The Oslo Sports Trauma Research Center questionnaire [624312]

The Oslo Sports Trauma Research Center questionnaire
on health problems: a new approach to prospective
monitoring of illness and injury in elite athletes
Benjamin Clarsen,1Ola Rønsen,2Grethe Myklebust,1Tonje Wåle Flørenes,1
Roald Bahr1
▸Additional material is
published online only. To view
please visit the journal online
(http://dx.doi.org/10.1136/
bjsports-2012-092087).
1Oslo Sports Trauma Research
Center, Norwegian School of
Sport Sciences, Oslo, Norway
2The Olympic Elite Sports
Program (Olympiatoppen),
Oslo, Norway
Correspondence to
Benjamin Clarsen, Department
of Sports Medicine, Oslo SportsTrauma Research Center,Norwegian School of Sport
Sciences, PB 4014 Ullevål
Stadion, Oslo 0806, Norway;[anonimizat]
Received 13 December 2012
Revised 4 February 2013
Accepted 5 February 2013Published Online First21 February 2013
To cite: Clarsen B,
Rønsen O, Myklebust G,et al.Br J Sports Med
2014; 48:754–760.ABSTRACT
Background Little information exists on the illness
and injury patterns of athletes preparing for the Olympicand Paralympic Games. Among the possible explanationsfor the current lack of knowledge are the methodologicalchallenges faced in conducting prospective studies oflarge, heterogeneous groups of athletes, particularlywhen overuse injuries and illnesses are of concern.Objective To describe a new surveillance method that
is capable of recording all types of health problems andto use it to study the illness and injury patterns ofNorwegian athletes preparing for the 2012 Olympicand Paralympic Games.Methods A total of 142 athletes were monitored over
a 40-week period using a weekly online questionnaireon health problems. Team medical personnel were usedto classify and diagnose all reported complaints.Results A total of 617 health problems were registered
during the project, including 329 illnesses and 288injuries. At any given time, 36% of athletes had healthproblems (95% CI 34% to 38%) and 15% of athletes(95% CI 14% to 16%) had substantial problems,defined as those leading to moderate or severe
reductions in sports performance or participation, or timeloss. Overuse injuries represented 49% of the totalburden of health problems, measured as the cumulativeseverity score, compared to illness (36%) and acuteinjuries (13%).
Conclusions The new method was sensitive and valid
in documenting the pattern of acute injuries, overuse
injuries and illnesses in a large, heterogeneous group ofathletes preparing for the Olympic and Paralympic Games.
INTRODUCTION
In recent years, the value of regular monitoring in
protecting the health of athletes has received increas-ing recognition.
12The International Olympic
Committee, together with several major InternationalFederations and National Olympic Committees, hasdeveloped a surveillance system designed to recordinjuries and illnesses in major championships,
3and
this has been successfully implemented in several
Olympic Games, W orld Championships and othermajor sporting tournaments.
4–11Similarly , the
International Paralympic Committee has conducted
systematic injury surveillance at the 2002, 2006 and2010 Winter Paralympic Games.
12–14However, with
the exception of certain sports such as football,15
there are few prospective studies of health problemsamong Olympic-level athletes outside of the briefperiod in which they are competing in major cham-pionships. Little is known, therefore, about theirpatterns of illness and injury in their normal trainingand preparation phases.
Among the possible explanations for this lack of
knowledge are the methodological challenges facedwhen conducting longer term studies in this groupof athletes. The methods currently employed in amajority of prospective surveillance studies arebased on those developed for recording footballinjuries,
16and while they may work well for team
sports, they are dif ficult to implement among
groups of individual athletes or those without acentralised team structure.
17Standard methods of
injury surveillance may also be poorly suited to col-lecting information on overuse conditions, whichrepresent the predominant injury type in manyOlympic sports.
10 18 –20W e have recently discussed
these limitations in detail,21made general recom-
mendations for more appropriate methodology21
and developed new tools that are better suited tothe study of overuse injuries.
