Consensus Statement on Injury Definitions and Data Collection Procedures for Studies of Injuries in Rugby Union

Abstract

Wide variations in the definitions and methodologies used for studies of injuries in rugby union have created inconsistencies in reported data and made interstudy comparisons of results difficult. The International Rugby Board established a Rugby Injury Consensus Group (RICG) to agree on appropriate definitions and methodologies to standardize the recording of injuries and reporting of studies in rugby union. The RICG reviewed the consensus definitions and methodologies previously published for football (soccer) at a meeting in Dublin to assess their suitability for and application to rugby union. Following this meeting, iterative draft statements were prepared and circulated to members of the RICG for comment; a follow-up meeting was arranged in Dublin at which time all definitions and procedures were finalized. At this stage, all authors confirmed their agreement with the consensus statement. The agreed-on document was presented to and approved by the International Rugby Board Council.

Agreement was reached on definitions for injury, recurrent injury, nonfatal catastrophic injury, and training and match exposures together with criteria for classifying injuries in terms of severity, location, type, diagnosis, and causation. The definitions and methodology presented in this consensus statement for rugby union are similar to those proposed for football. Adoption of the proposals presented in this consensus statement should ensure that more consistent and comparable results will be obtained from studies of injuries within rugby union.

INTRODUCTION

Wide variations in the definitions and methodologies used for investigations of injuries in rugby union have created inconsistencies in reported data, which has in turn limited the value of individual studies and severely restricted opportunities for making interstudy comparisons of results. Recent consensus statements on injury definitions and procedures for cricket¹ and football (soccer)² have demonstrated an international recognition of the benefits that are gained from the use of common definitions and methodologies. The aim of this consensus statement is to establish operational definitions and methodologies for studies of injuries in rugby union.

METHOD

A preliminary review of the consensus statement produced for cricket¹ identified that these proposals were cricket-specific and would not translate readily into the rugby union environment. The consensus statement from football,² however, showed similarities with definitions and methodologies previously used in peer-reviewed publications of studies of rugby union injuries. The International Rugby Board (iRB) Medical Advisory Committee, therefore, established a Rugby Injury Consensus Group (RICG) to make a detailed assessment of the methodology proposed for football and to determine whether these proposals could be adopted within rugby union and, if this was not possible, to develop proposals that were appropriate for rugby union.

The RICG was composed of 7 voting members-namely, the Chief Medical Officer of the iRB, who acted as group Chairman, and representatives of 6 national rugby unions (3 from the Northern and 3 from the Southern Hemisphere). Six nonvoting members with experience in the study of injuries in a range of team sports were co-opted into the group to provide a wider perspective and a greater understanding of the issues involved. Prior to the initial meeting in Dublin, each member of the RICG was provided with a copy of the football consensus statement² to ensure that they were familiar with the issues to be discussed. The recommendations proposed by Fink et al³ for consensus group working were adopted during a 12 hour meeting. Each definition and methodological issue presented in the football consensus statement was introduced and discussed by the group. Depending on the outcome from these discussions, it was proposed that either the recommendation from the football consensus group should be accepted or alternative options were presented for consideration. Following this meeting, iterative draft consensus statements were prepared and each was circulated to members of the group for comment. A follow-up meeting was held in Dublin to finalize the definitions and procedures presented in this statement. At this stage, all authors confirmed their agreement with the definitions and procedures presented in this consensus statement. The agreed-on document was finally presented to and approved by the International Rugby Board Council.

DISCUSSION

The RICG endorsed the overall philosophy and broadly agreed on the details of the consensus statement presented for football² but, because of the inherent differences between the games of rugby union and football, it was considered that some changes were required. For clarity, definitions are presented here in the context of rugby union; however, it was not considered necessary to re-present comments on issues where there was agreement with the football statement. Therefore, unless specifically stated to the contrary, it should be assumed that the methodologies and explanatory notes contained in the football consensus statement form an integral part of this consensus statement for rugby union. The following discussion focuses on those issues where the consensus statement for rugby union departs from the statement presented for football. For comparability and ease of cross-referencing between the 2 documents, the issues are presented and discussed in the same order as that used in the football consensus statement.²

DEFINITIONS

Definitions of injury can be broadly categorized into theoretical and operational definitions⁴: in studies of sports injuries, definitions are normally intended to provide pragmatic or operational criteria for recording cases rather than to provide a theoretical definition of injury. Although there is no generally accepted theoretical definition of an injury because of its dependence on context,⁴ definitions are broadly based around the concept of “bodily damage caused by a transfer or absence of energy.” This general concept may be helpful for clarifying whether an incident in rugby should be recorded as an injury.

Injury

The following definition of injury was accepted:

Any physical complaint, which was caused by a transfer of energy that exceeded the body's ability to maintain its structural and/or functional integrity, that was sustained by a player during a rugby match or rugby training, irrespective of the need for medical attention or time-loss from rugby activities. An injury that results in a player receiving medical attention is referred to as a “medical-attention” injury and an injury that results in a player being unable to take a full part in future rugby training or match play as a “time-loss” injury.

In rugby union, nonfatal catastrophic injuries are of particular interest; therefore, a third subgroup of reportable injuries was added:

A brain or spinal cord injury that results in permanent (>12 months) severe functional disability is referred to as a “non-fatal catastrophic injury.”

Severe functional disability is defined by the World Health Organization⁵ as a loss of more than 50% of the capability of the structure.

Recurrent Injury

The definition of recurrent injury was accepted:

An injury of the same type and at the same site as an index injury and which occurs after a player's return to full participation from the index injury. A recurrent injury occurring within 2 months of a player's return to full participation is referred to as an “early recurrence”; one occurring 2 to 12 months after a player's return to full participation as a “late recurrence”; and one occurring more than 12 months after a player's return to full participation as a “delayed recurrence.”

