Long term outcomes of simple clinical risk stratification in management of differentiated thyroid cancer.

OBJECTIVE: To establish the long term outcomes of risk stratified management of differentiated thyroid cancer (DTC). BACKGROUND: Guidelines for management of DTC lack a strong evidence base and expose patients to overtreatment. This prospective study of patients diagnosed with DTC between 1977 and 2012 describes the long term outcomes of a conservative risk stratified (AMES) management policy. METHODS: Outcomes were analysed around patient and tumour characteristics, primary intervention (surgery ± radioiodine (RAI)), in terms of mortality, recurrence and reintervention. RESULTS: Median follow-up in 348 patients was 14 years: mean age 48 (range 10-91) years, 257 (73.9%) female, 222 (68.3%) papillary cancer, tumour size 3.4 ± 2.0 cm (mean ± SD). 89 (25.6%) AMES high risk, 116 (33.3%) TNM stage III/IV and 16 (4.6%) had distant metastases. Primary surgery comprised lobectomy in 189 (54.3%): 11 (5.8%) patients had subsequent completion total thyroidectomy with cancer present in five. Primary nodal surgery was performed in 142 (40.8%) patients. 35 (13.5%) low and 43 (48.3%) high risk patients received RAI following initial surgery. Overall disease specific survival (DSS) was 92.1% at 10 years and 90.7% at 20 years. DSS at 20 years was 99.2% in low risk cases. AMES risk scoring predicted both survival and recurrence. Patients receiving RAI and AMES high risk were significantly associated with increased risk of death and recurrence. CONCLUSIONS: Routine total thyroidectomy and RAI are not justifiable for low risk DTC. Treatment should be tailored to risk and AMES risk stratification remains a simple reliable clinical tool.

The accuracy of clinical data: a comparison between central and local data collection.

BACKGROUND: The recent liberalisation of public access to information, including surgical performance, emphasises the necessity for accurate data collection. The Information and Statistics Division of the Scottish Executive (ISD) collect such data for each patient episode, but there is concern about the reliability of this information compared with that collected in local surgical departmental audit. AIM: To determine if diagnostic and operative details were consistent between local audited and national non-audited data sets. METHODS: Three surgical units comprising eight consultants were studied. Epidemiological, diagnostic and operative data for each consultant were accessed from the eScrips Internet resource (ISD Data) and from the departmental database. A unique patient number and date of birth matched individual patient episodes and the correlation between datasets graded for accuracy and consistency. RESULTS: 8375 individual data entries were recorded (ISD 4642, local databases 3733). 3402 pairs, 6408 (76.5%) of the total, matched accurately. 742 (16%) of the ISD entries were duplicates, and in 21% of unpaired entries the wrong consultant was recorded. Overall a clinically acceptable match occurred in 86.9% of paired entries for diagnosis and 84.0% for operation. The highest match with ISD data for diagnosis (88.8%) and operation (91.8%) occurred in the unit which holds a weekly audit meeting to validate information. DISCUSSION: There are significant discrepancies in surgical data between the local audit databases and central data. There is significant duplication of entries and inaccurate consultant allocation in ISD data. The promulgation of inaccurate information could threaten reputation or career and clinicians should play a more active role in ensuring clinical data are correct.

The measurement and monitoring of surgical adverse events.