22
Our first aim in the present study was therefore
to modify our new method22such that it can be
used to record not only overuse injuries but also alltypes of health problems in studies of large, hetero-geneous groups of athletes. Our second aim was toapply the method to analyse the patterns of illnessand injury in the Norwegian Olympic andParalympic teams during their preparations for the
2012 games in London.
METHODS
Recruitment
During the summer of 2011, the coaches of the
Norwegian national teams in all candidate sportsfor the London Olympic or Paralympic Gameswere asked to provide a list of athletes who had thepotential to qualify. The final list included 143 ath-
letes, 142 of whom gave their consent to partici-
pate in the project. This included 116 Olympiccandidates (54 male and 62 female) and 26Paralympic candidates (15 male and 11 female).The Olympic sports in the study included archery(n=1), athletics (n=22), beach volleyball (n=6),boxing (n=2), cycling (n=12), handball (n=24),kayak (n=7), rowing (n=13), sailing (n=8),shooting (n=5), swimming (n=10), taekwondo(n=3), weightlifting (n=1) and wrestling (n=2).The Paralympic sports included archery (n=1),athletics (n=1), boccia (n=1), cycling (n=2),equestrian (n=4), sailing (n=4), shooting (n=7),swimming (n=3) and table tennis (n=3). Themedical personnel that participated in classifyingand diagnosing illness and injuries included all the
Clarsen B, et al.Br J Sports Med 2014; 48:754 –760. doi:10.1136/bjsports-2012-092087 1 of 8Original article group.bmj.com on September 6, 2014 – Published by bjsm.bmj.com Downloaded from

doctors (n=7) and physiotherapists (n=13) who were selected
to travel with the Norwegian athletes to the Olympic orParalympic Games. The study was approved by the NorwegianData Inspectorate and reviewed by the South-Eastern NorwayRegional Committee for Research Ethics. Informed consent wasobtained from the athletes at the first registration.
Data collection procedure
Every Sunday for the duration of the project, we used onlinesurvey software (Questback V .9692, Questback AS, Oslo,Norway) to send all athletes an email linking them to an internet-based questionnaire on health problems, with an automaticreminder email 3 days later if needed ( figure 1). Each Thursday,
the project coordinator (BMC) compiled a report based on thequestionnaire responses from that week and sent it to the rele-vant team medical staff. They were then expected to follow-upeach case and, in addition to providing normal clinical manage-ment or advice to the athlete, to fill in a report classifying the
type and diagnosis of each health problem. These reports weresent back to the project coordinator on a monthly basis.
The Oslo Sports Trauma Research Center (OSTRC)
questionnaire on health problems
W e developed the Oslo Sports T rauma Research Center
(OSTRC) Questionnaire on Health Problems based on theOSTRC Overuse Injury Questionnaire.
22The four key questions
on the consequences of health problems on sports participation,training volume and sports performance as well as the degree towhich they have experienced symptoms were modi fied to
capture all types of health problems including illness and acute
injuries ( figure 2). If the athlete answered the minimum score
for each of these questions (full participation without problems/
no training reduction/no performance reduction/no symptoms),the questionnaire was finished for that week. However, if the
athlete reported anything other than the minimum value for any
question, the questionnaire continued by asking them to de fine
whether the problem they referred to was an illness or an injury.
In the case of an injury, they were asked to register the areaof the body in which it was located, and in the case of anillness, they were asked to select the major symptoms they hadexperienced. For all types of problems, the number of days ofcomplete time loss, de fined as the total inability to train or
compete, was also registered. Athletes were also asked whetheror not the problem had been reported previously, whether theproblem was already being treated (and by whom) and whetherthey had any further comments for their Olympic medical team.These three questions were included for use in the weeklyreports rather than for epidemiological data collection purposes.Finally, athletes were asked whether the problem they had beenreferring to was the only health problem they had experiencedduring the preceding 7 days or whether they had experiencedseveral problems. If they had only had one problem, the ques-tionnaire was finished, whereas if they reported several pro-
blems, the questionnaire returned to the four key questions and
repeated itself for each subsequent problem reported. The ques-tionnaire logic is summarised in figure 3, and the complete
Figure 1 Diagram showing the procedures used to collect data on
health problems.
