The Value of Nursing Competence and Staffing for Patients in Critical Care: A Scoping Review

Study design

A scoping review was conducted to present a descriptive overview of findings without synthesizing evidence from different studies (13–15). Scoping of the most current critical care nursing literature and the development of instruments for measuring nursing workload increased in use after 2005. Therefore, the search limits were set for articles published between 2006 and May 2023. CINAHL, Medline, Embase, the British Nursing Index, and SweMed+ were searched for suitable primary research studies with a quantitative design in English. A comprehensive search strategy was used to identify published studies by using the keywords “acute care”, “infection control”, “length of stay”, “treatment errors”, “adverse health-care event”, “adverse events”, “skill mix”, “personnel staffing and scheduling”, “critical care nursing”, “clinical competence”, AND/OR “risk management”. The Medline search strategy is presented in Appendix I. The search was adapted for each subsequent database.

Study selection

The articles included in this review met the following criteria: peer-reviewed articles available in full text, primary research, studies published in English or Scandinavian language, studies that focused on nurses working in critical/intensive care and nurse-sensitive outcomes for ICU patients. Studies that focused on general nursing or on specific groups such as neonates or paediatric patients were excluded (Figure 1). This review study is reported in accordance with the PRISMA 2000 checklist. The titles and abstracts of the included studies were independently assessed by two of the authors for eligibility against the inclusion and exclusion criteria and categorized as “possibly relevant” or “clearly not relevant”. This process was repeated with full-text studies. New references were found and followed the same stages for the inclusion process (Table 1). Only small disagreements occurred and were discussed in the research group until consensus was reached. The quality assessment based on the Critical Appraisal Skills Programme (CASP) checklist was independently performed by two authors.

Ethical considerations

This is a literature review, and no approval is required. All included studies had clearly identified ethics.

How is nursing competence in ICUs described?

The educational level of nurses working in ICUs is poorly described in studies in both nursing and multidisciplinary journals. Three studies described nurses’ competence level as formal education with a bachelor’s (33) or master’s degree (25,35). Two studies used the term “nurse” or “nurse in ICU” (24,26) without any description of the level of competence or education in critical care. Other studies used group terms such as “healthcare teams” (19), frontline staff (23), coronary care unit staff, or healthcare workers, both covering nurses and technicians (17).

Level of competence was also described in broad terms such as ICU nurses qualified to manage ventilators (16) or able to perform dialysis, mobilization, and weaning from mechanical ventilation (27). Some studies used more specialized terms such as “nurses with certification for the unit” (22), CCNs and intensive care nurses (ICN) (25,35), and ICU nurses (16,26,28) without describing the educational level. In one study, nurses were mentioned only as the product of a scoring system, without any further description of the level of competence (23).

The term skill or skill mix is used in several studies without the definitions of the skills involved (19,30,32). Only one study (30) distinguished between direct care and supernumerary nurses or those in administrative positions. Therefore, nurse competence was poorly described, educational level was often not mentioned, and several job titles were used, making it almost impossible to precisely interpret nursing competence.

How is nurse staffing in ICUs described, applied, and measured?

In the 21 studies (Table 1), we found different descriptions of nursing time consumption, such as RN hours per patient day (20,32) and nursing hours per patient day (33). Some studies used staffing numbers such as nurse-to-bed ratio (30), number of staff, and number of patients seen daily (23,30).

A fixed nurse-to-patient ratio was mentioned in six studies. The nurse-to-patient ratio was also included if a tool was used to assess nurse staffing in ICUs. The tools used were the Nine Equivalents of Nursing Manpower Use Score (NEMS) (23), the Nursing Care Recording System (NCR11) (27), the Therapeutic Intervention Scoring System (TISS-28) (24,29,36) or TIS (21), TISS-76 (26), ICNSS (26), and the Nursing Activities Score (NAS) (17,28). These tools measure the nursing requirements for individual patients and recommend the number of nurses in terms of nursing intensity and workload.

Some studies did not clearly state the number of nurses available, the number of nurses required, or the assessment tools used. Increased use of validated tools from 2012 was found in studies that assessed patients’ needs for care, rather than simply considering nurse-to-patient ratios (17,26–28,35).

How are nursing competence and staffing in ICUs associated with nurse-sensitive outcomes?

Nurse staffing correlated with nurses’ workload and infections as nurse-sensitive outcomes (Table 1) (16–23). Nurse staffing also correlated with ADEs or medication errors (19,23–24), unplanned extubation, or line removal (23,25). High nurse workload (i.e. caring for twice the usual number of patients) was related to the spread of nosocomial infections measured using TISS-28 in a 3-year prospective study from Slovenia (36). Kendall-Gallagher and Blegen analysed data from a large national data set of 15,846 patients from the United States and found that the incidence rate of catheter-associated urinary tract infections was associated with increased overtime and decreased if the proportion of certified nurses was higher (19). They also found a significantly lower incidence rate of central line-associated bloodstream infections if the ICU had more RN hours per patient day. The same result was found by Thompson et al. (20). If the ICU had more than 20 RN hours per patient day, it also had a lower incidence rate of central line-associated bloodstream infections. Kendall-Gallagher and Blegen (19) and Dancer et al. (21) examined the incidence of hygiene failures and found an association with understaffing, which means high nurse workload.