BACKGROUND: Surgical adverse events contribute significantly to postoperative morbidity, yet the measurement and monitoring of events is often imprecise and of uncertain validity. Given the trend of decreasing length of hospital stay and the increase in use of innovative surgical techniques--particularly minimally invasive and endoscopic procedures--accurate measurement and monitoring of adverse events is crucial. OBJECTIVES: The aim of this methodological review was to identify a selection of common and potentially avoidable surgical adverse events and to assess whether they could be reliably and validly measured, to review methods for monitoring their occurrence and to identify examples of effective monitoring systems for selected events. This review is a comprehensive attempt to examine the quality of the definition, measurement, reporting and monitoring of selected events that are known to cause significant postoperative morbidity and mortality. METHODS - SELECTION OF SURGICAL ADVERSE EVENTS: Four adverse events were selected on the basis of their frequency of occurrence and likelihood of evidence of measurement and monitoring: (1) surgical wound infection; (2) anastomotic leak; (3) deep vein thrombosis (DVT); (4) surgical mortality. Surgical wound infection and DVT are common events that cause significant postoperative morbidity. Anastomotic leak is a less common event, but risk of fatality is associated with delay in recognition, detection and investigation. Surgical mortality was selected because of the effort known to have been invested in developing systems for monitoring surgical death, both in the UK and internationally. Systems for monitoring surgical wound infection were also included in the review. METHODS - LITERATURE SEARCH: Thirty separate, systematic literature searches of core health and biomedical bibliographic databases (MEDLINE, EMBASE, CINAHL, HealthSTAR and the Cochrane Library) were conducted. The reference lists of retrieved articles were reviewed to locate additional articles. A matrix was developed whereby different literature and study designs were reviewed for each of the surgical adverse events. Each article eligible for inclusion was independently reviewed by two assessors. METHODS - CRITICAL APPRAISAL: Studies were appraised according to predetermined assessment criteria. Definitions and grading scales were assessed for: content, criterion and construct validity; repeatability; reproducibility; and practicality (surgical wound infection and anastomotic leak). Monitoring systems for surgical wound infection and surgical mortality were assessed on the following criteria: (1) coverage of the system; (2) whether or not denominator data were collected; (3) whether standard and agreed definitions were used; (4) inclusion of risk adjustment; (5) issues related to data collection; (6) postdischarge surveillance; (7) output in terms of feedback and wider dissemination. RESULTS - SURGICAL WOUND INFECTION: A total of 41 different definitions and 13 grading scales of surgical wound infection were identified from 82 studies. Definitions of surgical wound infection varied from presence of pus to complex definitions such as those proposed by the Centres for Disease Control in the USA. A small body of literature has been published on the content, criterion and construct validity of different definitions, and comparisons have been made against wound assessment scales and multidimensional indices. There are examples of comprehensive hospital-based monitoring systems of surgical wound infection, mainly under the auspices of nosocomial surveillance. To date, however, there is little evidence of systematic measurement and monitoring of surgical wound infection after hospital discharge. RESULTS - ANASTOMOTIC LEAK: Over 40 definitions of anastomotic leak were extracted from 107 studies of upper gastrointestinal, hepatopancreaticobiliary and lower gastrointestinal surgery. No formal evaluations were found that assessed the validity or reliability of definitions or severity scales of anastomotic leak. One definition was proposed during a national consensus workshop, but no evidence of its use was found in the surgical literature. The lack of a single definition or gold standard hampers comparison of postoperative anastomotic leak rates between studies and institutions. RESULTS - DEEP VEIN THROMBOSIS: Although a critical review of the DVT literature could not be completed within the realms of this review, it was evident that a number of new techniques for the detection and diagnosis of DVT have emerged in the last 20 years. The group recommends a separate review be undertaken of the different diagnostic tests to detect DVT. RESULTS - SURGICAL MORTALITY MONITORING SYSTEMS: The definition of surgical mortality is relatively consistent between monitoring systems, but duration of follow-up of death postdischarge varies considerably. The majority of systems report in-hospital mortality rates; only some have the potential to link deaths to national death registers. Risk assessment is an important factor and there should be a distinction between recording pre-intervention factors and postoperative complications. A variety of risk scoring systems was identified in the review. Factors associated with accurate and complete data collection include the employment of local, dedicated personnel, simple and structured prompts to ensure that clinical input is complete, and accurate and automated data capture and transfer. CONCLUSIONS: The use of standardised, valid and reliable definitions is fundamental to the accurate measurement and monitoring of surgical adverse events. This review found inconsistency in the quality of reporting of postoperative adverse events, limiting accurate comparison of rates over time and between institutions. The duration of follow-up for individual events will vary according to their natural history and epidemiology. Although risk-adjusted aggregated rates can act as screening or warning systems for adverse events, attribution of whether events are avoidable or preventable will invariably require further investigation at the level of the individual, unit or department. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: (1) A single, standard definition of surgical wound infection is needed so that comparisons over time and between departments and institutions are valid, accurate and useful. Surgeons and other healthcare professionals should consider adopting the 1992 Centers for Disease Control (CDC) definition for superficial incisional, deep incisional and organ/space surgical site infection for hospital monitoring programmes and surgical audits. There is a need for further methodological research into the performance of the CDC definition in the UK setting. (2) There is a need to formally assess the reliability of self-diagnosis of surgical wound infection by patients. (3) There is a need to assess formally the reliability of case ascertainment by infection control staff. (4) Work is needed to create and agree a standard, valid and reliable definition of anastomotic leak which is acceptable to surgeons. (5) A systematic review is needed of the different diagnostic tests for the diagnosis of DVT. (6) The following variables should be considered in any future DVT review: anatomical region (lower limb, upper limb, pelvis); patient presentation (symptomatic, asymptomatic); outcome of diagnostic test (successfully completed, inconclusive, technically inadequate, negative); length of follow-up; cost of test; whether or not serial screening was conducted; and recording of laboratory cut-off values for fibrinogen equivalent units. (7) A critical review is needed of the surgical risk scoring used in monitoring systems. (8) In the absence of automated linkage there is a need to explore the benefits and costs of monitoring in primary care. (9) The growing potential for automated linkage of data from different sources (including primary care, the private sector and death registers) needs to be explored as a means of improving the ascertainment of surgical complications, including death. This linkage needs to be within the terms of data protection, privacy and human rights legislation. (10) A review is needed of the extent of the use and efficiency of routine hospital data versus special collections or voluntary reporting.