Figure 2 The four key questions asked at the beginning of the
weekly online Oslo Sports Trauma Research Center (OSTRC)
Questionnaire on Health Problems. If the athlete answered the
minimum value in each of the four questions, the questionnaire wasfinished for that week.
2 of 8 Clarsen B, et al.Br J Sports Med 2014; 48:754 –760. doi:10.1136/bjsports-2012-092087Original article group.bmj.com on September 6, 2014 – Published by bjsm.bmj.com Downloaded from

OSTRC Questionnaire is available as an online supplement
appendix 1.
Classi fication and diagnosis of reported problems
T eam medical personnel were asked to classify each problem
reported as an illness, acute injury or overuse injury, based on their
clinical interview. In accordance with the International Olympic
Committee surveillance system,3health problems were classi fied as
injuries if they were disorders of t he musculoskeletal system or con-
cussions. They were classi fied as illnesses if they involved other
body systems, such as (but not limited to) the respiratory, digestiveand neurological systems, as well as non-speci fic/generalised, psy-
chological and social problems. Injuries were further subcategorisedinto overuse and acute injures. Acute injuries were de fined as those
whose onset could be linked to a speci fic injury event, whereas
overuse injuries were those that could not be linked to a clearlyidenti fiable event. The medical team was also asked to provide a
specific diagnosis for each event. For illnesses, the International
Classi fication of Primary Care, V .2 (ICPC-2) was used,
23and for
injuries the Orchard Sports Injury Classi fication System, V .10
(OSICS-10), was used.24Thefirst tier of the OSICS-10 code was
used to determine the location , and the second tier was used to
determine the type. The first letter of the ICPC-2 code was used to
determine the body system affected by illness.
At the conclusion of the project, the project coordinator
manually went through each athlete ’s questionnaire responses
and cross-checked all reported health problems with the classi fi-
cations and diagnoses made by the medical team. All cases were
checked twice for accuracy, and in 16 cases where informationwas missing or con flicting, medical personnel were contacted
for clarifi cation. In injury cases where the same diagnosis was
interspersed with periods of apparent recovery, medical person-
nel were consulted in order to classify subsequent events asexacerbations of unresolved problems or recurrences of fullyrecovered problems (reinjuries), in accordance with the de fini-
tions outlined by Fuller et al .
25Illnesses were treated in a
similar fashion, with repeated episodes of chronic conditionstreated as a single case for the purposes of analysis.Prevalence calculations
Prevalence measures were calculated for all health problems, ill-nesses, injuries, overuse injuries and acute injuries for each weekthat the project was conducted. This was performed by dividingthe number of athletes reporting any form of problem by thenumber of questionnaire respondents. The prevalence of sub-stantial problems was also calculated for each of these measures,with substantial problems de fined as those leading to moderate
or severe reductions in training volume, or moderate or severereductions in sports performance, or complete inability to par-ticipate in sport (ie, problems where athletes selected option 3,4 or 5 in either Questions 2 or 3). All prevalence measures werealso calculated for the four different subgroups of athletes:(1) team athletes (n=30), consisting of handball and beachvolleyball players; (2) endurance athletes (n=53), consisting ofathletes from cycling, kayak, rowing, swimming as well asthe middle-distance and long-distance runners from athletics;(3) tactical/technical athletes (n=36), consisting of athletesparticipating in archery, boxing, sailing, shooting, taekwondo,weightlifting and wrestling, as well as the sprint and field
athletes from athletics and (4) paralympic athletes (n=26). Allprevalence measures were presented as averages, together with a95% CI. Data from the first week the project was conducted
were excluded from all calculations, as per our previousrecommendations.
22
Severity of health problems
Each week, a severity score was calculated for all reportedhealth problems based on an athlete ’s responses to the four key
questions.
22The severity score was plotted in order to track
the progression of each health problem, such as in the exampleshown in figure 4. The cumulative severity score was then calcu-
lated for each case by summing the severity score for each weekthat it was reported. The average weekly severity score was calcu-
lated by dividing the cumulative severity score by the number ofweeks the problem was reported. The total amount of completetime loss was also calculated for each problem by summing
the weekly reported time loss. For all the above calculations,recurrent problems were counted as the same event if they weredeemed by the medical staff to be exacerbations of an unre-solved injury or a chronic illness.
