Direct discharge of patients with simple stable musculoskeletal injuries as an alternative to routine follow-up: a systematic review of the current literature

Purpose There is growing evidence that patients with certain simple stable musculoskeletal injuries can be discharged directly from the Emergency Department (ED), without compromising patient outcome and experience. This study aims to review the literature on the effects of direct discharge (DD) of simple stable musculoskeletal injuries, regarding healthcare utilization, costs, patient outcome and experience. Methods A systematic review was performed in Medline, Embase, CINAHL, Cochrane Library and Web of Science using PRISMA guidelines. Comparative and non-comparative studies on DD of simple stable musculoskeletal injuries from the ED in an adult/paediatric/mixed population were included if reporting ≥ 1 of: (1) logistic outcomes: DD rate (proportion of patients discharged directly); number of follow-up appointments; DD return rate; (2) costs; (3) patient outcomes/experiences: functional outcome; treatment satisfaction; adverse outcomes; other. Results Twenty-six studies were included (92% conducted in the UK). Seven studies (27%) assessed functional outcome, nine (35%) treatment satisfaction, and ten (38%) adverse outcomes. A large proportion of studies defined DD eligibility criteria as injuries being minor/simple/stable, without further detail. ED DD rate was 26.7–59.5%. Mean number of follow-up appointments was 1.00–2.08 pre-DD, vs. 0.00–0.33 post-DD. Return rate was 0.0–19.4%. Costs per patient were reduced by €69–€210 (ranging from − 38.0 to − 96.6%) post-DD. Functional outcome and treatment satisfaction levels were ‘equal’ or ‘better’ (comparative studies), and ‘high’ (non-comparative studies), post-DD. Adverse outcomes were low and comparable. Conclusions This systematic review supports the idea that DD of simple stable musculoskeletal injuries from the ED provides an opportunity to reduce healthcare utilization and costs without compromising patient outcomes/experiences. To improve comparability and facilitate implementation/external validation of DD, future studies should provide detailed DD eligibility criteria, and use a standard set of outcomes. Systematic review registration number: 120779, date of first registration: 12/02/2019. Supplementary Information The online version contains supplementary material available at 10.1007/s00068-021-01784-z.


Rationale
Traditionally, all patients with musculoskeletal injuries are referred to a fracture clinic for further review and treatment, after initial assessment in an Emergency Department (ED). Consequently, fracture clinics are often characterized by the referral of large numbers of unselected patients, many of whom have minor injuries that do not require intervention. This leads to long waiting times, recurrent unnecessary reviews, and a high workload that inevitably has 1 3 consequences for patient experience, staff morale, training, and quality of care [1].
A Virtual Fracture Clinic (VFC) model has been introduced in several hospitals worldwide as an alternative model of fracture care to regulate access to fracture clinics [2,3]. This model is increasingly used in the United Kingdom (UK), but also in the Netherlands, Norway, Australia and New Zealand [3]. The VFC model comprises two main components [2].
First, direct discharge (DD) of patients with relatively simple stable musculoskeletal injuries. This means patients are discharged without subsequent review or repeated imaging, supported by self-removable orthoses, discharge leaflets, and a telephone helpline. Second, the establishment of an individualised management plan for all other patients during a daily consultant-led VFC review. This process should further streamline outpatient care and ensure that each patient is seen at the right time by the most appropriate person [2].
The DD protocols were developed based on studies showing that for several minor self-limiting injuries, casting offers no benefit over functional treatment [2], and on the assumption that patients with these injuries require reassurance and information, but do not need to attend a fracture clinic routinely. However, for DD to be a useful and acceptable alternative to routine follow-up, patient outcome, patient experience and complication rates should at least remain comparable, while healthcare utilizations and consequently costs are ideally reduced. Despite several independent studies that were conducted since DD was first established in 2011 [2], an overview of all current evidence regarding DD is not available.