The quality of measurement of surgical wound infection as the basis for monitoring: a systematic review.

Comparison of postoperative surgical wound infection rates between institutions and over time is only valid if standard, valid and reliable definitions are used. The aim of this review was to assess evidence of validity and reliability of the definition and measurement of surgical wound infection. A systematic review was undertaken of prospective studies of surgical wound infection published over a seven-year period; 1993-1999. The information extracted from individual studies included: definition of surgical wound infection; details of wound assessment scale, scoring or grading scale systems; and evidence of assessment of validity, reliability and feasibility of identified definitions and grading systems. Two independent reviewers appraised 112 prospective studies, 90 of which were eligible for inclusion; eight studies assessed validity and/or reliability. Forty-one different definitions of surgical wound infection were identified, five of which were 'standard' definitions proposed by multi-disciplinary groups. Presence of pus was the most frequently used single component of any definition; the CDC definitions of 1988 and 1992 were the most widely implemented standard definitions; and the ASEPSIS wound assessment scale was the most frequently used quantitative grading tool. Only two formal validations of a definition were found, and six studies of reliability. This review highlights the extent of variation in definition of surgical wound infection used in clinical practice, and the need for validation of both content and organization of a surveillance system. However, realistically, there will have to be a balance between the quality of the measurement and the practicality of surveillance.

Revisional surgery after failed laparoscopic anterior fundoplication.

BACKGROUND: Partial fundoplication may have functional advantages over a circumferential wrap but the reconstruction is more complex. Revisional surgery for recurrent reflux may be more difficult because of the additional suturing involved in the original operation. We report experience with revisional surgery in a large cohort of patients who had undergone laparoscopic anterior fundoplication and hiatal repair. METHODS: Between August 1993 and September 1999, 11 (3.5%) of 309 patients who had laparoscopic anterior fundoplication for uncomplicated gastroesophageal reflux disease required revisional surgery (1 open and 10 laparoscopic revisions). Data were retrieved from a prospective database supplemented by a postal questionnaire following the second operation. RESULTS: The operative findings were posterior hiatal disruption (n = 9), anterior paraesophageal hernia (n = 1), and inadequate initial esophageal mobilization (n = 1). There were no conversions to open surgery in the laparoscopic group. Ten (91%) of the respondents described the outcome of their repeat procedure as either good or excellent. All patients would recommend the repeat procedure to patients with similar symptoms. CONCLUSIONS: Revisional surgery after laparoscopic anterior fundoplication can be performed safely with a good outcome. Modifications to technique both in the primary procedure and for revision may decrease the incidence of early technical failure.