Relative burden of illness, overuse injury and acute injury
The cumulative severity scores for all health problems weresummed, and the proportion of the total number made up byillness, overuse injury and acute injury was determined. Thiswas performed in order to estimate the relative burden of thesedifferent types of health problems.
Figure 3 Diagram of questionnaire logic showing how the length of
the questionnaire varied according to the number of health problems
the athlete reported. Up to four health problems could be reportedper week.
Figure 4 Example of the severity score being used to track the
consequences of three ‘typical ’health problems. The light grey area
represents a mild overuse injury (cumulative severity score: 352), the
dark grey area represents a short duration illness (91) and the area
with diagonal lines represents a severe acute injury (1005).
Clarsen B, et al.Br J Sports Med 2014; 48:754 –760. doi:10.1136/bjsports-2012-092087 3 of 8Original article group.bmj.com on September 6, 2014 – Published by bjsm.bmj.com Downloaded from

Statistical analyses
In order to analyse differences in the various prevalence
measures between subgroups of athletes, Kruscal-W allisnon-parametric analysis of variance (ANOV A) tests wereapplied, using SPSS statistical software (SPSS V .18, IBMCorporation, New York, USA).
In order to analyse differences in the duration, cumulative
severity and average weekly severity scores between differenttypes of health problems, as well as between diagnosed andundiagnosed health problems, regression analyses were made.The repeated nature of measurements was taken into account byapplying the robust option in the xtreg command in STATA stat-istical software (STATA V .12.0, StataCorp LP , T exas, USA). Thesignificance level ( α) was set at 0.05 for all tests.
As the original OSTRC questionnaire was developed for
recording injury consequences,
22it was necessary to reanalyse
the psychometric properties of the four key questions whenthey were applied to illnesses. In order to do this, all question-naires that did not report an injury (n=3384) were analysedusing SPSS software to determine internal consistency(Cronbach’ sα). A factor analysis was also performed using a
principle component analysis extraction method. Additionally,in order to assess the effects of sampling less frequently, theprimary outcome measures were recalculated using only infor-mation from every second and fourth questionnaires.RESULTS
Response rate to the weekly health questionnaires
The average weekly response rate to the health questionnaires
was 80% (SD 5). The rate was 84% (SD 3) among athletes thatwere eventually selected for participation in London, while itwas 75% (SD 10) among those that were not selected. Figure 5shows the response rates for each of these groups during thecourse of the 40-week project. As illustrated, the response fromnon-selected athletes fell during the second half of the project.
Classi fication of problems reported
A total of 617 health problems were reported by 132 athletesover the course of the 40-week project, including 329 illnessesand 288 injuries. Of these, 582 cases (94%) were followed upby medical staff and classi fied with an ICPC-2 or OSICS-10
code. A majority of the 35 unclassifi ed cases were brief and of
mild severity, with their average duration being shorter than thatof classi fied health problems (1 week (95% CI 1 to 2) vs
3 weeks (95% CI 3 to 3), p=0.03), and with their averagecumulative severity being substantially lower (51 (95% CI34 to 67) vs 118 (95% CI 99 to 137), p<0.01).
Prevalence of health problems
The average weekly prevalence of health problems reported was36% (95% CI 34% to 38%), with 15% of athletes reportingsubstantial health problems each week (95% CI 14 to 16). Asshown in table 1, overuse injury was the most prevalent type ofhealth problem, and there was a variation in the prevalence ofhealth problems between the various subgroups of athletes.
Over the course of the 40-week project, there was a general
decline in the prevalence of illness, substantial illness, overuseinjury and substantial overuse injury ( figure 6), while the preva-
lence of acute injury increased slightly over the same period.
