Aims and objectives
The research project aims to explore the development pathway of pharmacists post registration in Great Britain (GB), from the foundation stage of pharmacy practice through to advanced pharmacy practice. It will additionally explore pharmacists’ experience of professional development and how this impacts the management of complex clinical cases in pharmacy practice.
The project will be conducted in a two phases; each part has a number of objectives.
Phase I – Foundation practice, progression and advancement
- To explore how foundation pharmacists progress through their careers and make the transition into advanced practice
- To define the interface between foundation and advanced pharmacy practice
- To determine the period of time taken for a foundation pharmacist to develop advanced practice skills, knowledge and behaviours, i.e. competencies
- To define complexity in pharmacy practice
- To explore the impact of foundation training on the management of complex clinical cases
 The interface is defined as the period of professional development when foundation training has been completed to the achievement of advanced pharmacy practice. The project will further define what achievement of advanced practice looks like in practice.
Phase II – Factors influencing progression to advanced practice
- To determine whether a structured programme supports foundation pharmacists progress to advanced pharmacy practice
- To explore motivators to progression
- To explore barriers to progression
- To explore the support required for progression and propose a model for support
Foundation practice, progression and advancement
Pharmacy needs to make better use of the pharmacy skill mix to be able to deliver better patient care focused around service delivery and integrated health provision. Prescription for Excellence (1) and Now or Never: shaping pharmacy for the future (2) presents innovative future models of pharmaceutical care. Pharmacists will need to ensure that they have the suitable resources, infrastructure, and education and development to enable them to deliver effective services.
It is acknowledged that the GB pharmacy workforce needs transformative growth in clinical capability, generalist and specialist skills development and must be sufficiently flexibility to adapt to changing patient and health system need. The education and development of the workforce should focus on the needs of patients and the public (3), building on a needs-based education model that is introduced at undergraduate level (4).
The review of post-registration career developments for pharmacy report published by Medical Education England outlines some key proposals for future work to ensure that the pharmacy workforce is sufficiently developed so that they will have the knowledge and skills to deliver “services of the future for patients and the public”. It highlights the need for enhanced and advanced practice within the pharmacy profession to meet the healthcare and pharmaceutical needs of the population and society (5).
A number of studies have identified the value and benefits a general level framework to support professional development of junior pharmacists in the NHS, highlighting the need for a common framework to support professional development across primary care and community practice (6–8). An advanced pharmacy framework additionally supports professional development and can be used alongside multisource feedback tools to recognise advanced practice (9–11). It is recognised that competency frameworks support professional and personal development, however are of limited use for regulation purposes (12).
The launch of the Royal Pharmaceutical Society (RPS) Foundation Programme and Faculty provides structured development pathway for pharmacists across all sectors. The Foundation Programme “provides professional support, networks, development frameworks, assessments and quality assured development opportunities for newly qualified pharmacists in their first 1000 days of practice” (13).
The Faculty is a professional recognition scheme for pharmacists. Individuals undergo an assessment and if successful are awarded with a stage and corresponding post-nominals, to recognise their
competence. The assessment comprises of: a practice-based portfolio; a peer assessment or review; an expert practice assessment and an oral peer assessment. Those who have 10 or more years of experience in practice, are not required to complete the oral peer assessment (14).
There are approximately 1000 newly qualified pharmacists using the Foundation Programme, and 402 RPS Faculty members (15). It is expected that pharmacists will progress into advanced practice upon completion of foundation training (16), however, it is not known if this is the case. Furthermore, it is not known whether this transition is seamless and/or continuous. In medicine, the training pathway is structured and clear. Doctors undertake a two-year Foundation Programme following graduation, then enter specialty training which last four to six years. Doctors have the opportunity to enhance their career by gaining credentials in special interest areas and subspecialty training (17,18).
There is limited reported evidence about career progression beyond foundation practice within pharmacy. As new frameworks for professional development emerge within pharmacy there is a need to evaluate their effectiveness and impact on pharmacists, organisations, practice and patient outcomes.
This becomes a priority with news that independent regulator for pharmacists, pharmacy technicians and pharmacy premises in Great Britain, General Pharmaceutical Council’s (GPhC), will introduce continuing fitness to practise in 2018 so that the public can be assured that pharmacists meet standards for safe and effective practice throughout their careers (19). The RPS has proposed that the Foundation Programme and Faculty meets continuing fitness to practice requirements for pharmacists (20).
