The potential contribution of mixed-method research to critical care nursing

The use of mixed-method research (MMR) within health care is growing, influenced by global policies that place emphasis on value for money and the need for translational research that informs evidence-based practice in meaningful way. Its particular strength is to support the development, implementation and evaluation of interventions (Doyle et al., 2016). MMR is an interesting approach for nurses because of the richness of using a combined approach that utilizes elements of both quantitative and qualitative methods (Moule and Goodman, 2014). Two divergent approaches are used in one single study (Boswell and Cannon, 2011). The required effect is that one approach synergistically enhances the other (Moule and Goodman, 2014). This combination provides contrasts and comparisons among findings by exploring different perspectives of the same issue. MMR may be described as either sequential exploratory, sequential explanatory or convergent (Pluye and Hong, 2014). In the latter approach, both key elements (qualitative and quantitative) occur at the same time. With the exploratory approach, the qualitative element comes first and helps to develop the quantitative data collection tool (usually a survey) that follows. In the explanatory approach, the qualitative findings are used to substantiate the main findings (Pluye and Hong, 2014).

Complex, detailed and time consuming (Creswell and Plano Clark, 2018), MMR is a useful research method for those nurses who study complex health problems in different population types and groups (Bliss, 2001), especially those that cannot be resolved by simply using qualitative or quantitative methods alone (Andrew and Halcomb, 2009). Chronic diseases, health care needs of those with chronic kidney disease or those undergoing dialysis are some examples of complex research areas (Creswell et al., 2011), which often require varied investigative methodologies (Andrew and Halcomb, 2009). A deeper understanding of patients' experiences and clinical issues is also possible and necessary (Rath et al., 2017). The added methodological value of MMR in shaping clinical care is that it provides room to expose the stakeholder's voice, whether this is patient, family, nurse or other health personnel. While this can be carried out in traditional qualitative studies, these studies do not have the power to convince as they are subjective. By supporting qualitative findings with quantitative research and vice versa, there is a greater chance that the stakeholder's voice can be validated.

Critical care nurses are on the cutting edge of many new developments and thus are well placed to learn from the rich results that an MMR study can demonstrate. Some clinical examples from critical care are useful to illustrate the potential contribution of MMR, particularly for junior nurses. For example, a recent MMR study focused on how critical nurses experienced the use of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in mechanically ventilated patients (Steinseth et al., 2018). This MMR study interestingly highlighted that ICU nurses who tended to underestimate the importance of the CAM-ICU were mostly the ‘novice’ or the ‘expert’ ICU nurses. The ‘novice’ (or newly graduated) nurses lacked knowledge of how to confidently use the tool and were unsure about its usefulness and therefore preferred to trust their own clinical assessment procedures. On the other hand, the ‘expert’ ICU nurses (i.e. those with many years of experience) preferred to rely on their own intuitive interpretation of the situation and clinical judgement (Steinseth et al., 2018). This MMR study enabled the highlighting of the importance of a deep understanding of the data and not just taking findings at face value. Rather than a simple interpretation of non-use of the scale, greater understanding of the reasons for non-use were identified that could help improve future uptake. Further development of this practice, based on these findings, could include, e.g. explanatory notes for novices and exploration of methods to integrate the assessment within expert intuitive practice. This clearly shows the role that MMR can play in comprehensive evaluations of new interventions.

MMR also permits greater exposition of objective data that can help greatly with practice improvement. Nydahl et al. (2015), e.g. uncovered barriers to patients using diaries in ICU. This led to greater development and use. Pattison et al. (2018), in their MMR study, showed how, in ICUs, the use of a diary placed at the patient's bedside table provided family members and health professionals the opportunity to write comments that would ‘fill the gaps of missed time’ while the individual patient was unconscious. Interviews with the patients about the usefulness of the diary and its contents showed how it helped them recover from their post-traumatic stress symptoms. However, conversely, through their MMR study, Aitken et al. (2017) found that the use of diaries in ICUs was not always perceived as beneficial by patients and family members to address post-intensive care psychological distress because some did not wish to remember ‘how it was’. Therefore, Aitken et al. (2017) reached the conclusion that it is first necessary to identify which patients and family members were more suited to diary use in order to be used safety and effectively (Aitken et al., 2017). Thus, MMR offers an opportunity to place the patient and his or her family at the centre of the health care setting by giving voice to their feelings and experiences and also permits a consideration of local culture, which is not always possible in larger empirical studies (Pattison et al., 2018).

This patient centeredness is also evidence in a recent MMR study was conducted by Elliott et al. (2019), who explored the incidence and impact of cognitive impairment in patients following admission to the ICU. Using the combination of methodologies, they identified various issues related to patients' concerns, including fatigue, frailty and muscle weakness, that became evidence after their ICU episode during their recovery. This helped health professionals understand what kind of specific care to provide to each patient according to concerns and to help them design a personalized ICU discharge plan (Elliott et al., 2018).

MMR can also put the ‘meat on the dry bones’ of quantitative research, providing for a more detailed explanation of research findings and essentially validating both findings (Doyle, 2016). For example, Lima et al. (2018) recently examined critical care nurses' experience of paediatric death using MMR, which was very illuminating in terms of enriching the findings and providing explanations for the trauma that nurses experienced. Although the researchers used a valid quantitative instrument to identify this trauma, it did not have the sensitivity to pick up the nuances explained in the interviews. In fact, the impact of a child's death appeared quite minimal as particular psychological behaviours that were measured (e.g. hyperarousal, avoidance) did not rate highly in the quantitative arm of the study. The experience of a child's sudden death did not appear frequent (less than 50% of nurses had witnessed more than five within a 6-month period). However, the interviews demonstrated a different picture. Two central themes, ‘emotional impact’ and ‘circumstances that affected the emotional impact’, indicated that nurses were deeply affected by the experience. ‘I took it really bad’, ‘I ruminate over it’, ‘...a horrific weekend’ are words that demonstrate the deep, lasting, emotional effect of a child's death on nurses, who in fact felt quite unsupported (Lima et al., 2018:p. 44). Thus, MMR permitted a more in-depth understanding of this phenomenon that could better inform local practice development and support.

The use of MMR is growing worldwide, and clear evidence of its usefulness in critical care nursing is evident. MMR supports new debates and offers guidance and understanding for nursing practice. It has much to offer critical care nurses who are seeking to uncover and improve practice. More needs to be done to encourage its use, especially where the patient or family voice is essential or where nurses' expert practice might inform policy. At the same time, it must be noted that there needs to be consideration of the risk of interpreting and using MMR evidence in isolation when compared with the strictest criteria for best evidence in practice. A rigorous approach that involves the whole health care team, appropriate quality appraisal and relevant stakeholders is needed. Ultimately, researchers and non-researchers need to be more open about the potential for MMR research, particularly to the inclusion of qualitative elements within empirical studies. This would widen our understanding of health care in a more holistic way and also improve the inclusion of patient voices in health care and research that is currently being encouraged.