The role of intravenous cholangiography in pre-operative assessment for laparoscopic cholecystectomy.

With the advent of laparoscopic cholecystectomy, pre-operative identification of calculi in the common bile duct has become increasingly important. In patients without clinical or biochemical evidence of common bile duct calculi, debate continues as to the value of intravenous cholangiography (IVC) as a screening modality for the detection of unsuspected choledocholithiasis. In a prospective series of 180 patients, IVC was used to assess the common bile duct in 113 patients at low risk of choledocholithiasis, 51 patients at high risk underwent endoscopic retrograde cholangiography (ERC) and sphincterotomy if indicated, and in 16 patients, for a variety of reasons, no pre-operative cholangiography was performed. 31% of those who had ERC and two (1.8%) of those who had IVC had duct calculi. These data do not support the routine use of IVC in patients with no evidence of common bile duct calculi and its routine use has been discontinued.

The long term behaviour of autogeneou vein by-pass grafts.

The results of the follow-up of 50 consecutive atuogeneous vein bypass grafts during 1958-65 are described. Arteriography was performed at regular intervals throughout the follow-up lasting from 8-15 years. 11 grafts failed in less than 2 years and were considered technical failures. Thereafter, of the 37 cases on whom arteriographic information is available, a further 5 grafts failed. Deterioration of the graft itself occurred in 19 percent, proximal anastomosis dilatation it 16 percent, and distal anastomosis narrowing in 25 percent. Improvement of flow to the lower leg vessels did not accelerate progression of the long saphenous vein at the time of operation is the limiting factor in longterm graft deterioration. The majority of grafts remained patient without degeneration for up to 15 years.

Towards measurement of outcome for patients with varicose veins.

OBJECTIVE: To develop a valid and reliable outcome measure for patients with varicose veins. DESIGN: Postal questionnaire survey of patients with varicose veins. SETTING: Surgical outpatient departments and training general practices in Grampian region. SUBJECTS: 373 patients, 287 of whom had just been referred to hospital for their varicose veins and 86 who had just consulted a general practitioner for this condition and, for comparison, a random sample of 900 members of the general population. MAIN MEASURES: Content validity, internal consistency, and criterion validity. RESULTS: 281(76%) patients (mean age 45.8; 76% female) and 542(60%) of the general population (mean age 47.9; 54% female) responded. The questionnaire had good internal consistency as measured by item-total correlations. Factor analysis identified four important health factors: pain and dysfunction, cosmetic appearance, extent of varicosity and complications. The validity of the questionnaire was demonstrated by a high correlation with the SF-36 health profile, which is a general measure of patients' health. The perceived health of patients with varicose veins, as measured by the SF-36, was significantly lower than that of the sample of the general population adjusted for age and a lower proportion of women. CONCLUSION: A clinically derived questionnaire can provide a valid and reliable tool to assess the perceived health of patients with varicose veins. IMPLICATIONS: The questionnaire may be used to justify surgical treatment of varicose veins.

Risk of neoplasia and malignancy in "dominant" thyroid swellings.

OBJECTIVE: To determine the risk of neoplasia and malignancy in "dominant" thyroid swellings. DESIGN: Prospective analysis during six years. SETTING: Thyroid clinic serving the Grampian region. PATIENTS: 574 consecutive patients presenting with a discrete thyroid swelling, of whom 179 (31%) were classified clinically as having a dominant area of enlargement within a multinodular gland. RESULTS: After clinical and cytological assessment 77 dominant swellings were excised. Of the excised swellings, 45 were non-neoplastic and 32 neoplastic, including 11 malignant lesions. The minimum incidence of neoplasia and malignancy in all 179 dominant swellings was therefore 18% and 6% respectively. CONCLUSION: Dominant thyroid swellings should be regarded with greater clinical suspicion than has been traditional.