The research project will explore the development pathway of pharmacists post registration in different sectors, from the foundation stage of practice through to advanced practice.
Complexity in pharmacy practice
The ageing population and increased prevalence of long-term conditions in England have a significant impact on health and social care. It is estimated that £5 billion in additional expenditure is required by the NHS to care for patients with comorbidities by 2018. However, the number of people with three or more long-term conditions, i.e. multimorbidity, in England is predicted to increase to 2.9 million in 2018 (21). A tailored approach to care is required for multimorbidity; this involves establishing patient’s preferences and values, and developing an individualised management plan (22).
 Comorbidity is defined as “the presence of more than one distinct condition in an individual” (51).
 Multimorbidity is defined as having 2 or more long term conditions (22).
Complexity is often associated with multimorbidity in the literature, however it is acknowledge that social and behavioural factors contribute to multimorbidity (23–25). Researchers have developed a complexity framework from definitions and descriptions of complexity found in the available literature to guide the approach to understanding patient complexity (23). A basic complexity score has additionality been developed to measure access to healthcare, thus providing clinicians with a measure of care (26).
There does not appear to be consensus on a definition of complexity, furthermore research into the management of complexity is limited.
The research project will additional explore experiences of professional development and how this impacts the management of complex clinical cases in pharmacy practice, to enable pharmacists to
demonstrate their contribution to patient care and how this evolves as they develop. Although outside the scope of this project, a tool may be developed to measure and evaluate pharmacy services; a valuable tool for employers, commissioners and policy makers. This may additional inform organisation planning and resource utilisation, which could result in quality improvement, efficiencies, financial savings, and perhaps even lead to new models of care.
Factors influencing progression to advance practice
Factors influencing progression from foundation pharmacy practice to advanced pharmacy practice are to be defined, however we can learn from what is known about pharmacy continuing professional development (CPD), with this being the current method pharmacy professionals keep their knowledge and skills up to date, and maintain and improve the quality of their practice (27,28).
CPD is learning through educational courses, work experience and practice which continues throughout one’s professional career (29). It is acknowledged that learning for professional development is complex (30). A number of motivators for CPD have been identified, including positive purpose of CPD, positive influence on working life, benefits for work, positive incentives, and feelings of being compelled to engage in CPD (31). Pharmacists generally agree with the principle of engaging with CPD, however the literature suggests that CPD is not generally accepted by all. Barriers to CPD include time, financial costs and resource issues, poor understanding of CPD, lack of facilitation and support for CPD, low motivation and interest in CPD, negative attitudes towards compulsory CPD, system constraints, and technical problems (29,31,32).
This can be further explained by the theory for adulthood learning. Motivators for learning include cognitive interest, social stimulation, communication improvement, social contact, educational preparation, professional advancement, family togetherness. Barriers to learning include costs associated with learning, time constraints, lack of confidence, lack of course relevance, low personal priority, personal problems (33). Significant barriers to professional responsibility and clinical confidence impacts the advancement of the role of the pharmacist (34).
By identifying factors, in particular barriers, that influence learning and professional development, solutions to overcome these barriers, in the form of an intervention, programme, support, resource or tool can be developed to aid progression.
In summary, this project will create new evidence about how pharmacists transition from foundation practice to advanced practice, adding to our understanding of this field. It will inform the development of policy and professional development programmes for pharmacists across GB, regardless of the sector they work in. It will additionally enable pharmacists to better describe the positive impact of foundation and advanced practice on patient care. Many countries have adopted the GB model for professional development (9,35,36); this research will be of significance to countries that want to learn from GB practice.
Plan of investigation
A literature review is being conducted using a systematic approach to identify what has been covered in the field by previous researchers and to identify gaps in the evidence (36–38). Pharmacy, medical and educational databases were used, including Google Scholar, JSTOR, Medline, ProQuest, PsycINFO, PubMed, EBSCOhost, CINAHL and Zetoc.
Search terms include a combination and variations of: pharmacy education, continuing professional development, foundation training, foundation practice, advanced practice, general level, advanced level, specialist, competence, competency, complexity. A search was also conducted in subject specific journals including the Pharmaceutical Journal, International Journal of Pharmacy Practice, Pharmacy Education, American Journal of Pharmaceutical Education, Journal of Pharmacy Practice and Research, and Medical Education.
References are managed on Mendeley version 1.16.1.
