Prospective study of enhanced recovery after surgery protocol in children undergoing reconstructive operations.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocol is a set of peri-operative strategies to increase speed of recovery. ERAS is well established in adults but has not been well studied in children. OBJECTIVE: The purpose of the current study was to establish the safety and efficacy of an ERAS protocol in pediatric urology patients undergoing reconstructive operations. It was hypothesized that ERAS would reduce length of stay and decrease complications when compared with historical controls. STUDY DESIGN: Institutional Review Board approval was obtained to prospectively enroll patients aged <18 years if they had undergone urologic reconstruction that included a bowel anastomosis. ERAS included: no bowel preparation, administration of pre-operative oral carbohydrate liquid, avoidance of opioids, regional anesthesia, laparoscopy when feasible, no postoperative nasogastric tube, early feeding, and early removal of intravenous fluids (IVF). Recent (2009-2014) historical controls were propensity matched in a 2:1 ratio on age, sex, ventriculoperitoneal shunt status and whether the patient was undergoing bladder augmentation. Outcomes were protocol adherence, length of stay (LOS), emergency department (ED) visits, re-admission within 30 days, re-operations and adverse events occurring within 90 days of surgery. RESULTS: A total of 26 historical and 13 ERAS patients were included. Median ages were 10.4 (IQR 8.0-12.4) and 9.9 years (IQR 9.1-11), respectively (P = 0.94) (see Summary Table). There were no significant between-group differences in prior abdominal surgery (38% vs 62%), rate of augmentation (88% vs 92%) or primary diagnosis of spina bifida (both 62%). ERAS significantly improved use of pre-operative liquid load (P < 0.001), avoidance of opioids (P = 0.046), early discontinuation of IVF (P < 0.001), and early feeding (P < 0.001). Protocol adherence improved from 8/16 (IQR 4-9) historically to 12/16 (IQR 11-12) after implementation of ERAS. LOS decreased from 8 days to 5.7 days (P = 0.520). Complications of any grade per patient decreased from 2.1 to 1.3 (OR 0.71, 95% CI 0.51-0.97). There were fewer complications per patient across all grades with ERAS. No differences were seen in emergency department (ED) visits, re-admissions and re-operations. DISCUSSION: Implementation improved consistency of care delivered. Tenets of ERAS that appeared to drive improvements included maintenance of euvolemia through avoidance of excess fluids, multimodal analgesia, and early feeding. CONCLUSION: ERAS decreased length of stay and 90-day complications after pediatric reconstructive surgery without increased re-admissions, re-operations or ED visits. A multicenter study will be required to confirm the potential benefits of adopting ERAS.

Inter-rater reliability of the APD, SFU and UTD grading systems in fetal sonography and MRI.

INTRODUCTION: Antenatal hydronephrosis (ANH) is frequently detected on screening obstetric ultrasonography. Common ANH grading systems include the anterior-posterior diameter (APD) and the Society for Fetal Urology (SFU) grading system. Recent developments in the management of ANH include the use of fetal magnetic resonance imaging (MRI), and a new grading system - Urinary Tract Dilation (UTD). This study reviewed patients who underwent fetal MRI and ultrasound, and compared the grading systems across these imaging modalities. MATERIALS AND METHODS: Patients who underwent paired fetal MRI and ultrasound studies between January 2012 and January 2014 were included. Two pediatric urologists and a pediatric radiologist reviewed the studies. Data collected included APD, SFU grade, and UTD grade. Fleiss' kappa statistic determined the inter-rater reliability (IRR) of the SFU and UTD grading within each imaging modality. Intra-class correlation assessed the consistency of the APD measurements. RESULTS: Forty-seven patients and 88 renal units were evaluated. Median gestational age was 22 weeks. Kappa values of the SFU grading system indicated fair IRR for ultrasound imaging and moderate IRR for MRI imaging, while the UTD grading system reached moderate IRR for both. The IRR of the SFU grading system was improved with the use of MRI, while the UTD grading system was no different. The APD intraclass correlation coefficient improved significantly when measured by MRI. As the ultrasound SFU grade increased, the odds of the MRI SFU grade being scored higher increased by a factor of 3.7. There was no difference between ultrasound and MRI when using the UTD grading system. DISCUSSION: This study was the first to assess the UTD system in a cohort of patients who underwent paired ultrasound and MRI studies. The results suggested that the UTD system might improve IRR, compared with the SFU system. The use of fetal MRI may improve the IRR of the SFU grading system. It also found that the proportion of SFU grades was affected by the imaging modality, raising the possibility that MRI 'overcalls' the SFU grade, compared with ultrasound. This difference was not observed using the UTD grading system. The most important limitation was the selection bias favoring complex pathology with severe ANH diagnosed at an early gestational age. CONCLUSIONS: In this unique cohort, the UTD system improved IRR when compared to the SFU grading system. Fetal MRI improved the IRR of the SFU grading system, and improved the APD intraclass correlation. The SFU grading was likely to be higher when assessed by MRI vs ultrasound, but the UTD grade was not affected by the imaging modality.