Objectives
The objective of this study was to systematically review the literature on the logistic and financial benefits of DD of patients with simple stable musculoskeletal injuries, as well as their patient-reported outcome, experience, and adverse outcomes. To illustrate the possible treatment of a patient with a simple stable musculoskeletal injury, both before and after DD, two case samples are provided below.
Case example I-Torus/buckle fracture A 10-year-old boy presents to the Emergency Department (ED) complaining of wrist pain after a fall from his bicycle. The patient is examined by an ED physician or Orthopaedic consultant. Radiographic imaging of the wrist reveals a torus/buckle type fracture of the distal radius, without any angulation Treatment before implementation of direct discharge Treatment after implementation of direct discharge Case example I-Torus/buckle fracture A plaster cast/splint is applied in the ED A follow-up appointment is scheduled in the fracture clinic in 7 days After 7 days, the cast/splint is removed. Bandage and a sling are applied. Parents are instructed to remove the bandage in a few days as pain allows. No further imaging is performed The patient is then discharged from follow-up with instructions regarding sports, etc A removable wrist orthosis is applied in the ED Verbal instructions are provided in the ED with regard to the injury, recovery, when to remove the orthosis, when to contact the hospital, etc This is also summarized in a discharge leaflet and/or smartphone application No follow-up appointments are scheduled It is allowed to remove the orthosis e.g., to take a shower, and parents are instructed to permanently remove the orthosis after 7 days If pain does not allow, then the orthosis can be used for another week A special telephone helpline is available in case of any questions or concerns. If necessary, a face-to-face follow-up appointment is scheduled Case example II-Fifth metatarsal fracture A 50-year-old woman presents to the Emergency Department (ED) complaining of pain on the lateral side of her foot after missing the last step of the stairs. The patient is examined by an ED physician or Orthopaedic consultant. Radiographic imaging of the foot reveals a non-displaced fracture of the base of the fifth metatarsal bone (i.e., Zone 1/Dancer's fracture) Treatment before implementation of direct discharge Treatment after implementation of direct discharge A plaster cast/splint is applied in the ED A follow-up appointment is scheduled in the fracture clinic in 7 days After 7 days, the cast/splint is removed and a new splint is applied. The patient is scheduled for another appointment in 5 weeks After 5 weeks, the splint is removed and radiographic imaging is performed. The radiograph shows first signs of bone healing Based on local protocols and physician preference/examination, the patient is then either; discharged from further followup with instructions regarding sports, etc reviewed again in a few weeks to assess functional outcome and perform radiographic imaging A removable orthosis (walker boot) is applied in the ED Verbal instructions are provided in the ED with regard to the injury, recovery, when to remove the walker, when to contact the hospital etc This is also summarized in a discharge leaflet and/or smartphone application No follow-up appointments are scheduled It is allowed to remove the orthosis e.g., to take a shower, patients are instructed to use the walker for 6 weeks and wear a supportive shoe A special telephone helpline is available in case of any questions or concerns. If necessary, a face-to-face follow-up appointment is scheduled, and/ or imaging is performed

Protocol and registration
This systematic review was planned, conducted, and reported using PRISMA guidelines [4]. A study protocol was registered with the PROSPERO register prior its commencement (registration number: 120779) [5].

Eligibility criteria
Both comparative (i.e., routine care before DD protocols were adopted compared to DD) and non-comparative studies (i.e., a DD cohort only) were considered if they featured DD of one or more musculoskeletal injuries in an adult, paediatric, or mixed population. Case reports and abstracts were excluded. There were no restrictions regarding the timing of the study, nor the duration of follow-up. Only articles reported in English were included. Direct discharge was defined as scheduling no routine follow-up appointment after the ED visit. This could either take place directly after the ED visit (ED DD) or after a daily 'virtual' review (VFC DD, Fig. 1). A single fracture clinic visit, shortly after attending the ED, was interpreted as ED DD if the sole purpose of this visit was application of a removable splint/orthosis. Studies were excluded if any further information or assessments were part of this visit. Studies were also excluded if reporting the potential effects of DD, without actually discharging patients directly. Both prospective and retrospective studies were included if reporting one of the following outcomes:

Logistic outcomes
Logistic outcomes included: (1) proportion of patients discharged directly, (2) number of follow-up appointments, and (3) number of repeat radiographs during follow-up. If the number of follow-up appointments was not reported, a study was also included if it reported a return rate instead (i.e., the proportion of patients that returned to the hospital despite being discharged directly).

