Objective To study the relationship between potentially game-disrupting incidents (PGDIs; red and yellow cards, goals and injuries) and the injury incidence in football.

Design Prospective injury surveillance during three FIFA World Cups in 2002, 2006 and 2010. Official match statistics were obtained for all the matches played in the three tournaments.

Setting 2002, 2006 and 2010 FIFA World Cups.

Participants Team physicians at the 2002, 2006 and 2010 FIFA World Cups.

Main outcome measures Injury incidences and incidence rate ratios (IRRs).

Results The injury incidence was significantly higher during match periods within the minute of, or during a five-minute period following a yellow card, red card, another injury or a goal (PGDIs) than during other match periods (76.7/1000 match hours; 95% CI (66.6 to 87.9) vs 54.0/1000 match hours (46.9 to 61.9), p<0.001). There were significant differences in injury incidence between different match periods, with the highest injury incidence seen in the last 15 min of the first half (p<0.001). The PGDIs (other than injury) had a tendency to increase towards the end of the game and the most frequent PGDI was a yellow card. There was a risk ratio of 1.17 (95% CI 1.08 to 1.26) for injury, per PGDI (other injuries excluded) (p<0.001), and 1.15 (95% CI 1.06 to 1.24) after adjusted match time (p<0.001).

Conclusions The injury incidence is high within the five minutes following a PGDI. For both team management and players, being aware of the increased risk of injury directly after a PGDI may be of clinical relevance, as it may enable them to take precautions in order to prevent injuries. There are significant differences in injury incidence between different match periods and game-related factors, such as PGDIs, appear partly to contribute to this variation.