Continuous local anesthetic infusion for children with spina bifida undergoing major reconstruction of the lower urinary tract.

OBJECTIVE: While many options for postoperative analgesia are available to the general patient population, choices are limited for individuals with spinal dysraphism. We hypothesized that the use of continuous local anesthetic infusion following major reconstruction of the lower urinary tract in children with spina bifida would significantly decrease need for opiate use, while maintaining adequate pain control. MATERIALS AND METHODS: Children with spina bifida who underwent major reconstruction of the lower urinary tract at Children's Hospital Colorado were identified from January, 2003 through January, 2013 were identified. In addition to enterocycstoplasty, procedures included Mitrofanoff or Monti creation, bladder neck reconstruction, and Malone antegrade continence enema. Patients who had local anesthetic infusion catheters placed in the incision were compared to patients without catheters. Opioid consumption was calculated by conversion of any opiates into IV morphine (mg/kg) on postoperative days (POD) 0-3. Pain was assessed by mean and maximum FLACC scores on POD 0-2. Use of antiemetic medications and wound related complications were recorded as secondary metrics. Patients with other etiologies for neurogenic bladder and bowel were excluded. Patients whose pain was assessed by other assessment scales were excluded. Chi-squared analysis was used for nominal variables, students t-test was used for analysis of continuous variables. P values <0.05 were considered significant. RESULTS: 36 myelomeningocele patients who underwent primary enterocystoplasty met the inclusion criteria. All surgeries were open procedures. 24 patients in the infusion catheter group were compared to 12 patients who received primary analgesia by PCA or IV narcotics. There were no significant differences in age, sex, weight or spinal defect level between the two groups. Opioid use, as defined by IV morphine equivalents, was significantly less in the wound soaker group on all PODs. The total opioid use after POD #0-3 was 0.55 mg/kg in the wound soaker group vs 1.66 mg/kg in the IV/PCA group (p = 0.03). FLACC scores were uniformly lower in the wound soaker group, but were not significantly different. There was a significant decrease in need for postoperative antiemetic use in the wound soaker group (36.5% vs 83.3%, p = 0.014). Complications and hospital stay were similar between both groups. DISCUSSION: The advantage of local anesthesia is the reduction of systemic opioids and their subsequent adverse side effects. Our results suggest that in children with spina bifida undergoing major reconstruction of the lower urinary tract narcotic consumption is approximately 1/3 when continuous local anesthetic catheters are placed into the incision. The need for antiemetic medication is also significantly less. While this technique has been validated in a variety of other settings, it may be most beneficial in patients with myelomeningocele or other spinal dysraphism where epidural placement is generally contraindicated and narcotic use may have a particularly deleterious effect on preexisting neurogenic bowel function. The primary limitation of our study is that it is a retrospective review of a limited number of patients. Patients were not randomized and subject to other management differences that could have influenced our results in unknown ways. CONCLUSIONS: Continuous local anesthetic catheters are a simple, effective alternative strategy to provide postoperative analgesia while reducing systemic opiate use and associated adverse effects.

How do I do it: Continuous local anesthetic infusion for children with spinal dysraphism undergoing major reconstruction of the lower urinary tract.

Postoperative pain control is a fundamental aspect of contemporary pediatric surgery. While many options for analgesia are available to the general patient population, choices are limited for individuals with spinal dysraphism who undergo major urologic procedures. Continuous infusion of local anesthetics has been shown to improve postoperative pain scores and decreases the need for systemic analgesia. We present our technique for continuous local anesthetic infusion utilizing readily available equipment with limited additional cost.

Injury to recreational and professional cricket players: circumstances, type and potential for intervention.