Financial outcomes
Financial outcomes included any report on costs, for instance healthcare costs, societal costs etc.

Patient outcomes
Patient outcomes included any patient-reported experience/ outcome measures (PREMs/PROMs) and adverse outcomes.

Information sources
Medline, Embase, CINAHL, Cochrane Library and Web of Science databases were searched from inception to 15 January 2020. A limited update literature search was performed on 6 August 2020. Reference lists of included studies were scanned to ensure literature saturation.

Search
The electronic search strategy was developed by a health librarian and peer-reviewed by another librarian. Medical subject headings (MeSH) were used in Medline and complemented by text words related to DD and (virtual) fracture clinic redesign. This search strategy was then translated for the other databases. The PICO strategy and the full electronic search of Medline are reported in Tables S1 and  Table S2, respectively.

Study selection
Two review authors (THG and JV) independently screened the titles and abstracts yielded by the search against the inclusion criteria. Full texts were obtained if studies appeared to meet the inclusion criteria, or in case of uncertainty. All reasons for exclusion were recorded. Reviewing authors were not blinded to the journal titles, study authors and institutions.

Data collection process
A data extraction sheet was developed and pilot-tested on five randomly selected included studies, and refined accordingly. Data from the included studies were extracted by one author (THG) and checked by another (JV).

Data items
The following data items were collected for all included studies: country; year; design; sample size; injury/injuries studied; eligibility criteria for DD; population (adult/paediatric); study period. If reported, the distribution of patients across the various parts of the VFC model (i.e., ED DD; VFC DD or VFC follow-up, Fig. 1) was extracted and summarized in Table S3. Information on the type of immobilization used before and after DD protocols were implemented was extracted and summarized in Table S4.
The following data items were extracted if available: the proportion of patients discharged directly; number of followup appointments; return rate; number of repeat radiographs; costs; functional outcome score; any other PROMs or PREMs measured; any adverse outcomes reported. Method of assessment, timing and response rate (if applicable) were collected for all outcomes of interest. Missing information was scored as 'not reported'. Authors were contacted if further information or confirmation of data was required.
In some studies, only part of the intervention cohort consisted of patients who were discharged directly (e.g., if the effects of the whole VFC model as a whole was assessed, rather than the effect of DD in particular; Fig. 1). For those studies, if possible, we extracted logistic outcome and adverse outcome data only for the patients who were discharged directly (DD cohort). If this was not possible, data were only extracted if > 75% of patients within the intervention cohort were discharged directly. Costs and PREMs/PROMs data were extracted and only included in the main analysis if reported specifically for patients discharged directly (DD cohort).

Risk of bias in individual studies
Two reviewers (THG and JV) independently assessed risk of bias using the Cochrane risk-of-bias tool for randomized controlled trials [6], and the Newcastle-Ottawa Quality Assessment Scale (NOS) for non-randomized studies [7]. A modified NOS was used to assess non-comparative studies. Following the manuals of the tools, studies were scored as either having a "low", "medium", "high" or "unclear" risk of bias.
Disagreements regarding study selection, data collection or risk-of-bias assessment were resolved through discussion or by consulting a third author (JCG).

Summary measures
To summarize the results, various outcome-specific summary measures were estimated based on the extracted data, including: (1) logistic outcomes: DD rate (proportion of patients discharged directly); mean number of follow-up appointments, and in case of a comparative study the mean reduction; mean repeat radiographs, (2) financial outcomes: costs as reported, and in case of a comparative study, the absolute and proportion difference in euro (€) and %, respectively, (3) patient outcomes: functional outcome score using a validated multi-item questionnaire; satisfaction with treatment; number and rate of adverse outcomes divided in nonunion, secondary surgery, and other.

Synthesis of results
We chose not to pool data via meta-analysis due to high levels of clinical and methodological heterogeneity. For all outcomes, findings were, therefore, presented narratively and in summary tables.