Management of isolated thyroid swellings: a prospective six year study of fine needle aspiration cytology in diagnosis.

OBJECTIVE: To audit the accuracy and impact on the frequency of operation of fine needle aspiration cytology of isolated thyroid swellings. DESIGN: Prospective analysis over six years of cytological predictions compared with histological findings. SETTING: Thyroid clinic serving the Grampian region. PATIENTS: 395 Consecutive patients presenting with an isolated thyroid swelling, 307 of whom underwent surgical excision. Analysis was confined to a subgroup of 283 patients with satisfactory aspirates who were operated on. RESULTS: The positive predictive value of aspiration cytology for detecting malignant disease was 100% and the sensitivity 83%. The sensitivity for the detection of neoplasia (frank malignancy together with follicular adenomas) was 76%. The specificity was 58% and the overall accuracy 69%. Recalculation of data in previous papers with strict criteria showed the accuracy of aspiration cytology to be variable and lower than is widely accepted. Since the introduction of aspiration cytology 21% fewer operations for isolated thyroid swellings have been performed. CONCLUSIONS: As a basis of selection for surgical excision of isolated thyroid swellings according to prediction of neoplasia fine needle aspiration cytology is less reliable than is widely accepted. It is an adjunct to management rather than a definitive test, and negative cytological results do not exclude neoplastic disease. Further study should take account of the implications of repeated clinic attendances for review and aspiration as these may culminate in delayed surgical treatment.

A cross-specialty survey to assess the application of risk stratified surgery for differentiated thyroid cancer in the UK.

INTRODUCTION: This study describes variability of treatment for differentiated thyroid cancer among thyroid surgeons, in the context of changing patterns of thyroid surgery in the UK. METHODS: Hospital Episodes Statistics on thyroid operations between 1997 and 2012 were obtained for England. A survey comprising six scenarios of varying 'risk' was developed. Patient/tumour information was provided, with five risk stratified or non-risk stratified treatment options. The survey was distributed to UK surgical associations. Respondent demographics were categorised and responses analysed by assigned risk stratified preference. RESULTS: From 1997 to 2012, the Hospital Episode Statistics data indicated there was a 55% increase in the annual number of thyroidectomies with a fivefold increase in otolaryngology procedures and a tripling of cancer operations. Of the surgical association members surveyed, 264 respondents reported a thyroid surgery practice. Management varied across and within the six scenarios, and was not related consistently to the level of risk. Associations were demonstrated between overall risk stratified preference and higher volume practice (>25 thyroidectomies per year) (p=0.011), fewer years of consultant practice (p=0.017) and multidisciplinary team participation (p=0.037). Logistic regression revealed fewer years of consultant practice (odds ratio [OR]: 0.96/year in practice, 95% confidence interval [CI]: 0.922-0.997, p=0.036) and caseload of >25/year (OR 1.92, 95% CI: 1.044-3.522, p=0.036) as independent predictors of risk stratified preference. CONCLUSIONS: There is a substantial contribution to thyroid surgery in the UK by otolaryngology surgeons. Adjusting management according to established case-based risk stratification is not widely applied. Higher caseload was associated with a preference for management tailored to individual risk.

Minimal access surgery compared with medical management for gastro-oesophageal reflux disease: five year follow-up of a randomised controlled trial (REFLUX).