This paper describes injury (circumstances and type) experienced by sub-populations at all levels of cricket and, where possible, the type of protective equipment used. The sample differs to that generally examined in the literature in that it is not restricted to evaluation of elite and professional players only. Over a 6-year period (2000-2005), 498 cases were identified. The average age of injury was 27 years and 86% of those injured were male. The population incidence rate was 2.3 per 100,000 per year, and participation incidence rate 39 per 100,000 per year. Over all age groups upper limb (36%) and lower limb (31%) were most commonly injured. Fracture was the main type of injury. Differences among age groups were identified. Children (<10 years) most commonly suffered head injury (contact with the bat); 10-19 year olds, head, upper and lower limb injury (in similar proportions) generally from contact with bat/ball; those over 20 years mainly had upper and lower limb injuries. Contact with the bat/ball was the dominant mechanism of injury for those under 50 years of age while overexertion, strenuous or repetitive movements, slips and falls were the mechanisms for those over 50. The large number of head injuries to children is of concern and both these, and the substantial number of injuries to the hand/phalanges (63% of all upper limb injuries), are important targets for injury prevention. The difference in injury patterns between children and adults is indicative of a need to develop, and use, different types of PPE at different skill/age levels.

Playing conditions, player preparation and rugby injury: a case-control study.

This paper investigates the effect of player preparation, ground conditions and weather conditions upon the injury risk for Rugby Union players. A population-based case-control study was performed using a sample (n= 1043) of New Zealand Rugby Union players aged 16 y and above. Details concerning game preparation (warm-up and usual position), and ground and weather conditions (precipitation, wind and temperature) were obtained from the players. If players were injured during the season (n= 624) they were asked to provide details about the game in which they were last injured. Uninjured players (n= 419) provided details about the last game in which they played. Injuries were more likely to occur when games were played on hard grounds or in calm or warm conditions. Playing out of position and the duration of warming up did not significantly alter the risk of injury. When player preparation, ground and weather conditions, grade, age, playing position and rugby experience were simultaneously controlled for, hard ground and the absence of wind were associated with increased risk. The influence of these factors may be indirect, through adaptation to the conditions in which a game is played.

An evaluation of mouthguard requirements and dental injuries in New Zealand rugby union.

OBJECTIVES: To document the effects of compulsory mouthguard wearing on rugby related dental injury claims made to ACC, the administrator of New Zealand's accident compensation scheme. METHODS: An ecological study was conducted. Estimates of mouthguard wearing rates were available from prospective studies conducted in 1993, 2002, and 2003. Rugby related dental injury claims were available for the period 1995-2003. Player numbers were available from 1998. Mouthguard wearing was made compulsory during match play for rugby players at under 19 level and below at the beginning of the 1997 season, and for all grades of domestic rugby at the beginning of the 1998 season. Greater powers of enforcement were provided to referees at the beginning of the 2003 season. RESULTS: The self reported rate of mouthguard use was 67% of player-weeks in 1993 and 93% in 2003. A total of 2644 claims was reported in 1995. There was a 43% (90% confidence interval 39% to 46%) reduction in dental claims from 1995 to 2003. On the reasonable assumption that the number of players and player-matches remained constant throughout the study period, the relative rate of injury claims for non-wearers versus wearers was 4.6 (90% confidence interval 3.8 to 5.6). The cumulative savings in claim costs compared with the cost per year if claim numbers had remained constant from 1995 is 1.87 million NZD. CONCLUSION: Although ecological studies have acknowledged weaknesses, the findings provide evidence that mouthguard use is a simple and effective injury prevention strategy for rugby players. The use of mouthguards for all players in both matches and contact practice situations is strongly recommended.

Tackling Rugby injury: lessons learned from the implementation of a five-year sports injury prevention program.

Rugby Union football is a very popular sport in New Zealand but of all the major sports played in that country, it has the highest reported incidence of injury. In 1995, a national rugby injury prevention program was instigated to address this problem. Known as Tackling Rugby Injury, this multifaceted program was implemented over a five-year period. The program was based on the results of a prospective cohort study of rugby injury, known as the Rugby Injury and Performance Project (RIPP), and was organised around seven themes, five relating to the prevention of injury: coaching, fitness, injury management, tackling, and foul play, and two relating to the implementation and evaluation of the program. The purpose of this paper is to describe the lessons learned from the implementation of Tackling Rugby Injury. Qualitative research methods were used to describe the process of implementation, including informant interviews, participant observation, and the scrutiny of written, visual and archival material. Among the lessons learned were the importance of basing injury prevention strategies on scientific evidence rather than popular belief, the difficulty in implementing complex interventions, the advantages of a formal agreement between partners in the implementation of a program, the central role played by coaches in promoting injury prevention strategies, and the value of describing the process of implementation as well as monitoring injury outcomes and changes in knowledge, attitudes and behaviour. It is hoped that other sports wishing to develop injury prevention programs can learn from this experience.