Injury data
A total of 288 injuries were reported by 115 athletes over thecourse of the study . Of these, 202 were classi fied as overuse
injuries, 60 as acute injuries and 26 were unclassifi ed. The
average duration, average weekly severity score and averagecumulative injury score for acute and overuse injuries are shownin table 2. As shown in the table, there were no signi ficant
Figure 5 Response rate (%) to the weekly health questionnaires for
the whole group (solid grey area), for the athletes selected for the
Olympic and Paralympic Games (n=71, solid line) and for the athletes
not selected for participation in the games (n=71, dashed line).
Table 1 Average weekly prevalence (percentage of athletes affected) of all health problems and substantial problems reported, as well as the
prevalence of the subcategories illness, injury, overuse injury and acute injury in the whole group and each of the four subgroups of athletes
Team Endurance Tactical/technical Paralympic Total cohort
n=30 n=53 n=36 n=26 n=142
Health problems reported
All 45 (42 –48)**,***,**** 30 (27 –32)*,*** 25 (21 –28)*,** 29 (26 –33)* 36 (34 –38)
Illness 6 (5 –8)**,***,**** 16 (13 –18)*,*** 10 (9 –12)*,**,**** 16 (14 –19)*,*** 13 (12 –14)
Injury 42 (39 –45)**,***,**** 17 (16 –19)* 18 (14 –22)* 19 (17 –21)* 25 (24 –27)
Overuse injury 31 (29 –33)**,***,**** 15 (13 –17)* 16 (13 –18)* 13 (12 –14)*,** 20 (18 –21)
Acute injury 10 (8 –12)**,***,**** 2 (1 –2)* 3 (2 –4)* 2 (1 –3)* 4 (3 –5)
Substantial problems
All 16 (14 –17)*** 14 (13 –16)*** 11 (9 –13)*,**,**** 16 (14 –19)*** 15 (14 –16)
Illness 2 (1 –3)**,***,**** 8 (6 –10)* 6 (5 –8)* 8 (6 –10)* 6 (6 –7)
Injury 14 (13 –16)**,***,**** 7 (6 –7)* 5 (4 –7)*,**,**** 11 (9 –12)*,**,*** 9 (9 –10)
Overuse injury 9 (8 –11)**,*** 6 (5 –6)* 4 (3 –5)*,**,**** 10 (8 –11)**,*** 7 (6 –8)
Acute injury 5 (4 –6)**,***,**** 1 (0 –1)* 2 (1 –2)* 1 (0 –2)* 2 (2 –3)
p<0.05 vs *team group, **endurance group, ***tactical/technical group, ****paralympic group.
All data are mean values with 95% CI in parenthesis. Substantial problem: causing moderate/severe reductions in training volume or sports performance, or complete inability toparticipate in training or competition.
4 of 8 Clarsen B, et al.Br J Sports Med 2014; 48:754 –760. doi:10.1136/bjsports-2012-092087Original article group.bmj.com on September 6, 2014 – Published by bjsm.bmj.com Downloaded from

differences between the average duration, average weekly sever-
ity score or average cumulative severity score between overuseand acute injuries, although overuse injuries tended to lastlonger (p=0.055).
Of the 288 injuries reported, 122 were substantial problems,
including 86 overuse injuries and 27 acute injuries (9 wereunclassi fied; average duration: 1.3 weeks, SD 0.5).
The location of acute and overuse injuries and their severity
measured by time loss are shown in table 3. The most commonoveruse injury types were unspeci fied pain (29% of cases),
muscle injury (25%), tendon injury (16%) and synovitis/impingement/bursitis (15%), while the most common types ofacute injury were joint sprains (48%), muscle injury (15%) andbruising/haematoma (12%).
Illness data
A total of 329 illnesses were reported by 106 athletes over thecourse of the study, and 97% of cases were classi fied with an
ICPC-2 code. Of the 329 illnesses reported, 198 representedsubstantial problems. The average weekly prevalence of illnessand of substantial illness for the whole group and for eachsubgroup of athletes is shown in table 1. As shown in table 2,illnesses had a higher average weekly severity score than injuries.However, as their average duration was shorter, their averagecumulative severity score was signi ficantly lower. The most com-
monly affected systems were the respiratory system (68% of
cases) and the digestive system (16%).