Study selection
The search identified 5872 unique records, 5668 of which were excluded after screening title and abstract. A further 184 studies were excluded after reading full texts. Six additional studies were included after scanning reference/citation lists and an updated search. Figure 2 shows the selection process and an overview of the reasons for exclusion.
Two studies were based on the same cohort [2,8]. In both studies, the only outcome relevant for this systematic review was the DD rate. Therefore, we did not exclude one as duplicate, but merged the results of these studies in the corresponding table. Another study described results for three types of injuries separately [9]. Therefore, the results of this study were summarized per injury separately in all tables.

Risk of bias within studies
Risk of bias was "low" in fifteen studies, "high" in four studies and "unclear" in the remaining seven studies (Table S5).

Logistic outcomes
In 10 studies, the intervention cohort consisted exclusively of patients discharged directly. Hence, a DD rate could not be estimated. In the remaining 16 studies, the DD rate ranged from 18.2 to 97.9% (Table 2). Of these 16 studies, three reported a DD rate as a proportion of all patients that attended the ED with a musculoskeletal injury. The DD rate in these studies was 26.7%, 59.5% and 33.3%, respectively [1,8,30].
The mean number of follow-up appointments was reported in eleven studies, and ranged from 1.00 to 2.08 in the control cohort vs. 0.0-0.33 after implementing DD (Table 3). In the comparative studies, the mean reduction of follow-up appointments ranged from 1.00 to 1.78 appointments per patient.
Twelve studies determined a return rate of patients after DD. Brooksbank et al. found 19.7% of patients that sustained a mallet finger injury to return after DD [21]. All other studies reported a return rate of less than 10%.
The mean number of repeat radiographs was reported in five studies [9,10,17,22,24,25]. Of the two comparative studies, Mackenzie et al. reported a mean reduction of 0.34, 0.17 and 0.79 radiographs per patient, in patients with fifth metacarpal neck, fifth metatarsal and radial head fractures, respectively [9]. Seewoonarain et al. found a mean reduction of 1.00 radiograph per patient with a torus wrist fracture [17]. In three non-comparative studies, the mean number of repeat radiographs in the DD cohort was 0.0 based on a return rate of 0% [22,24,25].

Patient outcomes
Seven studies assessed functional outcome using a validated questionnaire, including four non-comparative and three comparative studies ( Table 5). The three comparative studies found equal functional outcome scores before and after implementing DD [9,11,13]. Of them, Mackenzie et al. reported significantly better QuickDASH scores at 6 months within the DD subgroup of patients with fifth metacarpal fractures [9]. All four non-comparative studies reported good recovery in terms of functional outcome based on QuickDASH scores within the DD cohort.
Satisfaction with treatment was reported by nine studies, five of which were comparative and four were noncomparative (Table 6) [11]. Three studies reported no difference in satisfaction before and after implementing DD, without providing any rates [13,15,16]. Mackenzie et al. found high satisfaction rates before and after implementing DD (95% vs. 98% using a yes/ no "are you satisfied with treatment" question) [9]. The four non-comparative studies all assessed satisfaction rates based on a Likert satisfaction scale, and satisfaction ranged from 84.9 to 100% [21,24,25,29]. All other PROMs and PREMs that were reported in the individual studies are summarized in Table S6. These included, amongst others, satisfaction with recovery and whether patients had visited other clinicians such as their general practitioner for the treatment of their injury.

Summary of evidence
This systematic review supports the idea that patients with certain simple and stable injuries can be discharged directly from the ED without compromising patient outcome. This suggests that DD offers an opportunity to alleviate fracture clinic workload by reducing unnecessary appointments and consequently healthcare costs. This will allow physicians to spend more time on patients with more complex injuries, teaching, training, or improving standards of care. Frequently, studies, including several systematic reviews performed recently [32][33][34], report on the effects of the VFC model as a whole. This model includes both DD of simple stable musculoskeletal injuries, as well as a daily VFC review, consequently including more complex injuries that require follow-up (Fig. 1) [1, 2, 8, 33]. This limits the ability to independently assess the feasibility, efficacy and safety of DD of simple stable musculoskeletal injuries as a solitary concept. To our knowledge, this is the first systematic review to focus exclusively on DD of simple stable musculoskeletal injuries. Herewith, it provides an extensive and critical evaluation of all evidence currently available.