Examining child restraint use and barriers to their use: lessons from a pilot study.

OBJECTIVE: To determine the suitability of four research methods to measure the rate of child restraint device (CRD) use and incorrect use in New Zealand and obtain data on barriers to CRD use. DESIGN AND SETTING: To assess the rates of CRD use among vehicles carrying children 8 years of age and under, two methods were piloted-namely, an unobtrusive observational survey and a short interview and close inspection. A self administered questionnaire and focus group interviews were also piloted to assess CRD use, reasons for use and non-use, and to obtain information on barriers to their use. Respondents to all methods except the focus groups were approached in supermarket car park sites at randomly selected times. Focus groups were established with parents identified through early childhood organisations. All methods were assessed on criteria related to efficiency, representativeness, and ability to obtain the necessary data. RESULTS: The observational survey provided a simple method for identifying rates of CRD use, while the self administered questionnaire obtained data on demographic characteristics and reported the installation and use/non-use of CRDs. The interview/inspection addressed all the questions of both the above methods and enabled incorrect CRD use to be examined. The focus groups provided the most meaningful information of all methods on barriers to CRD use. DISCUSSION: and conclusion: Advantages and limitations of these methods are discussed and some refinements of the original instruments are proposed. The interview/inspection and focus group methods were identified as being more appropriate for efficiently obtaining reliable data on CRD use and identification of barriers to CRD use.

Biomechanical analysis of arm fracture in obese boys.

OBJECTIVE: To determine the role of the biomechanical factors of force of impact, bone strength, fall height and surface stiffness on the risk of forearm fracture in obese children compared to non-obese children. METHODOLOGY: Anthropometric and dual-energy X-ray absorptiometry bone density data from 50 boys (25 obese pair-matched with 25 non-obese subjects) aged 4-17 years were entered into a rheological-stochastic simulation model of arm impact. RESULTS: Obese children were shown to be at 1.7 times greater risk of fracture compared to non-obese children. Lower fall heights and softer impact surfaces were found not to reduce the relative risk of fracture between obese and non-obese children. CONCLUSIONS: Environmental modifications are unlikely to lower the risk of arm fracture in obese children to the same levels experienced by non-obese children. The best option available for obese children to reduce fracture risk is to take steps to attain a healthy bodyweight.

Rugby headgear study.

A two year randomised controlled trial of headgear in Rugby Union football is being conducted in Sydney, Australia. This paper gives an overview of this study in progress and presents results related to the development and laboratory performance of the headgear. The study commenced in 2002. Participants recruited to the study are in the under 13, 15, school open (U18) and colts age groups. There are three study arms: control, IRB-approved headgear, and modified headgear. The IRB approved headgear is a popular model in rugby, the Canterbury Honeycomb model manufactured by BodyArmour in New Zealand. The dimensions of this model were altered by increasing foam density and thickness to produce the modified headgear. In impact energy attenuation tests of 15 and 20 Joules onto a flat anvil, the modified headgear demonstrated average maximum headform accelerations of 23% and 33% of the standard model, respectively. Whether or not this improvement translates into reductions in injury will be determined by a comparison of the rates and severities of head injuries across study arms. Furthermore, these dimensional changes may not be acceptable to rugby players. Player attitudes towards safety and the use of protective clothing, injury history, experience and on-field behaviour will be examined via structured pre- and end of season surveys and analysis of match video.

Injury prevention in sport: not yet part of the game?

BACKGROUND: There is a saying in sport that "injury is just part of the game". In other words, injury in sport is seen as inevitable. OBJECTIVE: To examine progress toward reaching the contrary position that "injury prevention is just part of the game". METHODS: The four steps of van Mechelen's "sequence of prevention" model provide a structure for examining progress. RESULTS: What is known about the size of the problem (step 1)? Most is known about more serious injuries and about injuries in élite and professional sport. Least is known about less serious injuries, injury in community level and amateur sport, and injury occurring in recreational activities. What is known about risk factors (step 2)? Despite calls for analytic studies since the early 1980s, few such studies have been reported in the literature. What is known about the effectiveness of preventive measures (step 3)? Few randomized controlled trials have been reported in the literature. Are there systems in place to monitor sports injury (step 4)? Examples are given of systems in North America, Europe, and Australasia. CONCLUSIONS: With a few exceptions, progress has not gone beyond step 1 in van Mechelen's model. Challenges for the future include: deciding where research efforts should be placed, standardization of definitions and methods of data collection and reporting, identification of risk factors and mechanisms of injury, and the evaluation of interventions. Finally, if the field of sports injury prevention is to advance, multidisciplinary collaboration will be required, along with the involvement of the sports community.