OBJECTIVES: To determine the long term clinical effectiveness of laparoscopic fundoplication as an alternative to drug treatment for chronic gastro-oesophageal reflux disease (GORD). DESIGN: Five year follow-up of multicentre, pragmatic randomised trial (with parallel non-randomised preference groups). SETTING: Initial recruitment in 21 UK hospitals. PARTICIPANTS: Responders to annual questionnaires among 810 original participants. At entry, all had had GORD for >12 months. INTERVENTION: The surgeon chose the type of fundoplication. Medical therapy was reviewed and optimised by a specialist. Subsequent management was at the discretion of the clinician responsible for care, usually in primary care. MAIN OUTCOME MEASURES: Primary outcome measure was self reported quality of life score on disease-specific REFLUX questionnaire. Other measures were health status (with SF-36 and EuroQol EQ-5D questionnaires), use of antireflux medication, and complications. RESULTS: By five years, 63% (112/178) of patients randomised to surgery and 13% (24/179) of those randomised to medical management had received a fundoplication (plus 85% (222/261) and 3% (6/192) of those who expressed a preference for surgery and for medical management). Among responders at 5 years, 44% (56/127) of those randomised to surgery were taking antireflux medication versus 82% (98/119) of those randomised to medical management. Differences in the REFLUX score significantly favoured the randomised surgery group (mean difference 8.5 (95% CI 3.9 to 13.1), P<0.001, at five years). SF-36 and EQ-5D scores also favoured surgery, but were not statistically significant at five years. After fundoplication, 3% (12/364) had surgical treatment for a complication and 4% (16) had subsequent reflux-related operations-most often revision of the wrap. Long term rates of dysphagia, flatulence, and inability to vomit were similar in the two randomised groups. CONCLUSIONS: After five years, laparoscopic fundoplication continued to provide better relief of GORD symptoms than medical management. Adverse effects of surgery were uncommon and generally observed soon after surgery. A small proportion had re-operations. There was no evidence of long term adverse symptoms caused by surgery. TRIAL REGISTRATION: Current Controlled Trials ISRCTN15517081.

Clinical and economic evaluation of laparoscopic surgery compared with medical management for gastro-oesophageal reflux disease: 5-year follow-up of multicentre randomised trial (the REFLUX trial).

BACKGROUND: Despite promising evidence that laparoscopic fundoplication provides better short-term relief of gastro-oesophageal reflux disease (GORD) than continued medical management, uncertainty remains about whether benefits are sustained and outweigh risks. OBJECTIVE: To evaluate the long-term clinical effectiveness, cost-effectiveness and safety of laparoscopic surgery among people with GORD requiring long-term medication and suitable for both surgical and medical management. DESIGN: Five-year follow-up of a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. Cost-effectiveness was assessed alongside the trial using a NHS perspective for costs and expressing health outcomes in terms of quality-adjusted life-years (QALYs). SETTING: Follow-up was by annual postal questionnaire and selective hospital case notes review; initial recruitment in 21 UK hospitals. PARTICIPANTS: Questionnaire responders among the 810 original participants. At entry, all had documented evidence of GORD and symptoms for > 12 months. Questionnaire response rates (years 1-5) were from 89.5% to 68.9%. INTERVENTIONS: Three hundred and fifty-seven participants were recruited to the randomised comparison (178 randomised to surgical management and 179 randomised to continued medical management) and 453 to the preference groups (261 surgical management and 192 medical management). The surgeon chose the type of fundoplication. MAIN OUTCOME MEASURES: Primary: disease-specific outcome measure (the REFLUX questionnaire); secondary: Short Form questionnaire-36 items (SF-36), European Quality of Life-5 Dimensions (EQ-5D), NHS resource use, reflux medication, complications. RESULTS: The randomised groups were well balanced. By 5 years, 63% in the randomised surgical group and 13% in the randomised medical management group had received a total or partial wrap fundoplication (85% and 3% in the preference groups), with few perioperative complications and no associated deaths. At 1 year (and 5 years) after surgery, 36% (41%) in the randomised surgical group - 15% (26%) of those who had surgery - were taking proton pump inhibitor medication compared with 87% (82%) in the randomised medical group. At each year, differences in the REFLUX score significantly favoured the randomised surgical group (a third of a SD; p< 0.01 at 5 years). SF-36 and EQ-5D scores also favoured surgery, but differences attenuated over time and were generally not statistically significant at 5 years. The worse the symptoms at trial entry, the larger the benefit observed after surgery. Those randomised to medical management who subsequently had surgery had low baseline scores that markedly improved after surgery. Following fundoplication, 3% had surgical treatment for a complication and 4% had subsequent reflux-related operations - most often revision of the wrap. Dysphagia, flatulence and inability to vomit were similar in the two randomised groups. The economic analysis indicated that surgery was the more cost-effective option for this patient group. The incremental cost-effectiveness ratio for surgery in the base case was £7028 per additional QALY; these findings were robust to changes in approaches and assumptions. The probability of surgery being cost-effective at a threshold of £20,000 per additional QALY was > 0.80 for all analyses. CONCLUSIONS: After 5 years, laparoscopic fundoplication continues to provide better relief of GORD symptoms with associated improved health-related quality of life. Complications of surgery were uncommon. Despite being initially more costly, a surgical policy is highly likely to be cost-effective. TRIAL REGISTRATION: Current Controlled Trials ISRCTN15517081. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 22. See the HTA programme website for further project information.