A multilevel mixed method will be employed for the research project. Mixed method research provides insight and understanding which single qualitative or quantitative methods might miss (40–43). It also produces more complete knowledge to inform theory and practice, compared to qualitative or quantitative methods alone, thus producing stronger and more credible studies (44). The quantitative aspects of the project will provide data of outcomes and experiences of the foundation training. Qualitative data will draw out views, thoughts and ideas of participants.
Quantitative and qualitative data have equal weight in this project, thus data will be collected continuously and in parallel (43). Figure 1 and 2 outlines how data will be collected at each of the two phases.
The population is pharmacists who are undergoing or have completed foundation practice in any pharmacy sector (clinical diploma or accredited RPS foundation programme) in Great Britain.
Probability and purposive sampling will be used in the research project. Both techniques will generate a sample that will address the overarching questions, more specifically, probability sampling will provide numerical data and a breadth of information generated by sampling units (42). Purposive
sampling will be used to identify those who are most typical of the population and to achieve comparability across different types of cases that focus on depth of information (42,45).
The sample size will vary for the two phases of the project. In qualitative research, it is recognised that the quality of information obtained from the sample is more important than the number in the sample (46).
Recruitment will be conducted through online channels and platforms, including professional fora and networks. Organisations that have links with foundation pharmacists, e.g. RPS Foundation Schools and Foundation providers, will be asked to disseminate information through their intranet and distribution lists. Consent will be obtained from participants for their involvement in the research project. Participants will be able to end their involvement in the project at any time.
Phase I – Foundation practice, progression and advancement
A prospective longitudinal study will be employed to collect qualitative and quantitative data about how foundation pharmacist’s progress over time. This study will be conducted over a 2-3 year period, this is because some foundation pharmacists will complete training at different points in the year.
Stratified purposive sampling of typical cases of pharmacists who are undertaking foundation training across different sectors (6 hospital pharmacists; 6 community pharmacists; 2 other sector (including primary care, industry)). A control group of pharmacists who are not undertaking foundation training (6 hospital pharmacists; 6 community pharmacists; 2 other sector (including primary care, industry)) will be additionally recruited.
Participants will self-assess their knowledge, skills and behaviours using the advanced pharmacy framework (APF) 3 months before they complete foundation training to obtain a baseline of their practice, and at regular intervals (every 6 months) until the majority of advanced competencies are achieved, which is anticipated to be 2 years.
A modified electronic version of the APF will be developed in Excel to enable participants to enter data on a structured template, thus ensuring consistency of recording.
Semi-structured one to one interviews will be conducted with participants every 12 months to explore their views on their progress. Interviews will be conducted by the same lead researcher to ensure consistency of approach. Interviews will be conducted face-to-face at a location and date that is convenient to participants to encourage participation.
An interview protocol will be designed to explore views of progression, views of complexity and how complex clinical cases are managed. Interviews will be transcribed verbatim by a transcriber. Themes will be drawn from the responses to provide a perspective of how the approach to the management of complex cases may change as a pharmacist progresses towards advanced pharmacy practice.
A pilot group of 5 pharmacists (2 community based pharmacists; 2 hospital based pharmacists; 1 pharmacist based in other sector) will be recruited to test the interview protocol. This will establish the validity of the questions and format, identify redundant questions, and highlights questions to be refined and improved, thus reducing non-responses.
To avoid bias, participants involved in the pilot group will not be involved in the main research. Data generated may inform the methodology.
Analysis will include:
- Comparison of APF self-assessment scores over time and across sectors
- Identification and comparison of themes from diaries/portfolios over time and across sectors
- Identification and comparison of themes from interviews over time and across sectors
- Comparison of progression across sectors
- Mapping of the management of complex cases as foundation pharmacists progress into advanced practice
- Comparison of management of complex cases over time and across sectors.
Phase II – Factors influencing progression to advance practice
A cross-sectional study will be employed to capture views of factors influencing professional development on completion of foundation practice in different settings and environments.
Purposive sampling will be used to recruit a heterogeneous sample of pharmacists undertaking foundation training (100 hospital pharmacists; 100 community pharmacists; 30 other sector (including primary care, industry)). A large sample has been chosen to account for attrition, non-respondents and non-responses, which could be up to 50% of the sample recruited (47). It may be difficult to recruit participants; snowball sampling will be used to recruit further participants if required.