Infant-furniture-related injuries among preschool children in New Zealand, 1987-1996.

OBJECTIVE: To describe the epidemiology of infant-furniture-related fatalities and hospitalizations in New Zealand, for children aged 0-4 years. METHODS: Infant-furniture-related deaths and hospitalizations were selected from the New Zealand Health Information Service databases for the 10-year period 1987-1996. Intentional injuries were excluded. RESULTS: Forty-three fatalities were identified. Twenty-two fatalities (51%) occurred in cots, while 13 (30%) occurred in beds. Other products involved were prams, push chairs, high chairs, car seats, portable cots and walkers. A total of 1679 infants were hospitalized through infant-furniture-related injuries. Increasing trends in hospitalizations for baby walkers, beds and bunks were observed. CONCLUSIONS: On average, four infants die each year from injuries related to infant furniture, and hospitalizations from injuries associated with infant furniture use are increasing. Mandatory standards are one measure to reduce these numbers, but education is also necessary.

Adolescent injury morbidity in New Zealand, 1987-96.

OBJECTIVES: Adolescents are over-represented in injury statistics. New Zealand is privileged in having a hospital discharge database allowing for analysis of non-fatal injury data at a national level. An epidemiological description of adolescent injury morbidity is provided and options for prevention are discussed. METHOD: People aged 15-19 years admitted to hospital for their injuries in the period 1 987-96 were identified from the New Zealand Health Information Service morbidity data files. The manner, causes, and nature of injury were examined. Injury prevention strategies were reviewed. RESULTS: The incidence of hospitalised injury was 1,886 per 100,000 person years. The victims were male (70%). The leading causes of injury were road traffic crashes, sports injuries, and self poisoning. The most common injury diagnoses were head injuries (29%) and limb fractures (21%). Road traffic crashes produced the highest proportion of serious injuries. CONCLUSIONS: Road traffic crashes, sports injuries, and self inflicted poisoning, stood out as areas with the greatest potential for reducing the burden of injury in late adolescence. Graduated driver licensing shows promise as an injury prevention measure but remains inadequately implemented. Policies to reduce self inflicted poisoning are of unknown efficacy, and evidence is awaited on the effectiveness of measures to reduce injury in sport.

Shopping trolley-related injuries to children in New Zealand, 1988-97.

OBJECTIVE: To describe the epidemiology of shopping trolley related injuries (fatalities and hospitalizations) to children in New Zealand prior to the introduction of a voluntary standard for shopping trolleys. METHODOLOGY: To identify cases, a key word search was conducted of national mortality and hospitalization databases for the years 1988-97. Cases were limited to children under 15 years of age. RESULTS: For the 10 year period investigated, 282 hospitalizations and no fatalities were identified. A significant increasing trend for hospitalizations was detected (chi2 = 17.6, 1 d.f.; P < 0.001). Ninety-two per cent of children hospitalized were aged under 5 years and two-thirds were aged 2 years or younger. Ninety per cent of injuries resulted from falls from trolleys, 84% of injuries were to the head or face and 22% were rated serious (AIS-3) on the Abbreviated Injury Scale. CONCLUSIONS: The incidence of injuries associated with shopping trolleys increased between 1988 and 1997. Following the introduction of a voluntary standard for shopping trolleys in 1999, which included specifications for child harnesses, trends in injury should be monitored.

Use of protective equipment in a cohort of rugby players.

PURPOSE: To describe the level of usage of protective devices and equipment in a cohort of New Zealand rugby players. METHODS: Male and female players (N = 327) from a range of competitive grades were followed over the course of the season. Participants were interviewed weekly about their participation in rugby and use of protective equipment. The main outcome measure was percentage of all player-weeks of follow-up for which each equipment item was used. RESULTS: Mouthguards, the most commonly used equipment item, were worn for 64.9% of player-weeks. Mouthguard usage ranged from 55.0% of player-weeks in Schoolgirls grade to 72.9% of player-weeks in Senior A competition. The next most common item was taping of body joints (23.7% of player-weeks). The sites most commonly taped were the ankle, knee, and hand. Overall usage for the other protective equipment items studied (shin guards, padded headgear, head tape, support sleeves, and grease) was below 15%. In general, forwards had higher usage of protective equipment than backs, and male players had higher usage than female players. The most common self-reported reasons for using protective equipment were to prevent injury and because of a past injury. Players exhibited considerable week-to-week variation in their usage of protective equipment. CONCLUSIONS: In general, equipment usage was highest in those at greatest risk of injury, namely, forwards, male players, and the senior grades. The high voluntary use of mouthguards is encouraging and indicative of a base of player support for their role in this sport.