Identification of risk factors by systematic review and development of risk-adjusted models for surgical site infection.

BACKGROUND: Surgical site infections (SSIs) are complications of surgery that cause significant postoperative morbidity. SSI has been proposed as a potential indicator of the quality of care in the context of clinical governance and monitoring of the performance of NHS organisations against targets. OBJECTIVES: We aimed to address a number of objectives. Firstly, identify risk factors for SSI, criteria for stratifying surgical procedures and evidence about the importance of postdischarge surveillance (PDS). Secondly, test the importance of risk factors for SSI in surveillance databases and investigate interactions between risk factors. Thirdly, investigate and validate different definitions of SSI. Lastly, develop models for making risk-adjusted comparisons between hospitals. DATA SOURCES: A single hospital surveillance database was used to address objectives 2 and 3 and the UK Surgical Site Infection Surveillance Service database to address objective 4. STUDY DESIGN: There were four elements to the research: (1) systematic reviews of risk factors for SSI (two reviewers assessed titles and abstracts of studies identified by the search strategy and the quality of studies was assessed using the Newcastle Ottawa Scale); (2) assessment of agreement between four SSI definitions; (3) validation of definitions of SSI, quantifying their ability to predict clinical outcomes; and (4) development of operation-specific risk models for SSI, with hospitals fitted as random effects. RESULTS: Reviews of SSI risk factors other than established SSI risk indices identified other risk; some were operation specific, but others applied to multiple operations. The factor most commonly identified was duration of preoperative hospital stay. The review of PDS for SSI confirmed the need for PDS if SSIs are to be compared meaningfully over time within an institution. There was wide variation in SSI rate (SSI%) using different definitions. Over twice as many wounds were classified as infected by one definition only as were classified as infected by both. Different SSI definitions also classified different wounds as being infected. The two most established SSI definitions had broadly similar ability to predict the chosen clinical outcomes. This finding is paradoxical given the poor agreement between definitions. Elements of each definition not common to both may be important in predicting clinical outcomes or outcomes may depend on only a subset of elements which are common to both. Risk factors fitted in multivariable models and their effects, including age and gender, varied by surgical procedure. Operative duration was an important risk factor for all operations, except for hip replacement. Wound class was included least often because some wound classes were not applicable to all operations or were combined because of small numbers. The American Association of Anesthesiologists class was a consistent risk factor for most operations. CONCLUSIONS: The research literature does not allow surgery-specific or generic risk factors to be defined. SSI definitions varied between surveillance programmes and potentially between hospitals. Different definitions do not have good agreement, but the definitions have similar ability to predict outcomes influenced by SSI. Associations between components of the National Nosocomial Infections Surveillance risk index and odds of SSI varied for different surgical procedures. There was no evidence for effect modification by hospital. Estimates of SSI% should be disseminated within institutions to inform infection control. Estimates of SSI% across institutions or countries should be interpreted cautiously and should not be assumed to reflect quality of medical care. Future research should focus on developing an SSI definition that has satisfactory psychometric properties, that can be applied in everyday clinical settings, includes PDS and is formulated to detect SSIs that are important to patients or health services. FUNDING: The National Institute for Health Research Technology Assessment programme.

