Research has repeatedly shown that people living with diabetes are at increased risk of being admitted to hospital and to stay in hospital longer than those who do not have the condition (1–6). These studies associate diabetes-related complications such as cardiovascular disease, hypoglycaemia, hyperglycaemia, hypertension, and renal insufficiency with an increased risk of prolonged hospitalisation in addition to health risk factors including age, obesity and sedentary lifestyles.

Approximately 422 million adults are currently living with diabetes mellitus worldwide, with occurrence increasing among all ages strongly associated with increasing trends in obesity, unhealthy diets, physical inactivity and socioeconomic disadvantage (7). Diabetes and its complications cause substantial economic loss to those living with the condition and their families, to health systems and national economies through direct medical costs and loss of work and wages (8). It is estimated that the number of people living with diabetes globally will increase to 642million by 2040 and that even if countries meet internationally set targets, the global economic burden from the condition will still increase by 88% (9). In 2019, total, world-wide diabetes-related health expenditure was estimated to be USD 760 billion in adults aged 20–79 years, with much of the spending among those aged 50–79 years (10). Diabetes accounts for up to £14billion of the NHS England and Wales healthcare budget (11) and up to 14% of the Irish health budget (12). In the United States, more resources were estimated to be spent on diabetes than any other condition with people diagnosed with diabetes, on average, having medical expenditures ∼2.3 times higher than expenditures in the absence of diabetes (13). With the global costs of diabetes set to almost double to USD 2.5trillion by 2030 this condition can be considered a global health threat (9).

Length of stay is a major factor driving up hospitalisation costs relating to those with Type 1 and Type 2 diabetes (14). Suboptimal blood glucose management, hypoglycaemia, hyperglycaemia and co-morbidities have been shown to significantly impact upon length of stay and mortality rates (14). Extremes in blood glucose can occur in hospital due to disrupted self-management patterns, nil-by-mouth requirements, delayed mealtimes, inappropriate timing of medications and when the body is under stress (15). Numerous obstacles challenge the achievement of glycaemic control and there is a need to better understand the factors that influence blood glucose regulation within hospital care (16). The National Diabetes Inpatient Audit England (17) highlights that the rates of life-threatening harms such as severe hypoglycaemic episodes in inpatients with Type 1 diabetes, hospital-acquired diabetic ketoacidosis (DKA) and hospital-acquired hyperosmolar hyperglycaemic states remain unchanged despite being preventable. While much has been reported on practices that can impact hospital outcomes and subsequently length of stay, more evidence is needed to indicate how the situation can be improved.

The provision of inpatient diabetes care includes diabetes self-management, promptly responding to DKA and other acute complications and preparing patients for clinical procedures and eventual hospital discharge facilitated by a proactive and knowledgeable workforce (18, 19). Clinical staff are working within current guidelines and hospital protocols, which outline treatment pathways for much of the decision making around monitoring and acting upon blood glucose levels that are out of target range. They take steps to reverse hypoglycaemia, the administration of oral and injectable therapies and liaise with, and make referrals to, other members of the clinical team throughout the patient’s hospitalisation. These approaches cannot be working optimally if length of stay is longer for those living with diabetes (1–6)The application of attainable evidence-based clinical practice strategies is necessary to inform the knowledge base and enable competent decision-making within an innovative clinical environment to enact appropriate care in practice.

Despite current protocols and guidelines, the extended length of stay for those with diabetes remains a serious problem, indicating the need for further evidence about what works in practice and offering opportunities to close the gaps between evidence and practice in diabetes care (20–25). This review aims to explore the efficacy of clinical practice strategies (such as the organisation of care, the inclusion of specialist practitioners in the team, the use of protocols or guidelines and technology) in improving clinical outcomes and reducing length of stay for inpatients with Type 1 and Type diabetes.

A review of the literature was undertaken using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines (26). This review is registered with the International Prospective Register of Systematic Reviews (CRD42020204825) (27).

Eighteen studies were identified across 9 countries: UK n= 8 (30–37); USA n= 6 (32, 38–42); Israel n= 2 (43, 44); Canada n=2 (32, 45); Taiwan n=1 (46); China n=1 (47); Spain n=1 (32); Italy n=1 (32); and Ireland n=1 (32). The studies varied in terms of design; two randomised controlled trials (32, 46); six intervention studies (28, 29, 31–33, 38); eight retrospective, prospective audit studies (30, 31, 33, 41, 43–45, 47) and three service improvement studies (34, 37, 42). Whilst we recognise that service improvement and audits are not research, important information can be garnered from these studies where statistically controlled outcomes have been presented. All studies included adults living with diabetes that were ≥18 years old.

