Oral health problems among palliative and terminally ill patients: an integrated systematic review

Search strategy was devised by the research team with chosen five databases in specific period in English language with comprehensive search terms to not omit any relevant potential primary studies. The detailed data sources are explained in Table 1.

Inclusion criteria specified that studies must be: (1) in full-text, (2) published between years 2000 to 2017, and (3) primary articles focusing on palliative patients and their oral conditions.

Figure 1 illustrates Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart of study selection process [8]. The initial combined search identified 25,311 articles from 5 databases and from other sources (manual searching and through references). Removal of duplicates resulted in 13,263 studies. Screening of relevant abstracts resulted in 1230 studies. Further screening for inclusion criteria resulted in 67 studies which were read to ensure applicability to our study. This resulted in 28 articles being excluded. All reviewers screened and discussed preliminary findings to reach a consensus on studies to be included that resulted in total of 19 articles for further analysis.

In the data extraction process [9], study details were extracted into a table (Table 1). This was done by two reviewers (Z.R., and D.R.). All reviewers discussed each article to reach consensus regarding the study details. For each included study, the following information was extracted: author(s), year published, title, purpose, setting, participants, study design, and oral conditions present. The impact, management and challenges of oral problems among palliative patients were also extracted and summarized according to our research questions.

As our review included both qualitative and quantitative studies, we did not use any scoring for assessing the quality of studies included. Rather, the quality of the identified studies was assessed using Joanna Briggs Institute (JBI) critical appraisal tool [10]. As a result, only studies that were thoroughly appraised (have clearly defined inclusion criteria, study subjects and setting described in detail, exposure measured in a valid and reliable way, standard criteria used for measurement of condition, identification of confounding factors, outcomes measured in a valid and reliable way, and appropriate statistical analysis used) and agreed by all involved reviewers were included in this systematic review to write the findings.

Extracted data from all included studies were analyzed using the Whittemore and Knafl [9] principles of integrative review with four stages: data reduction, data display, data comparison, and conclusion and verification. At data reduction stage, all 19 primary sources included in the integrative review were divided into subgroups; initially based on types of study (qualitative and quantitative), sample (cancer patients, non-malignant palliative conditions and oral conditions among palliative patients) and then by a predetermined conceptual classification aligning with the aims of this review and then analyzed by topic. Each primary source was reduced to a single page (available on request from authors). This helped us to systematically compare primary sources on specific issues, variables and sample characteristics. It also allowed us to organize the data into a manageable framework. At stage 2 (data display), the single page data from the 19 included studies was extracted and displayed in the form of a table (see Table 1). This helped us to visualize the patterns and relationships between and within primary data sources. At stage 3 (data comparison), we used constant comparison as a method of an iterative process of examining data to identify themes that had similar patterns and relations. Finally at stage 4 (conclusion and verification), patterns using primary data were verified and any similarities, differences and any spurious findings were identified, in order to ensure that valuable information was not lost. Five consecutive meetings were held in order to identify and reach a consensus on the final themes.

Overall, 19 articles were included in this review. The majority of the participants were cancer patients (n = 14). Studies reporting on oral conditions among palliative patients are summarized in Table 1. Of the included studies, 16 were quantitative studies [5, 11‐24], and 3 were qualitative studies [25‐27](Table 2).

Out of 19 studies, 13 reported xerostomia or dryness of mouth [5, 11, 14‐17, 19, 23‐28]. Eight studies reported candidiasis or oral thrush [11, 14, 16, 20, 23‐26]. Six studies reported dysphagia or swallowing difficulties [15, 17‐19, 22, 26]. Five reported mucositis [13‐15, 21, 22] and 5 orofacial pain [5, 17, 22, 23, 28]. Four studies reported taste changes [5, 23, 25, 28] and two reported ulceration [5, 26], coughing [17, 18] and oral discomfort [25, 26].

Other oral conditions reported are stomatitis [11], salivary hypofunction [5], mucosal erythema [5], fungal infection [5], periodontitis [12], cold sores [14], dental caries [16], gingival inflammation [16], tongue coating and inflammation [16], bleeding spots [16], plaque [17], food particles and fungus infection [17], sores and scabs [17], viscous ropy saliva and chapped lips [17], halitosis [17], problems using dentures [17], problems with oral secretions [18], dysarthria [19], oral yeast carriage [24], mucosal friction [25], and bouts of ulceration and infection [27].

Table 3 presents our findings associating the social and functional impact of oral conditions [5, 25‐28]. Our review also revealed social and functional impact of having oral conditions among palliative patients. Social impact include feeling worried, bothered, a feeling of less satisfying life, shame, anxiety, depression, increased feelings of being a patient rather than a person, not wanting people to be around them which affected their social interaction and resulted in loneliness [5, 25‐28]. Functional impact include difficulties in swallowing, speaking and eating, food restriction, sense of oral dryness and pain, which resulted in lack of food enjoyment [5, 26, 28].

Table 4 presents our findings on the management of some oral conditions among palliative patients and their effectiveness [11, 15, 17, 19‐23] Our study revealed that the common management options for xerostomia are drug and medical treatments [15], lubricating lips and mucosa [17], acupuncture [19], and standard oral care which improved dry mouth (in 80% or more) of the patients [11]. For candidiasis, a single-dose fluconazole 150 mg via mouth was found to be very effective as the symptoms decreased significantly (P < 0.001) in most patients [20], and local antifungal treatments were reported to be efficacious in 78.1% of the patients [23]. A substantial improvement of dysphagia was also observed after fifth treatment of acupuncture [19], however, its management using step-based pharmacological intervention and topically acting drugs caused worsening of swallowing and soreness of mouth [22]. Also, the management of mucositis using step-based pharmacological intervention and topically-acting drugs did not improve the oral condition [22], however, an indomethacin oral spray has been proven to relieve pain after 25 min [21].

Table 5 presents our findings on the challenges in treating oral conditions among palliative patients [17, 18]. Only 2 of the included papers addressed the challenges in treating oral conditions among palliative patients. Kvalheim et al. (2016) found that some of the challenges were the lack of knowledge/routine, patient cooperation, resources, priority given to oral problems, as well as difficulty in accessing the mouth and retching. Bogaardt et al. (2015) observed underestimation of reported oral problems among palliative patients by rating significantly lower incidence and severity problems by the nursing staff compared to the patients’ relatives.