Outcome of a conservative policy for managing acute sigmoid diverticulitis.

BACKGROUND: A conservative policy for patients presenting with acute sigmoid diverticulitis is associated with a low operation rate, and low overall and operative mortality rates. The long-term consequences of such a policy were investigated. METHODS: Data were collected prospectively for 232 patients with acute sigmoid diverticulitis between 1990 and 2004. Details of all subsequent readmissions were obtained and survival to August 2005 was analysed. RESULTS: Of the 232 patients admitted, 60 (25.9 per cent) were known to have diverticulosis; in 172 patients it was a new diagnosis. Thirty-eight patients (16.4 per cent) underwent sigmoid resection, with one death. Three elderly patients in whom a decision was made not to operate had perforated diverticulitis at autopsy. Of 191 patients discharged without resection, 35 (18.3 per cent) subsequently underwent sigmoid resection: 26 (13.6 per cent) elective and nine (4.7 per cent) emergency, with one death. CONCLUSION: A conservative policy is safe in both the short term and the long term.

Ten-year computerized audit of infection after abdominal surgery.

A prospective audit of the frequency of infective complications after all abdominal operations was carried out between January 1977 and December 1986. A total of 3100 abdominal procedures (2041 elective; 1059 emergency) were performed in 3056 patients. There were 50 (1.6 per cent) in-hospital and 66 (2.1 per cent) late wound infections (overall 3.7 per cent). Fifty-four (1.8 per cent) patients developed postoperative intraperitoneal sepsis. Ninety-eight patients died (overall mortality 3.2 per cent) and intraperitoneal sepsis was a related factor in twelve (0.4 per cent). Wound infection, peritoneal sepsis and mortality were related to the degree of operative contamination and to reoperation. The results support the traditional, although sometimes inadequately stressed, teaching that technique is an important factor in preventing infection. Infection is also reduced by peroperative antibiotic lavage. The limited value and the potential difficulties of the unstructured introduction of computerized audit should be recognized.

Emergency surgery for diverticular disease complicated by generalized and faecal peritonitis: a review.

There is little uniformity in either the indications for operation, the classification of the pathology or the operative management of generalized or faecal peritonitis secondary to perforated diverticular disease. Nevertheless, this review has shown a clear advantage both in terms of immediate mortality and morbidity for primary resection over conservative operations in which the colon is retained in the abdomen. We propose that, when a clinical diagnosis of localized sepsis secondary to diverticular disease is made, the management should be nonoperative with systemic antibiotics and supportive therapy. Operation should be reserved for those patients with obvious generalized peritonitis or failure of conservative treatment. When operation is necessary the affected sigmoid loop should be resected and the operation completed as a Hartmann's procedure in all but the most favourable circumstances when a primary anastomosis may be considered after on-table irrigation of the colon.

Outcome of surgery for Graves' disease re-examined.

The outcome of surgery for Graves' disease in terms of early and late morbidity was studied in 161 patients undergoing subtotal thyroidectomy in the 10-year period 1976-1985. Eighty of these patients had a minimum follow-up of 5 years. There was a low operative morbidity and a zero mortality. The weight of thyroid tissue preserved (in the range 5-10 g) influenced the prevalence of hypothyroidism at one year and at five years. There was a cumulative incidence of hypothyroidism which could not be reliably predicted from biochemical results during the first year. Over 60 per cent of patients with subclinical hypothyroidism at 4 months (63 per cent) or 1 year (70 per cent) did not subsequently need thyroxine replacement within 5 years. Patients remained at risk of developing recurrent toxicity indefinitely and the risk was significantly greater in patients with small goitres (less than 50 g). Our results may be improved by leaving larger remnants (9-10 g) in most patients and smaller remnants (2-4 g) in those with small glands in whom alternative treatment, which is to be preferred, is not acceptable. After subtotal thyroidectomy for Graves' disease lifelong follow-up is necessary.