A heterogeneous sample of pharmacists (100 hospital pharmacists; 100 community pharmacists; 30 other sector (including primary care, industry)) who are not undertaking foundation training will be recruited as a control group.
Participants involved in phase I will be excluded from this group.
A semi-structured questionnaire will be designed to explore motivators and barriers to progression. Motivators and barriers will be identified from available literature.
An online questionnaire will be administered through Survey Monkey. An online questionnaire has been selected because it is more cost effective than printing and posting questionnaires, although does rely on the computer literacy of the participants.
The pilot group recruited for phase I will test the validity of the questions and format for of the questionnaires. To avoid bias, participants involved in the pilot group will not be involved in the main research. Data generated may inform the methodology.
Focus groups will be conducted to explore views of support required for progression. Details of the the four focus groups (5 participants in each) are as follows:
Group A – Foundation pharmacists who are undertaking foundation training
Group B – Foundation pharmacists who are not undertaking foundation training
Group C – Advanced pharmacists who have undertaken foundation training
Group D – Advanced pharmacists who have not undertaken foundation training
Participants for group A and B will be randomly selected from the cross-sectional sample. Purposive sampling will be used to recruit participants for group C and D from the population of RPS Faculty members. Information about Faculty members are published on the RPS website.
The lead researcher will be the facilitator for the focus group sessions. A note taker will be recruited to capture verbatim discussions from the focus groups.
A semi structured interview guide will be developed to explore the type of support pharmacists at different stages of their career need for progression.
The pilot group recruited for phase I will again test the validity of the questions and plans for the focus. Again, to avoid bias, participants involved in the pilot group will not be involved in the main research. Data generated may inform the methodology.
Analysis will involve identification and comparison of motivators and barriers to progression across sectors. It will also identify what support is required by foundation pharmacists. This data will inform the development of a model for support and progression.
Statistical design and analysis
Data will be collected and recorded in Microsoft Access or Excel. Data will be inputted by the lead researcher to ensure consistency. Any missing values will be investigated as this could introduce bias (48).
Thematic analysis will be conducted for qualitative data obtained from the interviews and focus groups, using the constant comparative method (42). Data will be coded in NVivo.
SPSS will be used to conduct parametric significance testing to examine differences among cases, including t-tests and analysis of variance (ANOVA). Regression statistics will be performed to predict one value from another/several measured variable. Correlation statistics will also be performed, including Pearson product moment correlation and Spearman’s correlation coefficient (48).
Triangulation of the quantitative and qualitative datasets will corroborate the overall findings (49,50).
 Advanced pharmacists are recognised by the RPS Faculty with at least 2 years post qualification pharmacy practice experience.
 NVivo is a qualitative data analysis computer software package. The latest version will be used for analysis.
 SPSS (Statistical Package for the Social Sciences) is a computer software package for statistical analysis. The latest version will be used for analysis.
List of outputs and plans for dissemination
A full report and executive summary of phase I and phase II of the research project will be produced and shared with relevant stakeholders and policy makers including the RPS, Health Education England, NHS Education for Scotland and NHS Wales commission, GPhC, Pharmacy Schools Council, and employers. It may also be of interest to international bodies and associations, thus the report will additionally be shared with the International Pharmaceutical Federation (FIP). The Executive summary will also be shared with participants so they are aware of how their input has added to the evidence base in the field.
The executive summary will additional be shared with relevant expert advisory groups, including the RPS education expert advisory group, RPS pre-registration training advisory group, the RPS hospital Expert Advisory Group, and the UK Clinical Pharmacy Association (UKCPA) education and training group. An annual report of my progress will also be submitted to relevant funders.
A letter of thanks will be sent to participants with a factsheet summarising the key findings. They will be invited to share the factsheet with colleagues and relevant stakeholders. The factsheet will also be disseminated on relevant professional networks.
Topic of conference abstracts, posters, and presentations, and research papers will include:
- The interface between foundation and advanced practice
- Development of a complexity scoring tool for pharmacy practice
- Factors influencing advancement
- Impact of foundation practice on patient care
Conference abstracts and posters will be submitted to the Pharmacy Education conference, RPS annual conference, the Health Services Research and Pharmacy Practice conference and the International Pharmaceutical Federation World Congress Conference of Pharmacy and Pharmaceutical Sciences. Posters and presentations will additionally be presented at UCL’s School of Pharmacy PhD research days (biannual). At least one poster will be submitted to UCL’s annual poster competition.
