could yield immune benefits in children in poor settings, especially in non-breastfed children and in relation to inflammatory conditions such as persistent enteropathy. Benefits might include improved responses to enteric vaccines, which frequently perform poorly in low-income settings, and these questions merit randomized trials.     

Limiting authorship in Indian Pediatrics: an initiative to curb gift authorship

Indian Pediatrics limited the number of authorship to 5, 4 and 2 for Brief Reports (BR), Case Reports (CR), and Letters to the Editor (LE), respectively from January 2003, to curb gift authorship. To analyze the impact of this policy, a comparative analysis was conducted for years 2002-2004. Mean (SD) number of authors was comparable for the three categories over 2002-2004 [BR: 4.2(1.7), 3.8(1.4), 3.9(1.5); CR: 3.3(0.8), 3.3(0.8), 3.2(0.8); LE: 2.1(1.3), 1.9(0.9), 1.8(0.5); P > 0.05]. There was a significant reduction in the number of Senior authors during 2003-2004, as compared to 2002 (P > 0.05). The policy resulted in fewer authorship credits for Senior authors.     

The National Movement of Neonatal Resuscitation in India

Summary Birth asphyxia is an important cause of preventable neonatal morbidity and mortality in developing countries. Of the 26 million births each year in India, 4-6 per cent of neonates fail to establish spontaneous breathing at birth. These babies can be helped, if healthcare professionals present at the time of birth are skilled in the art of neonatal resuscitation. Since the introduction of the Neonatal Resuscitation Programme (NRP) by the American Academy of Pediatrics and American Heart Association, organized training programmes for instructors and providers have been launched in India, under the aegis of the National Neonatology Forum (NNF) since 1990. The initial goal was to train the trainers and provide them with the necessary equipment. The NNF created a national faculty of 150 pediatricians and nurses for NRP by conducting certification courses in various regions of the country. The certified faculty members in turn trained 12,000 healthcare professionals in various parts of India over the following 2 years. Simultaneously, in several teaching institutions, NRP was introduced into the curricula of medical and nursing students. This programme provides a uniform, systematic and action-oriented approach to the resuscitation of the newborn. Prospective evaluation of the resuscitation programme in teaching hospitals has revealed the use of rational resuscitation practices and a significant decline in asphyxia-related deaths.     

Conclusiveness of the Cochrane Neonatal Reviews: a systematic analysis

Aim: To assess the conclusiveness of the Cochrane Neonatal Reviews (CNRs). We tested the hypotheses that: 1) the majority of the reviews is inconclusive; 2) the majority of reviews recognizes the need for further studies; 3) the ability to reach a conclusion is dependent upon both the number of studies and the number of patients. We also aimed to determine whether the conclusiveness of the CNRs was affected by time.

Methods: We selected CNRs available in the Cochrane Library in June 2004. The number of randomized clinical trials (RCTs) found, number of RCTs included for analysis, number of patients enrolled, the stated need for further studies, and the conclusiveness of CNRs were recorded.

Results: Out of 170 CNRs, 67.7% were conclusive. The average number of articles was similar, but the total number of patients enrolled was three times higher in the conclusive CNRs. The percentage of articles included in conclusive studies was significantly higher than in inconclusive ones. The vast majority of CNRs recognized the need for further studies. The number of studies included correlated significantly with the total number of patients included. The percentage of conclusive CNRs correlated negatively with year of publication.

Conclusion: The majority of CNRs is conclusive, but emphasizes the need for further studies. The ability of a CNR to reach a conclusion is affected by the cumulative sample size and by the number of studies performed. The probability of a newer review to be conclusive is lower than that of an older review.     

Do we measure the right end points? A systematic review of primary outcomes in recent neonatal randomized clinical trials

OBJECTIVES: We performed a systematic review of primary outcomes in recently published neonatal randomized clinical trials to determine what end points are chosen for the evaluation of therapies in newborn infants. METHODS: MEDLINE was searched in May 1998 for neonatal RCTs that had been published since 1993 in the British Medical Journal, The Journal of Pediatrics, Lancet, The New England Journal of Medicine, and Pediatrics. The primary outcome was identified wherever possible. Continuous measures were distinguished from discrete outcome events. The latter were classified as "long-term" if they were ascertained at least 6 months after birth. The hypothesized relative risk reduction for primary outcome event rates was calculated, where possible. RESULTS: Of 119 eligible reports, 91 had an identifiable primary outcome that was a continuous measure in 46 trials and a discrete event in 45 trials. The median relative risk reduction was 50% for 28 of 40 short-term trials and 40% for 3 of 5 long-term trials. CONCLUSIONS: Most authors of recently published neonatal RCTs in 5 high-profile journals either failed to specify a primary end point or chose a continuous outcome measure. Trials with a discrete primary outcome were often short-term and designed to detect large risk reductions. Therefore modest but important treatment effects were likely missed by many of these trials.     