Logistic outcomes
The DD rate as a proportion of all patients in the ED with a musculoskeletal injury ranged from 18 to 59.5% [1,2,8,14,30]. This is a remarkably large variation, and despite the studies' lack of detail on their DD eligibility criteria, this variation is most likely caused by a combination of: (1) differences in the definition of 'all musculoskeletal injuries' (i.e., including contusions, wounds, soft-tissue injuries, or not), (2) differences in the kinds of injuries discharged directly, and (3) differences in the period since the DD protocols were first implemented [31]. Regardless of this variation, when implemented, DD will concern a large number of patients with musculoskeletal injuries that are seen frequently in an ED. This is an important factor to determine the logistic level of impact on a fracture clinic. Among the included comparative studies in this systematic review, the mean reduction in the number of follow-up appointments after DD ranged from 1.00 to 1.78 after DD.

Financial outcomes
All studies that estimated financial effects found DD to reduce healthcare costs. However, cost-analyses were limited to relatively simple estimations of fracture clinic costs, such as material costs, radiology costs and staffing costs. Hence, other important cost categories, such as other healthcare costs, (unpaid) productivity costs, and possibly informal care costs were not included. While it seems evident that healthcare costs reduce when healthcare utilization reduces, these results should be interpreted in a national context, as different healthcare payment systems are in place in each country. Furthermore, full economic evaluations, preferably from a broader healthcare perspective or a societal perspective, are needed to estimate the cost-effectiveness of DD compared with usual practice.

Patient outcomes
All comparative studies reported 'as good' or 'better' functional outcome and satisfaction with treatment in the DD cohort compared to patients treated before DD protocols were implemented. The non-comparative studies also reported high levels of satisfaction and satisfactory functional outcome. Of the included studies, Bhattacharyya et al. reported a relatively high mean QuickDASH after DD of patients with a clavicle fracture [18], but this is within the range of the normative values of this questionnaire [35]. Non-union and secondary surgery rate were reported in fifth metatarsal fractures [9,12,20], fifth metacarpal fractures [9], radial head fractures [9,28], and clavicle fractures [18]. These rates were low and comparable in all cohorts. The DD model is established around the idea that a large proportion of patients are well able to manage their recovery independently, if adequately instructed. This model also appreciates that some patients will have concerns or persisting pain, and an even smaller number might develop complications like non-union. However, these problems would have probably also occurred despite routine follow-up, and the majority of patients recover without any issues. Follow-up should, therefore, not solely serve as a safety net to identify those patients with concerns, or complications that might occur in 1-2%. Rather, our results emphasize the importance of instructing patients when to contact the hospital, and of providing an open access helpline in case of any concerns. This helpline should always be part of the DD model, with subsequent face-to-face review in a fracture clinic if necessary.