Papers will be published in Pharmacy Education, International Journal of Practice and Policy, Pharmaceutical Journal.
In line with UCL’s policy, a copy of the PhD thesis will be made available at the institution’s library, and details of the research will be added to the research portal and open access repository (UCL Discovery).
Various aspects of the research project will additionally be shared on RPS Map of Evidence and other research databases, such as ResearchGate, so that fellow researchers and my UCL research peer group can learn from the methodology and findings, and contribute to the evidence base by undertaking further research in the field.
I will additionally explore more creative platforms for dissemination of information, such as blogging. Advice on intellectual property will be sought, so that outputs of my project are adequately protected.
- The Scottish Government. Prescription for Excellence A Vision and Action Plan for the right pharmaceutical care through integrated. Edinburgh; 2013.
- Smith J, Picton C, Dayan M. Now or Never: Shaping Pharmacy for the Future. London; 2013.
- The Royal Pharmaceutical Society. Transforming the Pharmacy Workforce in Great Britain : The RPS Vision. London; 2015.
- International Pharmaceutical Federation. Quality Assurance of Pharmacy Education : the FIP Global Framework. The Hague; 2014.
- Howe H, Wilson K. Review of post-registration career development: Next steps. 2012.
- Antoniou S, Webb DG, McRobbie D, Davies JG, Wright J, Quinn J, et al. A controlled study of the general level framework: Results of the South of England competency study. Pharm Educ. 2005;5(3-4):201–7.
- Coombes I, Avent M, Cardiff L, et al. Improvement in Pharmacist’s Performance Facilitated by an Adapted Competency-Based General Level Framework. J Pharm Pract Res. 2010;40(2):111–8.
- Mills E, Farmer D, Bates I, Davies G, Webb DG. The General Level Framework: use in primary care and community pharmacy to support professional development. Int J Pharm Pract. 2008 Oct 1;16(5):325–31.
- Coombes I, Bates I, Duggan C, Galbraith KJ. Developing and recognising advanced practitioners in australia: An opportunity for a maturing profession? J Pharm Pract Res. 2011;41(1):17–9.
- Coombes I, Kirsa SW, Dowling H V., Galbraith K, Duggan C, Bates I. Advancing pharmacy practice in Australia: The importance of national and global partnerships. J Pharm Pract Res. 2012;42(4):261–3.
- Costa MH, Shulman ROB, Bates I a N. A credentialing process for advanced level pharmacists : participant feedback. Pharm J. 2012;288(May):1–5.
- Wright D, Morgan L. An Independent Evaluation of Frameworks For Professional Development. Report of the MPC Workstream 2 Project : Independent evaluation of competency frameworks within pharmacy education in the UK. 2011.
- The Royal Pharmaceutical Society. RPS Foundation Pharmacy Framework Handbook: A handbook for professional development in foundation practice across pharmacy. London; 2014.
- The Royal Pharmaceutical Society. The Faculty Member Handbook: A handbook to support RPS members through their development and Faculty Membership. 2014.
- Society RP. List of current Faculty members [Internet]. 2016 [cited 2016 May 3]. Available from: http://www.rpharms.com/faculty-membership/list-of-current-faculty-members.asp
- The Royal Pharmaceutical Society. Getting Started with RPS Career Development Programmes. London; 2016.
- Shape of Training. Securing the future of excellent patient care. 2013.
- The Gold Guide. A Reference Guide for Postgraduate Specialty Training in the UK. 2010.
- General Pharmaceutical Council. Continuing Fitness to Practise [Internet]. 2016. [cited 2016 May 2]. Available from: https://www.pharmacyregulation.org/registration/continuing-fitness-practise#cftp
- The Royal Pharmaceutical Society. CPD, CFtP, the GPhC and Faculty/Foundation. London: The Royal Pharmaceutical Society; 2016.
- The Kings Fund. Long-term conditions and multi-morbidity [Internet]. [cited 2016 May 2]. Available from: http://www.kingsfund.org.uk/time-to-think-differently/trends/disease-and-disability/long-term-conditions-multi-morbidity
- National Institute for Health and Care Excellence. Multimorbidity : clinical assessment and management. 2016;(May).
- Schaink AK, Kuluski K, Lyons RF, Fortin M, Jadad AR, Upshur R, et al. A scoping review and thematic classification of patient complexity: offering a unifying framework. J Comorbidity. 2012;2(1):1–9.