糖皮质激素预防过敏性紫癜患儿肾损害随机对照试验的Meta分析

目的 评价糖皮质激素对过敏性紫癜（HSP）患儿肾损害的预防作用。方法 检索Cochrane图书馆、Medline、EMBASE、中国期刊全文数据库、万方数据库、中文科技期刊全文数据库等,收集有关糖皮质激素预防HSP患儿肾损害的RCT或类随机对照试验（quasi-RCT）文献,检索文献起止时间均为1990年1月至2012年6月。由2名作者进行资料提取和文献质量评价。应用RevMan 4.3软件进行Meta分析,根据异质性结果选择相应的效应模型分析;无法进行Meta分析时采用描述性分析。结果 5篇RCT和1篇quasi-RCT进入Meta分析。4篇文献描述了具体随机化方法,采用了充分的分配隐藏和盲法,纳入6篇文献均报道了失访和退出情况;4篇为低度偏倚风险,2篇为高度偏倚风险。Meta分析结果显示,诊断HSP后6个月以内肾损害的发生率,糖皮质激素预防组为22.2%(42/189),对照组为26.3%(50/190),合并RR=0.67（95%CI: 0.17～2.62）,差异无统计学意义,P=0.57;诊断HSP后6个月以上肾损害发生率,糖皮质激素预防组为109%(41/373),对照组为12.6%(46/364),合并RR=0.85（95%CI: 0.44～1.64）,差异无统计学意义,P=0.65。剔除2篇高度偏倚风险文献行敏感性分析,结果无改变。结论 本Meta分析结果尚不支持早期糖皮质激素治疗能预防HSP患儿肾脏损害。建议临床医生根据患儿具体临床表现和实验室检查,慎重应用糖皮质激素或辅以抗凝、抗过敏等对症治疗。     

2010年至2014年《中华小儿外科杂志》发表的临床随机对照研究文献分析

目的 分析2010年至2014年《中华小儿外科杂志》发表临床随机对照试验(randomized control trial,RCT)文献情况.方法 人工逐条检索出2010年至2014年《中华小儿外科杂志》所有期刊刊载的临床RCT文献,对每篇文章收稿时间、发表时间、引文总数、中文引文数、英文引文数、文章所属单位、单(或多)中心研究情况、研究阳性结论情况、研究中患儿例数、基金资助情况、参研作者人数和相关RCT研究起止时间、随访时间等指标进行分析.结果 2010年至2014年《中华小儿外科杂志》共刊出临床RCT文章82篇,2012年发表最多,为20篇;2014年最少,为11篇.期均RCT数1.4篇.临床RCT在所有临床研究类文献中占比为11.6％.82篇临床RCT研究的平均发文时滞202 d,其中2010年最短,为160 d(标准差最低,为40),篇均引文数14.3条,篇均研究对象数为116例.临床RCT研究中多中心研究仅3篇,量偏少,所有RCT研究都得出阳性意义的结论,有基金资助的RCT研究17篇,占所有临床RCT总数的20.73％,部分临床RCT文章存在随机分组描述不清,随访时间偏短的问题.发表临床RCT最多的单位是温州医学院附属第二医院和郑州大学第一附属医院,均为9篇.结论 《中华小儿外科杂志》在同类医学期刊中影响较广.该刊RCT研究内容丰富、发文时滞较短,篇均引文数量较多、作者群稳定、级别高.这与其作为国内小儿外科领域最具有影响力和代表我国小儿外科学界最高学术水平杂志的身份相符.     

Sublingual immunotherapy in children with allergic rhinitis: quality of systematic reviews

Systematic reviews have gained popularity as a way to combine the increasing amount of research information. This study assessed the quality of systematic reviews and meta-analyses of sublingual immunotherapy (SLIT) for allergic rhinitis in children, published since 2000. Eligible reviews were identified by searching Medline/Pubmed, Embase, and the Cochrane Library, from 2000 through 2008. Methodological quality was assessed using the assessment of multiple systematic reviews instrument. Ten systematic reviews were included, one of which was published in the Cochrane Library. Eight reviews gave some details about the search strategy. None of the reviews included measures to avoid selection bias. In 60% of the reviews, the methodological quality of the included studies was (partly) assessed. Four reviews pooled the results of individual studies, neglecting clinical heterogeneity. Three of the 10 reviews provided information about sources of funding or grants from industry. Of the 10 reviews, the six reviews with the highest overall score scored 5-8 points, indicating moderate quality. Systematic reviews are useful to evaluate the efficacy of SLIT in children. Although more reviews have become available, the methodological quality could be improved. SLIT for children could be promising, but methodological flaws in the reviews and individual studies are too serious to draw definite conclusions.     

Incidents and errors in neonatal intensive care: a review of the literature

OBJECTIVES: To examine the characteristics of incident reporting systems in neonatal intensive care units (NICUs) in relation to type, aetiology, outcome and preventability of incidents. METHODS: Systematic review. Search strategy: Medline, Embase, Cochrane Library. Included: relevant systematic reviews, randomised controlled trials, observational studies and qualitative research. Excluded: non-systematic reviews, expert opinions, case reports and letters. PARTICIPANTS: hospital units supplying neonatal intensive care. INTERVENTION: none. Outcome: characteristics of incident reporting systems; type, aetiology, outcome and preventability of incidents. RESULTS: No relevant systematic reviews or randomised controlled trials were found. Eight prospective and two retrospective studies were included. Overall, medication incidents were most frequently reported. Available data in the NICU showed that the total error rate was much higher in studies using voluntary reporting than in a study using mandatory reporting. Multi-institutional reporting identified rare but important errors. A substantial number of incidents were potentially harmful. When a system approach was used, many contributing factors were identified. Information about the impact of system changes on patient safety was scarce. CONCLUSIONS: Multi-institutional, voluntary, non-punitive, system based incident reporting is likely to generate valuable information on type, aetiology, outcome and preventability of incidents in the NICU. However, the beneficial effects of incident reporting systems and consecutive system changes on patient safety are difficult to assess from the available evidence and therefore remain to be investigated.