As noted by others and in the previous section, earlier as opposed to delayed admission to interdisciplinary, specialized SCI units has been associated with a variety of beneficial outcomes (DeVivo et al., 1990). The question of whether earlier admission to an organized system leads to enhanced outcomes is inexorably linked to the question of specialist vs general care for individuals with SCI. In all studies in this and the preceding section the authors framed their studies as addressing either the question of delay or the question of interdisciplinary, specialist care yet similar designs were employed for each (i.e., retrospective case control). For those subjects experiencing a delay to admission to a specialized SCI unit, it was either presumed or established that preceding acute care was conducted at a general hospital unit. The author simply chose to characterize this as either a delay or more general care. For the present review we have maintained this distinction as originally intended by each author, especially, as in some cases, there is little or no verification of the general nature of the pre-admission care or the time of first admission, respectively. However, the reader is advised that the specific findings and conclusions reached in both sections are most likely associated with a delay to an interdisciplinary, specialized acute or rehabilitation SCI unit with prior care delivered at a general hospital facility.
In addition, much variation exists in the literature that addresses the question of delayed admission. There is no uniform or accepted definition of what constitutes a delay and this varies depending on the context of the study, most notably whether it is conducted from an acute vs rehabilitation perspective. For the present review, all studies which examine this question by comparing 2 or more groups within the first week post-injury have been examined separately from those with an initial time period greater than 1 week post-injury. These have been termed 1) Acute and 2) Post-acute studies, respectively.
The present section describes a series of studies in which investigators examined the effect of delayed admission to a specialist SCI unit. However, there is not a common definition of what constitutes a “delayed” admission. Therefore, to assist the reader in summarizing these delays, the details of the various time frames under examination are outlined along with their respective results in Table 13.
Two acute studies were reviewed which each employed retrospective, 2 group (case control) designs with a definition of 24 hours as to what constituted an “early” vs a “delayed” admission (DeVivo et al. 1990; Dalyan et al. 1998). Each study examined a fairly large cohort admitted to a multidisciplinary, specialized SCI unit (i.e., US model system center) within 24 hours post-injury vs those admitted after 24 hours. Neither study reported the actual injury to admission times for the “delayed” admission group and both failed to provide information about the referral sources (e.g., specialist vs. general nature). DeVivo et al. (1990) noted that total hospital LOS (i.e., acute and rehabilitation) was reduced for all patient groups except for those with complete tetraplegia when admission was not delayed. Mean hospital charges were also reduced for early admission subjects except those with complete paraplegia and there were some reductions in the incidence of specific medical complications with early admission for some patient groups, most notably a trend for a reduction in pressure sores for all but those with incomplete paraplegia. In addition these authors also reported a trend for increased neurologic recovery and reduced mortality with earlier admission, although they also noted methodological concerns associated with the actual measures employed. Dalyan et al. (1998), in a study focusing on the development of contractures, noted a reduced incidence of contractures for those admitted within 24 hours to a specialized unit.
Of the studies examining time periods longer than one week (i.e., post-acute), five studies have been reviewed (Oakes et al. 1990; Aung & el Masry 1997; Sumida et al. 2001; Amin et al. 2005; Scivoletto et al. 2005). The initial admission delays examined ranged from 1 week (Aung & el Masry 1997) to 1 month (Scivoletto et al. 2005). All studies employed retrospective case control designs and all examined LOS for the entire period of initial hospitalization as a primary outcome measure. In all cases, those admitted earlier had reduced LOS, regardless of the considerable variation between studies in the definition of what constituted a delay in admission. It should be noted that this difference to LOS was statistically significant for all studies but one; for which it was reported as a trend (p=0.15). This study examined the longest delay of 1 month (Scivoletto et al. 2005).
Functional benefits were also demonstrated for individuals admitted earlier. Scivoletto et al. (2005) reported that those admitted earlier than 1 month had significantly greater gains and greater efficiency associated with the Barthel Index (BI) as well as greater mobility gains and efficiency as measured by the Rivermead Mobility Index (RMI) but there was no difference with respect to walking as measured by the Walking Index for SCI (WISCI). Similarly, Sumida et al. (2001) reported increased Functional Independence Measure (FIM) gains and efficiencies for those admitted earlier than 2 weeks post-injury as compared to those admitted later. Interestingly, these investigators also showed that for a majority of the various patient groups tested (i.e., paraplegia and tetraplegia, early and late), significant associations were seen between a measure of function (i.e., FIM) and a measure of impairment (i.e., ASIA motor scores). However, Scivoletto et al. (2005) found no effect of early vs. late admission on AIS motor scores. A follow-up study conducted by Scivoletto et al. (2006) reported significant improvements in all measures employed in their prior study (i.e., BI, RMI, WISCI, ASIA motor scores) as assessed between admission to discharge even in those subjects that were admitted at ≥90 days post-injury – although there was no control condition reported to confirm that these improvements were different than might have been seen with earlier admission. Taken together, these studies suggest better outcomes are seen with earlier admission, although improvements are still possible even if rehabilitation onset is delayed for several months.
Other investigators examined the role of early vs late admission on the incidence of secondary medical complications. Oakes et al. (1990) reported that earlier admissions were associated with a reduced incidence of secondary medical complications in those with tetraplegia and Aung and el Masry (1997) noted a reduction in the number of pressure sores for all subjects with earlier admission.
Despite the apparent benefits of earlier admission to a multidisciplinary, specialized integrated SCI unit, there are significant issues which serve to constrain the strength of evidence in this area. First and foremost is the retrospective nature of all studies conducted to date. It is difficult to ascertain how comparable the “early” vs “later” groups truly are with respect to potential confounding variables. In particular, there is a paucity of information on the pre-admission level of care and medical status, especially for the delayed admission groups. In addition, it is difficult to discern the potential role that medical status or the presence of secondary medical complications may have played in admission delays. The retrospective nature of the studies outlined in this and the previous section makes it difficult to determine if individuals prone to complications and with poorer medical status would have naturally comprised a greater proportion of the delayed admission groups. Therefore, as noted earlier, more carefully controlled prospective studies would be required to strengthen the evidence in this area.
Based on several retrospective, case-control studies there is level 3 evidence that individuals admitted earlier to interdisciplinary, integrated specialist SCI units have a shorter total hospitalization length of stay than those admitted later.
There is level 3 evidence that individuals admitted earlier to interdisciplinary, integrated specialist SCI units make greater functional gains in a shorter period of time (i.e., greater efficiency) than those admitted later.
There is level 3 evidence that individuals admitted earlier to interdisciplinary, integrated specialist SCI units have fewer secondary medical complications (especially pressure sores) than those admitted later.
There is level 4 evidence for positive utility of admission to rehabilitation even at delays ≥90 days post injury.
Because of the variability between studies as to what constitutes “early” admission to interdisciplinary, specialist integrated SCI units, it is not possible to determine a specific period for optimal admission. At least one study has demonstrated benefits with an early admission described as ≤30 days post-injury. The majority of studies defined early admissions as 1-2 weeks post-injury, while studies focused on acute care describe early admission as within 24 hours post-injury.