Relative burden of illness, overuse injury and acute injury
When the cumulative severity score of all health problems was
summed, overuse injuries represented 49% of the total number,illnesses represented 36% and acute injuries represented 13%.The remaining 2% consisted of unclassifi ed injuries.
Psychometric questionnaire properties
The questionnaire had high internal consistency when allquestionnaires were analysed, as well as for non-injury cases(Cronbach’ sαof 0.96 and 0.97, respectively). This was
not improved by removing items in either case (table 4). Thefactor weighting was relatively even for all four questions inboth cases.
Effects of different sampling frequencies on outcome
measures
Sampling less frequently led to fewer cases being identi fied and
a reduction in the average cumulative severity score and dur-
ation. However, the average prevalence and average weeklyseverity measures were not affected (table 5).
DISCUSSION
This paper describes a new approach to monitor athletes’health, and presents the first prospective data on the illness and
injury patterns of Olympic and Paralympic athletes preparing forthe games. The main findings were that, at any given time, 36%
of athletes had some form of health problem, and 15% had asubstantial illness or injury. The new method was able to showthat overuse injuries represented the greatest burden on thegroup, owing to the large number of cases and the relatively longduration of consequences they had on the athletes’ participation
and performance. In contrast, illnesses were of signi ficantly
shorter duration and there were far fewer cases of acute injury.
The methods used in this study represent a modi fication of
those we developed for recording overuse injuries in prede fined
anatomical areas,
22such that they can be used to monitor all
types of health complaints. Although the previous approach ismore appropriate for the study of speci fic problems, such as
shoulder problems, the current approach is better suited togeneral surveillance studies, particularly when the cohort is het-erogeneous and a wide variety of complaints is expected. Inboth approaches, the methods differ considerably from thosetypically used in prospective surveillance studies as health pro-blems are reported directly by athletes through regular onlinequestionnaires, rather than via team medical staff. W e have pre-viously discussed the bene fits and limitations of this approach in
detail
21 22; therefore, this discussion will focus primarily on the
modi fications made in the current study.
One of the principal modi fications was to restructure OSTRC
questionnaire: The four key questions were made more general(referring to any health problem or complaint rather than a spe-
cific anatomical area) and logical functions were used to register
multiple problems. These changes were made to allow for theregistration of all types of problems and to minimise the timeburden of completing the questionnaire. However, in ourexperience, one of the limitations of trying to capture all pro-blems is that fewer are identi fied than when speci fic questioningTable 2 Average duration, weekly severity score and cumulative
severity score of illnesses, overuse injuries and acute injuries
Illness Overuse injury Acute injury
n=329 n=202 n=60
Duration (weeks) 2 (2 –2) 5 (4 –6)* 3 (2 –4)*
Average weekly severity score 45 (42 –47) 32 (29 –34)* 35 (30 –40)
Cumulative severity score 78 (69 –87) 169 (125 –214)* 153 (66 –240)*
*Significantly different to illness (p<0.03).
Data are mean values with the 95% CI in parenthesis.
Figure 6 Prevalence of illness, overuse injury and acute injury over
the 40-week study. Light grey area: all complaints (linear regression
line=long dashes), dark grey area: substantial problems (linearregression line=short dashes).
Clarsen B, et al.Br J Sports Med 2014; 48:754 –760. doi:10.1136/bjsports-2012-092087 5 of 8Original article group.bmj.com on September 6, 2014 – Published by bjsm.bmj.com Downloaded from

is used.19T o combat this, we structured the questionnaire such
that all athletes had to complete the four key questions regard-
less of whether or not they had any health problems to report.This prompted the athlete to consider the question have you
had any health problems in several different ways.