The incidence rate of ventilator-associated pneumonia in Europe decreased when the nurse-to-patient ratio was greater than 1:1 (16), although no significant differences were found after adjustment for confounders (i.e. knowledge and competence in ventilators). In Sweden, decreased time on ventilator was associated with a higher CCN-to-patient ratio, but the study did not report on any tools used to assess workload (25). A cohort study of patients with infections in an ICU in Switzerland found that low nurse staffing was associated with a risk of infections and that infections could be prevented by maintaining higher staffing levels (22). All nurses working in ICUs in this study were either trained or trainees in critical care. A later study found that excessive nursing workload, measured using NAS, was the main risk factor of healthcare-associated infections (17). In a study from Italy, Lucchini et al. found no link between NAS results and the risk of developing pressure ulcers (28).

The next nurse-sensitive outcomes of interest were ADEs or medication errors, which are considered determinants of patient safety and quality of care (19,23–24). In Belgium, ADEs were found to be associated with the mean severity of illness (Acute Physiology and Chronic Health Evaluation II [APACHE-II] and Sequential Organ Failure Assessment score [SOFA score] ) and nursing workload [TISS-28]. The incidence rate of ADEs was significantly higher on days when the nursing workload was high (24). Fewer hours of nursing care per patient day were related to a higher incidence rate of ADEs in a random sample of 48 ICUs in the United States (19). One study investigated the safety climate and found that frontline staff (i.e. nurses) who could prevent errors and who made safety a priority contributed to a reduction of medical errors (i.e. ADEs) (23).

At the patient level, dislodgement of tubes, lines, catheters, and drains was significantly related to workload assessed using NEMS (23). Unplanned extubation was more frequent (3–5.7%), with a lower nurse-to-patient ratio, especially in units not allowing physical hand restraints (25).

In research on safety climate, ICUs measure nurse-sensitive outcomes in terms of length of ICU stay (27) or mortality (20,26,29–34). In Denmark, a RCT by Laerkner et al. suggested that a 1:1 nurse-to-patient ratio and a no-sedation policy might result in lower costs related to shorter length of hospital stay (27). West et al. described survival rates and, after controlling for patient characteristics and workload, found that higher numbers of nurses per bed were associated with higher survival rates (30). Nursing hours per patient also affected the mortality rate in a study in Belgium (24). In Finland, Jansson et al. found that nursing workloads (TISS and ICNSS) were significantly higher in patients with multiple-organ failure and in non-survivors over a 10-year period (26). In Korea, additional patients per RN were associated with increased odds ratio for mortality (34). A lower mortality rate was reported with more nursing hours per patient (33). The leaders described the patterns of interaction to achieve patient outcomes (35) and especially with an increase number of infection (36).

Studies that used tools for workload were more likely to report significant patient outcome results (17, 23–27). The incidence rate of nosocomial infections increased when nurses’ workload (measured using NAS) was high and their level of competence was low (17). The incidence rate of ADEs increased with a higher workload (measured using TISS-28) or lower educational levels among nurses (24). The incidence rates of dislodgement of tubes, lines, catheters, and drains increased with higher workload (NEMS) and lower nurse-to-patient ratio (23,25). The length of hospital stay was shorter when patients were not sedated for ventilation, and this was also associated with a lower workload (NCR11) (27). Multiple-organ failure and mortality were associated with high workloads (TISS and ICNSS) (26).

Limitations and strengths

A potential limitation of this study is that we only searched for studies published in English and Scandinavian. It is possible that relevant studies were published in other languages. A weakness of our review was that two studies (22,30) had results from the data collection based on the same patients from one ICU in Switzerland. A scoping review has inherent limitations because the focus is to provide breadth rather than depth of information on a particular topic (13,15). As such, a quality appraisal is generally not conducted in a scoping review. However, this method was appropriate given that our objective was to map out the evidence on how levels of nursing competence and staffing in ICUs were described and associated with nurse-sensitive outcomes in the literature. A strength of this study was the widespread inclusion of journals and the inclusion of both small and large studies in several countries (13). Further studies should investigate CCNs and how their competence in direct care affects nurse-sensitive outcomes in ICUs.

Contributions

SKS and BS searched and screened for studies in databases and used checklists for quality control (CASP). SKS and JB performed a review of the literature according to the PRISMA checklist. EG, SKS, and BS drafted the manuscript. SKS, SF, BSH, JB, and EG were active in the writing process and approved the final version.

Funding source

This research was funded by the Norwegian Nurses Organisation Professional Interest Group of Intensive Care Nurses and the first author’s hospital and university workplace.

Ethics statement

Ethics approval was not required for the scoping review of the literature.

Conflict of interest

The authors have no past or present affiliation with any parties who would have an interest in the outcome of this review, which could constitute a conflict of interest.

Relevance to clinical practice

• Advanced nursing competence in ICUs must be better described in research and linked to nurse-sensitive outcomes.
• A validated tool to assess patients’ need for care and nurses’ workload is necessary to measure the quality of nurse-sensitive outcomes in critical care.
• It is important to enable critical care nurses (through post-graduate qualifications or a master’s degree) to undertake research to show and continuously improve their impact on the treatment and care of patients.