In rugby union studies, however, a sutured laceration that is reopened during a match or training session should be considered to be a recurrence.

Injury Severity

Time (days) lost from competition and practice was accepted as the basis for defining injury severity:

The number of days that have elapsed from the date of injury to the date of the player's return to full participation in team training and availability for match selection.

Injuries should be grouped, therefore, as slight (0-1 days), minimal (2-3 days), mild (4-7 days), moderate (8-28 days), severe (>28 days), “career-ending,” and “nonfatal catastrophic injuries.”

Match Exposure

The definition of match exposure was accepted:

Play between teams from different clubs.

However, in rugby union, it is a common practice for clubs and countries to use competitive matches between “A” and “B” teams as trials for selection purposes. In these cases, “A” and “B” trial teams should be treated as though they were separate clubs and, in the case of fully refereed competitive trial matches between these teams, the exposure should be recorded as match exposure.

Training Exposure

The definition of training exposure was accepted:

Team-based and individual physical activities under the control or guidance of the team's coaching or fitness staff that are aimed at maintaining or improving players' rugby skills or physical condition.

METHODOLOGICAL ISSUES

The proposal that injury surveillance studies should, wherever possible, be prospective cohort studies was endorsed. In practical terms, most injury surveillance studies in rugby union will record “time-loss” and “nonfatal catastrophic” injuries. Because of the physical nature of rugby union and the high number of slight contusions routinely encountered in the game, studies in rugby union will normally only record injuries as “time-loss injuries” if they result in more than 1 day of absence from training, matches, or both. The nature of the game of rugby union means that recording injuries will often be more complex than is the case for football; for example, multiple injury diagnoses from a single event and multiple events (with or without multiple diagnoses) involving the same player in the same game are more common in rugby union.

Interpretation of Injury Definition

Studies should not incorporate mixed definitions of injury; it is anticipated that most studies in rugby union will record “time-loss” injuries. A “blood injury” that requires a player to leave the field of play for treatment under Law 3.11(a) should not be included as an injury in a study unless the player subsequently loses time from training or competition as a result of the injury. If, however, the purpose of a study is to record the incidence of “blood injuries,” then these injuries should be recorded and reported separately from “time-loss” injuries. Examples of how specific incidents should be recorded using the “medical attention” and “time-loss (>1 day severity)” regimens are presented in Table 1.

TABLE 1: Examples of How to Record Injuries Under a “Time-Loss” Recording Regimen

Nonfatal catastrophic injuries (permanent severe functional disability) should not include injuries resulting in transient neurologic deficits such as burners/stingers, paresthesias, transient quadriplegia, and cases of concussion where there is full recovery.

Injury Classification

The requirement that injuries should be classified by location, type, body side, and injury event was endorsed.

Location of Injury

The main groupings and categories proposed were accepted with the additional requirement that the category of “thigh injury” should be subdivided into “anterior thigh” and “posterior thigh” injuries.

Type of Injury

The categories proposed for reporting the type of injury sustained were broadly accepted. However, the headings used for the main groupings were subject to slight change and additional categories within these groupings were added to reflect the injury profile in rugby union-namely, injuries to the head, spinal cord, and internal organs. For clarity, the full list of main groupings and categories that should be used in rugby union is shown in Table 2.

TABLE 2: Main Groupings and Categories for Classifying the Type of Injury

Other Injury Classification Issues

Injuries should be classified as to whether they occurred during a match or training session and whether they were the result of contact with another player or object or were a noncontact injury. For injuries resulting from contact, activities should be recorded as tackling, tackled, maul, ruck, lineout, scrum, collision, or other. It may also be appropriate to record whether the action causing the injury was deemed by the match referee to be a violation of the laws of the game or was deemed by the match referee or citing official to be “dangerous play” (Law 10.4).

Study Population

The RICG endorsed the view that injury surveillance studies should normally include players from more than 1 team and should extend for a minimum period of 1 season or 1 year or for the duration of a major tournament.

Implementation Issues

The format and content of studies should be approved by an appropriate institutional ethics committee, and informed consent should be obtained from all players for their data to be included in the study. The formats of the proforma provided in the football consensus statement² were accepted as appropriate for use in rugby union. For rugby union, the player's dominant arm should also be identified on the Player's baseline information form because of the importance and higher incidence of upper-limb injuries in rugby union. Appendix A provides an example of an injury form for use within rugby union.

For studies in rugby union that record team match exposure, the total player-match exposure time in hours for a team is given by {N_M × P_M × D_M/60} where N_M is the number of team-matches played, P_M is the number of players in the team (normally 15), and D_M is the duration of the match in minutes (normally 80).

Reporting Data

The RICG endorsed the view that the incidence of match and training injuries should be reported separately; in addition, injury profiles should be reported separately for match and training injuries. If the times of match injuries are recorded, the injuries should be grouped into quarters, which would normally be as follows: first half: 0-20, 21-40+; second half: 41-60, 61-80+ minutes. When available, the official match clock-time should be used for recording the time of injury.

CONCLUSIONS

The definitions and methodology presented in the consensus statement for football were found generally to be appropriate for rugby union. Minor variations in some definitions and procedures were required, however, to reflect specific issues associated with rugby union. The definitions and procedures presented in this consensus statement should improve the quality of data collected and reported in future studies of rugby union injuries. In addition, the adoption of broadly similar definitions and methodologies across sports should enable meaningful intersport comparisons of results to be made. Finally, the definitions and methodologies presented in this consensus statement will form the basis for all future studies of injuries supported by the iRB.