Compliance of Dunedin school playground equipment with the New Zealand playground standard.

OBJECTIVE: Injuries resulting from falls from playground equipment are a public health concern in New Zealand. Like many other countries, New Zealand has a safety standard aimed at reducing the incidence and severity of these injuries by limiting the height from which children can fall from playground equipment and requiring the provision of impact-absorbing surfaces beneath equipment from which falls are possible. The purpose of this study was to examine progress towards achieving compliance with these requirements in Dunedin school playgrounds. METHODS: Sixty-two schools were audited over the summer of 1997/98 and information recorded on equipment type, maximum fall height, surface type, and depth of loose-fill surface materials. Comparisons were made with audits conducted in 1989 and 1981. RESULTS: Substantial increases in the amount of playground equipment and in the provision of impact-absorbing surfaces were observed. A small increase in compliance with the requirement that the maximum fall height of equipment not exceed 2.5 metres was also observed. CONCLUSIONS: Any gains in safety achieved through increased compliance with the height and surface requirements of the New Zealand Standard have been counteracted by the substantial increase in the amount of equipment available in playgrounds. IMPLICATIONS: A more drastic measure is needed to achieve a meaningful reduction in the incidence of injury following falls from playground equipment.

Child injury morbidity in New Zealand, 1987-1996.

OBJECTIVES: New Zealand is one of a small number of countries that has a national hospital discharge database. The aim of this study was to use these data to provide an epidemiological description of child injury morbidity and to discuss options for prevention. METHODOLOGY: Using national data, all public hospital admissions for the fiscal year 1995/6 were identified and grouped according to cause. This allowed identification of all children (0-14 years) hospitalized for injury in the period 1987-1996. Causes of injury, diagnoses and injury severity were examined in four age groups. RESULTS: Injury was the second leading cause of public hospital admissions. Children were hospitalized with injury at the rate of 1333 per 100 000 person-years. The victims were predominantly male (61%). In all age groups, falls were the leading cause of morbidity. 'Striking events', motor vehicle traffic crashes and poisoning were also major contributors to the child injury toll. The commonest injury diagnosis was a fracture of the upper limb (25%), followed by intracranial injury (18%). CONCLUSIONS: The leading causes of injury morbidity were noted to differ from previously reported leading causes of injury mortality. Review of the data in light of research literature suggests the need for policy changes to make alternatives to motor vehicle transportation safer and to encourage increased use of child restraints in order to reduce road traffic trauma. Legislation requiring child-resistant packaging for all toxic medications and household products is necessary to reduce rates of child poisoning. Further research is required on policies concerning playground equipment heights and surfacing requirements, and on interventions for hot water scalds.

The New Zealand rugby injury and performance project. VI. A prospective cohort study of risk factors for injury in rugby union football.

OBJECTIVES: Although the nature of rugby injury has been well documented, little is known about key risk factors. A prospective cohort study was undertaken to examine the association between potential risk factors and injury risk, measured both as an injury incidence rate and as a proportion of the playing season missed. The latter measure incorporates a measure of injury severity. METHODS: A cohort of 258 male players (mean (SD) age 20.6 (3.7) years) were followed through a full competitive season. At a preseason assessment, basic characteristics, health and lifestyle patterns, playing experience, injury experience, training patterns, and anthropometric characteristics were recorded, and then a battery of fitness tests were carried out. RESULTS: A multiple regression model identified grade and previous injury experience as risk factors for in season injury, measured as an injury incidence rate. A second model identified previous injury experience, hours of strenuous physical activity a week, playing position, cigarette smoking status, body mass index, years of rugby participation, stress, aerobic and anaerobic performance, and number of push ups as risk factors for in season injury, measured as proportion of season missed. CONCLUSIONS: The findings emphasise the importance of previous injury as a predictor of injury incidence and of missing play. They also show the importance of considering both the incidence rate and severity of injury when identifying risk factors for injury in sport.