Investigations included adult patients (≥18 years) with Type 1 diabetes (n=17) (31–47) and Type 2 diabetes (n=15) (30, 33–38, 40–47). Inclusion criteria consisted of adults with a diagnosis of diabetes ≥18yrs, presenting to intensive care unit (ICU) (39, 43, 44), having a hospital stay of more than 48 hours (41), with diabetic foot ulcer, gangrene, cellulitis or infection as the primary cause of admission (31, 46), cardiovascular disease (47), diabetes ketoacidosis (38, 40, 45), hyperglycaemia (35), receiving insulin therapy (32, 42) and undergoing elective surgery (44). Research ethics approval and/or patient consent was obtained (32, 38, 39, 43, 45–47) with remaining studies regarded as audits, service, and quality improvement (30, 31, 33–36, 40–42, 44). Six studies (32, 34, 38, 43, 46, 47) used control groups and two studies (42, 45) described pre and post implementation groups. Clinical outcomes and length of hospital stay were comparably improved in studies using control groups compared with studies that did not include a control group. Four themes were identified: Clinical Management Innovations, Clinical Education Programmes, Multidisciplinary Collaborative Care and Technology Facilitated Monitoring. They are represented below for differentiation and readability purposes.

Methodological assessments were completed by two reviewers [redacted] with the Critical Appraisal Skills Programme (CASP) (48) used to assess the methodological bias of eighteen studies and provide the criterion for evaluating these papers. CASP (2019) (48) checklists were used in the appraisal of the studies to examine the research design, validity of the results, outcomes considered, recruitment acceptability and equality and studies providing sufficiently robust evidence that demonstrates improved clinical outcomes and reduced length of stay and where such evidence could be translated into clinical practice. The checklists identified that the studies included in this review had clear aims and results, met the desired eligibility criteria with low level of risk (see Table 1 Intervention studies with improved clinical outcomes and reduced length of hospital stay). Limitations are most notable in the retrospective designs (30, 31, 33, 36, 41, 43–45, 47) small sample sizes (35, 36, 38–40, 42, 45) and single centre studies (30, 36, 38–40, 42, 44, 47) with novelty bias (31, 34, 36) and unequal allocation to groups (31, 34, 43). Three studies (34, 37, 42) utilised a quality, service improvement approach and although not research, we considered the outcomes to be significant for inclusion in this review. Fourteen studies presented statistically significant outcomes (30–33, 36, 38–40, 42–47), demonstrated adequately powered sample size (32, 39, 46) and made use of secondary data (30, 32, 35, 36, 40). Six studies were funded through non-commercial means (30, 32, 34, 36, 37, 47). This study does not indicate whether hospitalisations are diabetes related or non-diabetes related but examines conditions collectively as they relate to inpatient care. Strengths of the study include a comprehensive search of the major databases to identify all published empirical studies conducted on the topic. Furthermore, analyses of clinical interventions spanned a variety of practices that are already embedded in routine clinical care and/or require little change to implement.

The findings in this review demonstrate significant improvements in clinical outcomes and in length of hospital stay across attainable clinical practice strategies. Multidisciplinary collaborative care exhibited the most impact with significant reductions in length of hospital stay utilising a podiatric foot coordinator position (31) and a foot ulcer treatment programme (46), revealing decreased length of stay by 10.4 days (31) and 6.4 days (46) respectively. A diabetes consultation with specialised diabetes teams within the first 48hrs was also effective with a decreased probability of readmission and reduced length of stay by 1.56 days (41). Clinical management innovations such as the introduction of a nurse-led implementation of an intravenous insulin protocol showed a significantly reduced length of stay (4.9 days) in addition to improved target glucose range and reduced hyperglycaemia and hypoglycaemia events (43). Furthermore, a clinical decision tool reduced length of stay by 2.5 days (35) and a DKA protocol decreased hospital stay by 2.05 days (38). In a guideline derived educational programme, while length of stay was significantly reduced (p=0.042), severe hypoglycaemia increased (0.71% vs 0.24%%; p=0.089), and rates of moderate hypoglycaemia (4.6% vs 1.5%) significant increased (42) thus demonstrating that the management of the patients’ condition worsened. However, the study does stress caution in any intervention that significantly increases rates of hypoglycaemia. With regards to technology facilitated monitoring, continuous glucose monitoring showed significant clinical improvements on maternal glucose control with less time spent hyperglycaemic (32% vs 27%, p=0.0279) and hypoglycaemic (4% vs 3%; p=0.10) with further clinical improvements exhibited for obstetric and neonatal health outcomes including reduced length of stay (p=0.0091) (32). A technology based in-hospital control of glucose parameters also indicated significantly shorter length of stay (2.6 vs 1.6; p < 0.001) (32, 44). These studies are important as they demonstrate significant improvements in clinical outcomes and reduced length of hospital stay. Yet the most recent NaDIA report (49) confirms that clinical inertia still prevails with 18% of hospitals reporting no dedicated diabetes inpatient specialist nurses, and access to diabetes specialist pharmacists and dietitians a continued problem, 18% of medication charts having one or more insulin errors during hospital stay and almost 1 in 3 inpatient charts having at least one medication error, unrecorded capillary blood glucose levels and 3.6% of inpatients with Type 1 diabetes having developed in-hospital DKA at any point during their hospital stay. So, there is an urgent need to implement evidenced based clinical practice strategies such as those outlined here.