Limitations
This review should be regarded in light of the following limitations. First and foremost, there was high clinical and methodological heterogeneity amongst the included studies. As a consequence, we were not able to perform a meta-analysis. Second, most studies were non-randomized and are therefore prone to selection bias, especially in retrospective cohort studies. Randomization at an individual patient level might not always be feasible for treatment redesigns like DD. However, other methods to reduce confounding effects of systematic differences in baseline characteristics were not used, including institutional cluster-randomization, or advanced statistical techniques such as a propensity score matching or weighting.
Third, only seven studies (27%) assessed functional outcome within the DD cohort using a validated questionnaire, only nine studies (35%) assessed patient satisfaction with treatment and only ten studies (38%) assessed adverse outcomes. Moreover, there was a large variety of other patientreported outcomes/experiences measured, with methodology of assessment ranging from use of Likert scales, simple yes/no questions, and 1-10 rating scales. Furthermore,  [20] 5MT Fx EPR and PACS > 6 m 1 (0.15), symptomatic non-union Jayaram [28] Radial head/neck Fx NR > 6 m 1 (0.5) in DD cohort, malunion Mason II fracture Other Breathnach [19] Multiple NR 18-24 m 1 (0.64) poor clinical outcome, referred to physiotherapist Callender [22] Torus Fx wrist NR NR 'No adverse events or clinically significant complications' Evans [23] Hand/wrist injuries Survey NR 'No complications of treatment' Ibrahim [27] Hand injuries Hand therapist NR 'No adverse outcomes' Robinson [31] Multiple EPR review > 1 m 'No serious adverse outcomes' with regard to logistic outcomes, the extent to which the included studies assessed whether patients visited their GP or another hospital/clinician for further treatment was limited (Appendix Table S6). However, only non-comparative studies assessed this, while comparative studies would be needed to indicate whether DD increases GP visits or visits to another hospital/clinician. Fourth, several studies have reported high numbers of patients discharged directly, but this far exceeds the number of patients in which logistic, financial and patient outcomes have actually been evaluated. To illustrate, Glasgow Royal Infirmary have discharged 3802 patients in the first year alone [2], while a later study reported that 30,000 patients were treated successfully since the implementation of their VFC pathway, 65% of which were discharged directly [36]. White et al. studied a cohort of 12,069 patients, 3222 of which were discharged directly [1]. Despite these figures, this systematic review included 'only' 2137 patients in the DD cohort to assess logistic outcomes, with even smaller sample sizes for patient outcomes. In other words, there appears to be a gap between clinical practice and evidence base. Additionally, in 62% of the included studies, a clear description of the eligibility criteria for DD was not included and often limited to 'simple', 'minor' or 'stable' injuries. Altogether, this complicates implementation and external validation of DD in other hospitals.
Fifth, most studies were conducted in the UK; hence, the generalizability to other countries might be limited depending on the similarity of their healthcare system with that of the UK, e.g., whether extensive low-threshold public healthcare is available. Different baseline levels of effectiveness of care prior to DD, based on local protocols, might cause logistic outcomes to be different, and patient' mindset might result in different patient experiences or outcome, as well as patient's acceptance of DD without further care.
Last, most studies did not report a priori sample size calculations based on the minimal clinical important difference of a predefined primary outcome, such as satisfaction or function. Despite the significant reductions in appointments, sample sizes were often relatively small and, therefore, lacked statistical power to determine a change in patient experience, outcome or complications.

Future implications
Future studies on DD should be prospective, comparative and include subgroup analysis of each injury eligible for DD. We propose the minimum set of outcome variables of such studies to include: mean number of follow-up appointments, whether patients visited their GP or other hospital, functional outcome using a validated questionnaire, satisfaction using visual analogue scales as well as Likert point scales, and non-union/secondary surgery rates after at least 1 year. Furthermore, future studies should also focus on finetuning the DD treatment protocols by assessment of outcomes within specific patient sub-groups (i.e., based on age, comorbidity, injury subgroup, etc.). If such analyses indicate that specific patient characteristics are predictive of, for example, high levels of return for follow-up, dissatisfaction or low functional outcome, treatment protocols should be adjusted accordingly. Preferably, a multicentre database is be established to this end, as it is likely necessary to have a relatively large sample size in order to have sufficient power to conduct such subgroup analyses.
Based on the high remodelling capacity and low rate of non-union in children [37], it is highly likely that DD is also a safe alternative for several stable paediatric injuries. However, Robinson et al. were the only authors to report on DD of paediatric injuries, other than paediatric clavicle and torus wrist fracture, exclusively within a paediatric cohort [31]. Future studies could focus on the identification of additional minor and stable injuries that can be discharged directly, both in the adult and paediatric population.

Conclusions
Despite the clinical and methodological heterogeneity of the included studies in this systematic review, DD of several simple and stable injuries seems to be an effective alternative to routine follow-up, which does not seem to compromise patient outcome. Future studies on DD of those as well as other injuries should use a standard set of baseline and outcome variables to improve comparability and facilitate implementation and testing of external validity in other hospitals, especially in countries other than the UK with different healthcare systems.
Data availability All data are available upon reasonable request.
Code availability Not applicable.

Declarations
Conflict of interest All authors have completed the ICMJE uniform disclosure form at www. icmje. org/ coi_ discl osure. pdf and declare: apart from the unrestricted grant, the authors have nothing to declare; no financial relationships with any organizations that might have an interest in the submitted work in the previous 3 years; no other relationships or activities that could appear to have influenced the submitted work.
Ethics approval Not applicable.

Consent for publication Not applicable.
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