A second modi fication was the use of team medical staff to
classify and diagnose each health problem reported by athletes,allowing for the prospective collection of exact diagnoses, aswell as a comprehensive subclassi fication of each case. As this
method records all physical complaints, a considerable propor-tion of minor and transient cases are likely to be non-speci fico r
difficult to diagnose. This was the case in the current study,
where the most common type of overuse injury was ‘unspeci fied
pain, ’representing 29% of all cases. Nevertheless, monitoring
the prevalence of speci fic injury types, such as tendinopathy or
stress fractures, becomes possible using this approach. In add-ition, the system of weekly feedback reports to team medicalstaff established to facilitate data collection ( figure 1) also served
as a practical tool to optimise medical coverage for the teams.This was important, as the athletes involved spent most of thepreparatory period with their club, relying upon local/externalmedical support. The weekly reporting enhanced the Olympicmedical team’ s awareness of health problems among their ath-
letes, and in many cases this led to earlier and more comprehen-sive intervention. This is one potential explanation for thereduction in the prevalence of overuse and illness problemsthroughout the course of this study. However, it must be takeninto consideration that by improving athletes ’medical coverage,
the system inherently affects its own data.
A third modi fication is that, in addition to the average weekly
severity score, an additional measure of severity, the cumulativeseverity score, was calculated for each health problem. This pro-vides information on the relative impact each case has on theathlete, as it takes into account the degree of consequences andthe duration of the problem. Summing cumulative severity
scores also enables an estimation of the total burden of different
types of problems, or within different groups of athletes. Oneimportant finding in the current study was that overuse injuries
placed a much greater burden on the athletes than illnesses andacute injuries (49%, 36% and 13%, respectively , of the summedcumulative severity score), in contrast to what is typically foundusing standard surveillance methods.
791 52 6 –29
For acute injuries, we consider standard surveillance methods
to be a satisfactory alternative to the new method, as it wasarguably for this purpose that they were developed.
16 21
However, data collected by medical staff may not always becomplete and accurate,
30 31and systematic bias may be intro-
duced when broad de finitions are used.32As the methods used
in this study do not rely on medical staff as the means of deter-mining the occurrence of a case, a major source of systematicbias is eliminated. Therefore, the novel methodology may be apreferable alternative, particularly as recording all complaints isdesirable in many instances.
33It should be noted that dataTable 3 Location and degree of time loss for acute and overuse injuries
LocationAcute injuries Overuse injuries
Slight Minimal Mild Moderate Severe
TotalSlight Minimal Mild Moderate Severe
Total (0 days) (1 –3 days) (4– 7 days) (8– 28 days) (>28 days) (0 days) (1– 3 days) (4 –7 days) (8– 28 days) (>28 days)
Head 1 2 1 –– 4 – –––– –
Neck 1 –– – – 1 5 221 – 10
Shoulder – 11 1 – 32 2 3 1 – 43 0
Upper arm –– – – – – 1 –– 1 – 2
Elbow 1 – 1 –– 23 1 1 – 16
Forearm –– – – – – 3 – 1 –– 4
Wrist and hand 10 6 – 1 – 17 3 2 1 –– 6
Chest –– – – – – 11 ––– 2
Trunk and abdomen –– – – – – – 11 –– 2
Thoracic spine 1 –– – – 16 2 – 1 – 9
Lumbar spine –– – – 1 1 1 4 643 – 27
Pelvis and buttock –– – – – – 31 2 –– 6
Hip and groin 2 2 –– – 47 –– 1 – 8
Thigh 1 5 1 2 – 91 0 3 1 –– 14
Knee
2 – 1 – 1 4 1 9 9332 3 6
Lower leg – 1 – 1 – 2 3 231 – 9
Ankle 6 4 1 1 – 12 8 5 1 –– 14
Foot –– – – – – 5 712 – 15
Disabled –– – – – – – 2 ––– 2
Total 25 21 6 6 2 60 113 47 22 13 7 202
Table 4 Interitem and item –total correlations and effects of
removing items on internal consistency
Interitem correlation matrix
Item –total
correlationCronbach ’s
αif item
deletedQuestion
1Question2Question3
All questionnaires (n=4470)
Question 1 – 0.92 0.94
Question 2 0.87 – 0.90 0.94
Question 3 0.89 0.88 – 0.92 0.94
Question 4 0.85 0.80 0.84 0.87 0.95
Non-injury cases (n=3384)
Question 1 – 0.94 0.95
Question 2 0.91 – 0.91 0.96
Question 3 0.90 0.91 – 0.94 0.95
Question 4 0.87 0.82 0.88 0.88 0.96
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collected using the new method can also be presented according
to consensus guidelines,16as demonstrated in table 3.