Clinicians have key roles in multidisciplinary teams and notable responsibilities in clinical decision making in the management of blood glucose in consultation with other members of the clinical care team, all of which are shown to reduce length of stay. Organisational and individual initiatives are important to make evidence-based guidelines accessible with integration at ward level and individual practitioner level (50). With the use of clinical management innovations, multidisciplinary collaborative care, influencing pathways through education and technology facilitated monitoring, the programmes described here demonstrate reduced length of stay for the inpatient with diabetes. These innovations have a practical application in clinical care to enhance clinical, economic, and patient outcomes and address length of hospital stay. Particularly, the multidisciplinary collaborative care programmes described here consist of multifunctional teams (31, 36, 41, 46, 51) an approach that has been shown to support high quality and safe care, patient and staff satisfaction and engagement, and organisational efficiency and innovation (52) and which many healthcare systems now embrace (53). Interdisciplinary collaboration is also an important facilitation of communication between health professionals wherein medication errors are commonly affected by communication breakdowns (54).

Evidence from research must influence and shape healthcare professions, and inform and underpin policy, professional decision making and nursing actions to improve healthcare (55). The importance of enabling clinicians to develop evidence-based practice was recently articulated in the Chief Nursing Officer for England’s strategic plan for research (55) in which the ambition is to create a people-centred research environment that empowers nurses to lead, participate in and deliver research, where research is fully embedded in practice and professional decision-making, for public benefit. Supporting a practical research environment has relevance for health and social care providers and deans of university faculties engaged in healthcare education and research (56). The best studies could be taking place and the best evidence could be available, but if it is not assimilated into clinical practice and actioned, clinical inertia will prevail. Research active hospitals have been shown to have better patient care outcomes, contribute to a better inpatient experience and have a positive effect on staff and service performance (57, 58). An aging population, chronic disease management and costs of care are demands prompting healthcare reform. Technology can no longer be seen merely as an adjunct to practice (59) as healthcare professionals embrace technological changes such as digital communications, telehealth approaches and artificial intelligence in a bid to improve efficiencies and integrate modernisation. More studies are examining the use of technology in the optimisation of inpatient care and service delivery utilising this important tool for the improvement of healthcare quality and safety (60). Frameworks such as Promoting Action on Research Implementation in Health Services (56) can guide implementation, but clinicians cannot do this alone and cooperation is also needed from organisational management. As healthcare systems work under increasingly dynamic and resource-constrained conditions, evidence-based strategies are essential to ensure that research investments maximize healthcare value and improve public health (61).

This review examines interventions that demonstrate reduced length of hospital stay and significantly improved inpatient diabetes management. From the perspective of clinical practice, these are key considerations within the context of a dramatically changing clinical landscape. With diabetes resulting in extended length of stay for inpatients, differing clinical strategies and the integration of digital technology that effectively reduce length of stay are vital and could enable faster hospital discharge and lower healthcare expenditure. Results from these studies could minimise the burden the health service is presently experiencing by implementing evidence-based clinical practice strategies to improve patient outcomes, reduce length of hospital stay and efficiency of hospital care. Change is possible but requires the will and investment of health services and clinical leadership (58).

The clinical practice outcomes of this review contribute to the evidence base for inpatient care and treatment outcomes. The implementation of evidence-based research can improve clinical practice and show that appropriate management can enhance clinical outcomes and reduce hospital length of stay and improve hospital efficiencies for the inpatient with diabetes. With the rising prevalence of diabetes and the growing costs of the condition and its complications, adaptable healthcare is necessary for the future. Investment in and commissioning of practices that reduce length of stay, patient flow and hospital costs have the potential to afford clinical benefits and influence the future of diabetes care. As length of stay is a key performance indicator for the service, these results should be a catalyst for healthcare managers, professionals, and educators to facilitate the translation of such evidence into practice as well as to inform future policy.

The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.

All authors listed have made a substantial, direct, and intellectual contribution to the work, and approved it for publication.

This review is part of a wider study, the Centre for Personalised Medicine, Clinical Decision-Making and Patient Safety funded by INTERREG VA and managed by the Special European Union Programmes Body.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.