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Data collection procedures for football injuries in lower leagues: Is there a need for an updated consensus statement?

The football consensus statement was published in 2006 with recommended data collection procedures and reporting standards for studies of injuries in football (Fuller et al. 2006). Since its publication (parallel in three sports medicine journals), it has been cited >450 times (Web of Science) indicating high adoption within the scientific community. McCunn et al. (2016) in their article raise the question whether there is now a need for an updated consensus statement to better adapt to studies on “part-time” players, e.g., at youth and recreational levels. Indeed, for cricket, the first sport to publish guidelines for injury surveillance in 2005, there was a recent 2016 update of the consensus statement (Orchard et al. 2016). This update was mainly driven by two factors: (1) there had not been universal uptake of the injury definition proposed in the original consensus statement (a more “narrow” match time-loss definition) and (2) the increasing popularity of a new short form of cricket, the T20, to which the original definitions were less applicable. While no such issues seem apparent for football, McCunn et al. (2016) suggest two main topics that need clarification for studies in lower-level players: (1) who should record data and (2) how should severity be quantified? Themain challenges addressed in the discussion piece are the lesser resources for data collection, particularly access to qualified medical practitioners to assess injuries, and difficulties in quantifying injury severity based on time-loss from play due to infrequent training and match activities. There are of course several examples of successful surveillance studies in lowerlevel football carried out within the framework of the consensus statement, using coach or player reporting (e.g., Soligard et al. 2008; Clausen et al. 2014). In these cases it is important to recognize that injury reporting should be restricted to regional diagnoses (e.g., ankle, knee) and general injury circumstances (e.g., contact/noncontact, acute/gradual onset). Alternative approaches to quantifying injury severity based on reduction in training volume or performance, and experienced pain, have also been developed (Clarsen et al. 2013). I believe a key point is that depending on the overall aim of the injury surveillance (e.g., implementation of long-term surveillance within a sport, or study specific), the research question in focus, study context, and available resources, different injury definitions and data collection procedures may be optimal. This means that each study must report in detail the injury surveillance methods used (not just refer to a consensus), and preferably report injury rates at multiple levels, to facilitate inter-study comparisons. Another important point we as football injury researchers must consider is that even with a consensus statement in place, the perhaps biggest challenge is to operationalize these definitions and methods in the clubs/players that collect data. Large variations in injury rates are often found between clubs even within the same study cohort. For instance, we previously reported from our long-term injury surveillance of top-level European football a range of 12 to 121 documented time-loss injuries per club per season (Hägglund et al. 2013). It is likely that, in addition to true variations in injury rates, these inter-club variations reflect differences in medical strategies in the clubs (e.g., whether to sit a player out or continue to play) as well as differences in how injuries and exposures are reported. Having a detailed manual and training of data collectors is important, as is implementing a feasible data collection system. Another key to strengthening themethodological quality of injury surveillance is to have a controller in the research group who continuously checks reported data. This includes having regular communication with the data collectors to facilitate reporting compliance and accuracy. So, while an updated consensus statement may broaden its applicability further, there is also much work to be done within the current framework to increase quality and consistency in data collection and reporting.