The present study is based on a well-defined study and reference population identified by register data that cover the total adult population. The national health registers include data about hospital contacts and use of primary healthcare services.17
Contacts with private hospitals may not be included in the national patient register; however, these contacts only contribute less than 3% of the total number of outpatient contacts and 1% of all admissions.18
All data about health service use are registered using the unique person number that made it possible to obtain information about health service use in the study and control groups during the follow-up period.
Patients with the three studied types of injury had an increased use of health services compared to a matched reference group during the follow-up period. However, the amount, duration and type of health service use differed between the types of injury. Patients with SCI had the highest use of health services, about three times more admissions and six times more physiotherapy use compared to the controls. The level of use remained that high 9 years after the injury year. For patients with TBI the number of hospital admissions was increased most of the 9 years after the injury year, while outpatient treatments and the use of GP services approached the baseline level year 4 after the injury year. For patients with PF the health service use approached baseline level year 2 after the injury year; although not significant, the use of physiotherapy among patients with PF was above baseline level 5 years after the injury year.
Our results concern the age-group of 20-year-olds to 64-year-olds, whereas several previous studies of health service use after severe traumatic injuries include either older or younger age-groups, hence, results are not directly comparable. A Canadian study of SCI included patients 70 years old and above, and reported a higher contact rate to physicians 1 year after the injury year than did our study,11
and a study by Becker et al10
of PF patients based on US Medicare data and thus including mainly older patients reported a higher use of GP services 6 months postinjury than our study. However, the frequency of hospital admission among patients with SCI in our study is comparable to a Canadian study that followed 223 SCI patients 6 years postinjury.5
A US study of healthcare use among paediatric patients with TBI reported about the same level of physiotherapy use as we observed among 20-year-olds to 64-year-olds in our study but found a lower rate of GP contacts.19
In accordance with our results few studies report long lasting increase in the use of health services after PF.20
The level of healthcare use may depend on the healthcare system. In Denmark most treatments are free of charge or only partly paid by the patient. Further, different services are included. For example, physiotherapy may include both individual treatments and training in a group. This may be part of the explanation to the relatively frequent use of, for example, physiotherapy.
There are, however, some limitations to the present study. The case identification is based on the National Hospital Register and, thus, depends on the validity of this register. In general, the data in the National Hospital Register are found to be valid, however depending on diagnosis; about 79% of the injury diagnoses were correct.17
In the present study, we included diagnoses that were not specific, like S32.8, fracture of other and unspecified parts of lumbar spine and pelvis. This limited the possibility to study more specific injury groups. Because the study is based on administrative data reporting of services may change during the period, the numbers should be interpreted with care. In some cases a few persons uses a relatively large part of the services.
Patients treated during 1996 for other injuries with lifelong consequences according to Haagsma et al15
were excluded from the study. This may result in underestimation of the effect of the injury.
In order to solely include incident cases in 1996, we excluded cases registered with the same or similar diagnoses during 1978–1995. However, some of the patients treated in 1996 may have been injured before 1978 and not treated during the period 1978–1995. This may result in a larger health service use in the patient group at baseline. Due to the matching by health service use there may also be a larger health service use in the control group.