- Mount JK, Massanari RM, Teachman J. Patient Care Complexity as Perceived by Primary Care Physicians. Fam Syst Health. 2015;33(2):137–45.
- Loeb DF, Binswanger IA, Candrian C, Bayliss EA. Primary care physician insights into a typology of the complex patient in primary care. Ann Fam Med. 2015;13(5):451–5.
- Upshur REG, Wang L, Moineddin R, Nie JX, Tracy CS. The complexity score: towards a clinically-relevant, clinician-friendly measure of patient multi-morbidity. Int J Pers Cent Med. 2012;2(4):799–804.
- General pharmaceutical council. Standards for continuing professional development. 2010.
- General Pharmaceutical Council. Review of Continuing Professional Development. London; 2015.
- Donyai P, Herbert RZ, Denicolo PM, Alexander AM. British pharmacy professionals’ beliefs and participation in continuing professional development: A review of the literature. International Journal of Pharmacy Practice. 2011. p. 290–317.
- Black PE, Plowright D. A multi-dimensional model of reflective learning for professional development. Reflective Pract. 2010;11(2):245–58.
- Laaksonen BR, Duggan C, Bates I. Overcoming barriers to engagement in continuing professional development in community pharmacy : a longitudinal study. Pharm J. 2009;282:44–8.
- WARD PR, Seston EM, WILSON P, Bagley L, Ward R, Seston EM, et al. Perceived barriers to participating in continuing education : the views of newly regstered community pharmacists. Int J Pharm Pract. 2000 Sep 22;8(3):217–24.
- Hawk TF. Learning in Adulthood: A Comprehensive Guide. Academy of Management Learning and Education. 2011. p. 168–70.
- Frankel GEC, Austin Z. Responsibility and confidence: Identifying barriers to advanced pharmacy practice. Can Pharm J. 2013;146(3):155–61.
- Rutter V, Wong C, Coombes I, Cardiff L, Duggan C, Yee M-LL, et al. Use of a general level framework to facilitate performance improvement in hospital pharmacists in Singapore. Am J Pharm Educ. 2012 Aug 10;76(6):107.
- Meštrović A, Staničić Ž, Hadžiabdić MO, Mucalo I, Bates I, Duggan C, et al. Evaluation of Croatian community pharmacists’ patient care competencies using the general level framework. Am J Pharm Educ. 2011;75(2).
- Jesson J, Lacey F. How to do (or not to do) a critical literature review. Pharmacy Education. 2006. p. 139–48.
- Booth A, Papaioannou D, Sutton A. Systematic Approaches to a Successful Literature Review. 1st ed. London: SAGE; 2012.
- Louise D. Systematic Approaches to a Successful Literature Review. Nurse Educ Pract. 2013;13(3):e6.
- Creswell JW. Research design Qualitative quantitative and mixed methods approaches. Res Des Qual Quant Mix methods approaches. 2003;3–26.
- Clark P. Mixed Methods Approaches : Controversies are Still Here . (4):275–80.
- Teddlie C, Tashakkori A. Foundations of Mixed Methods Research: Integrating Quantitative and Qualitative Approaches in the Social and Behavioral Sciences. Book. 2009.
- Creswell JW. Educational research: Planning, conducting, and evaluating quantitative and qualitative research. Educational Research. 2015.
- Johnson RB, Onwuegbuzie AJ. Mixed Methods Research: A Research Paradigm Whose Time Has Come. Educ Res. 2004;33(7):14–26.
- Teddlie C, Yu F. Mixed Methods Sampling: A Typology With Examples. J Mix Methods Res. 2007;1(1):77–100.
- Sandelowski M. Sample size in qualitative research. Res Nurs Health. 1995;18(2):179–83.
- Gorard S. Quantitative methods in educational research: the role of numbers made easy. British Educational Research Journal. 2001.
- Cohen L, Manion L, Morrison K. Research Methods in Education. London: Routledge Taylor & Francis Group; 2011.
- Creswell JW, Plano Clark VL. Choosing a Mixed Method Design. Designing and Conducting Mixed Methods Research. 2007;58–89.
- Plano Clark VL, Ivankova N V. Mixed Methods Reserach. 3rd ed. London: SAGE; 2016.
- Valderas JM, Sibbald B, Salisbury C. Defining Comorbidity: Implications for Understanding Health and Health Services. Ann Fam Med. 2009;(7):357–63.