Although illnesses are increasingly being included in surveil-
lance studies,6–81 01 12 63 4there is a wide variation in the way
in which they are recorded and reported. Similar to injuries,issues are likely to arise when recording illnesses using standardprospective methods, particularly as athletes with mild orchronic conditions are likely to continue to participate in sport.The methods used in this study may therefore be a good optionwhen these problems are of interest. Although OSTRCQuestionnaire was first developed for the study of injuries, our
analyses of its psychometric properties suggest that it may alsobe appropriate to monitor illness consequences.
It must be acknowledged that the success of this method of data
collection is entirely dependent on a good response from athletes,as well as a thorough follow-up from team medical staff to recorddiagnoses. In the current study , the average response rate of 80%was high, as was the percentage of cases successfully diagnosed(94%). However, this was a study of highly motivated elite athletes
in a well-organised Olympic team structure, and it is not yet
known how these methods will function in other settings.
Finally, as in our previous paper, we performed data simula-
tions of the effects of administering questionnaires every secondand fourth week, rather than weekly. The results indicate that,in future epidemiological studies using this method, it is possibleto sample less frequently as the primary outcome measures,average prevalence and severity are unchanged. However, thedata simulations highlight the fact that cumulative severityscores are not comparable between studies unless the studies areof the same duration and use the same sampling frequency.Also, as fewer problems are identi fied and the frequency of
reporting to the medical team is reduced, administering ques-tionnaires less frequently would comprise this method ’s value as
a practical health monitoring tool.
CONCLUSION
This paper presents a new approach to recording all types ofhealth problems in sport, showing that the method is sensitiveand valid in documenting the pattern of acute injuries, overuseinjuries and illnesses in a large, heterogeneous group of athletesduring a 40-week preparatory period before the Olympic andParalympic Games. Overuse injuries represented a much greaterburden (49%) on the athletes than illnesses (36%) and acuteinjuries (13%), in contrast to what is typically found usingstandard surveillance methods.
What are the new findings?
▸A new approach to monitor athletes ’health using regular
online questionnaires enables valid and reliable registration
of all types of problems, including illness, overuse injury andacute injury.
▸At any given time, more than one in three athletes preparingfor the Olympic or Paralympic Games had health problems.
▸Overuse injuries represented the greatest burden on athletes ’
health, in comparison to acute injuries and illnesses.
How might it impact on clinical practice in the near future?
This paper may lead to a change in the methods used insurveillance studies of athletes, particularly when overuseinjuries and illnesses are of interest.
Acknowledgements The authors acknowledge Olympiatoppen ’s support of this
project. We thank the athletes, physicians and physiotherapists involved in the
project for their assistance in data collection. The Oslo Sports Trauma Research
Center has been established at the Norwegian School of Sport Sciences through
generous grants from the Royal Norwegian Ministry of Culture, the South-EasternNorway Regional Health Authority, the International Olympic Committee, theNorwegian Olympic Committee & Confederation of Sport, and Norsk Tipping AS.
Contributors All authors were involved in planning the project, data collection
and preparing the manuscript. BMC was responsible for co-ordination of the data
collection and for data analysis. BMC is responsible for the overall content as the
guarantor.
Competing interests None.
Ethics approval Norwegian Data Inspectorate and South-Eastern Norway Regional
Committee for Research Ethics.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Unpublished data are available upon request.
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Average cumulative severity score 114 (96 –132) 83 (71 –95) 60 (51 –69)
Average duration of problems (weeks) 3 (3 –3) 2 (2 –2) 2 (1 –2)
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doi: 10.1136/bjsports-2012-09208721, 2013 2014 48: 754-760 originally published online February Br J Sports Med Benjamin Clarsen, Ola Rønsen, Grethe Myklebust, et al. illness and injury in elite athletesapproach to prospective monitoring ofquestionnaire on health problems: a new The Oslo Sports Trauma Research Center
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