INTERVENTIONS
3.3 APPROACHES FOR GENERATING THEORY OF THE HEALTH PROBLEM
3.3.2 Empirical Approach
Thus, theories prevent the danger of (1) mislabeling and vaguely defining health problems, (2) missing or omitting important determinants; and (3) misinterpreting associations (specifically bivariate ones that link the problem to one determinant) between the determinants and the problem, all of which have the potential to mis- lead the design of interventions. Middle range theories do not only explain the path- ways linking the determinants to the problem, but also point to the context under which the problem is experienced and maintained, and the pathway is induced. Var- iations in the pathway across clients and contexts highlight the need to adapt or tailor the design of interventions. Briefly, theories are powerful tools to understand the health problem and to make informed decisions when designing interventions (e.g.
Aráujo-Soares et al., 2018; Bleijenberg et al., 2018; Medical Research Council, 2019).
3.3.1.4 Limitations
The theoretical approach has some limitations in gaining a comprehensive under- standing of the health problem. The reliance on one single middle range theory con- strains the perspective on the nature and determinants of the problem to those identified in the theory. Therefore, additional factors (in particular contextual or environmental) that may contribute to the problem could be missed; this limits the capacity to account for all possible determinants pertinent to complex problems experienced by particular client populations in particular contexts. For many health- related problems there is a limited, if any, number of relevant middle range theories that provide an adequate understanding of the problem and all its determinants.
Further, of the available middle range theories, a few have been subjected to exten- sive empirical test across the range of client populations and contexts, and for those tested (e.g. transtheoretical model), the results are often mixed.
Middle range theories may have limited utility if they are not supported empiri- cally. The theoretical approach can be complemented with the empirical approach to gain a comprehensive and accurate understanding of the health problem as actually experienced in the target client population and context.
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Results of descriptive cross-sectional studies indicate the prevalence of the problem in different client populations and clarify the nature of the problem, its indi- cators, and level of severity as reported by clients presenting with diverse sociodemo- graphic, cultural, and health or clinical characteristics, at one point in time.
Differences in the health problem experience across client populations or subgroups of the same target population have implications for the design of interventions, whereby different components are selected or their delivery is adapted or tailored to variations in the clients’ experience of the problem.
Results of descriptive longitudinal studies indicate changes in the experience, indicators, and severity levels of the health problem over time. Awareness of changes in the problem experience over time is informative as it guides the selection of the timing, within the health problem trajectory, for delivering the intervention; of the optimal dose at which the intervention is given which may incorporate “booster”
sessions to prevent relapse; and the organization or sequence with which the inter- vention components are offered.
Results of correlational cross-sectional studies support the existence, direction, and magnitude or size of the associations between the health problem, and its determinants. They shed light on the nature of the relationships (i.e. whether direct or indirect) between the problem and determinants. Findings of correlational longitudinal studies provide evidence of the sustainability or changes in the existence, direction, or magnitude of these relationships over time; they have the potential to identify the temporal sequence linking determinants to the problem, which is required to support naturally occurring causal linkages. For example, cross-sectional evidence has long supported the existence of a positive correlation between insomnia and depression; but it was not clear which of these two problems caused the other.
Recent longitudinal evidence suggests that insomnia predicts depression and that interventions addressing insomnia could contribute to improvement in depression and not the other way as implied in cross-sectional evidence (e.g. Fernandez-Men- doza et al., 2015).
Review of Qualitative Studies
Qualitative studies to include in the review are those that focused on exploring the experience of the health problem from the clients’ perspective. Clients are well known to hold implicit theories of the health problem; these theories reflect their personal construction of the problem and explanation of contributing factors (Arm- strong & Dregan, 2014). Qualitative studies using different approaches (e.g. phenom- enology, grounded theory) are selected if they aim to describe clients’ experience of the problem (e.g. indicators, impact on daily life); elucidate factors that contributed to the problem; or generate a theory or a model summarizing and explaining the intricate relationships among the determinants and the problem. Results of qualitative studies highlight the unique way in which the health problem is experienced by particular subgroups of the client population. They also assist in clarifying the pathway linking the determinants with the problem and in providing conceptual explanations of these associations.
Review of Reviews
Many types of literature reviews are useful in developing a comprehensive under- standing of the health problem. These are well described by Snilstveit et al. (2012), Paré et al. (2015), and Hong et al. (2017). Of interest to the generation of an
understanding of the health problem are reviews that synthesize theoretical or conceptual knowledge and quantitative and qualitative empirical evidence related to the problem experience and its associations with determinants.
Theoretical or conceptual reviews are exemplified with concept analysis (Hupcey
& Penrod, 2005) and framework synthesis (Carroll et al., 2013). Essentially, these consist of reviewing theoretical, empirical, and sometimes grey literature, for the purposes of: clarifying the attributes of the health problem; defining it at the theoret- ical and operational levels and distinguishing it from related concepts or problems;
and identifying its determinants.
Quantitative reviews include systematic reviews, meta-analyses, and umbrella reviews that focus on the relationships among determinants and the health prob- lems. The reviews apply a systematic process for searching the literature; identifying and selecting studies that meet the pre-specified criteria; appraising the study quality;
and extracting data on the existence, direction, and magnitude of the associations between the determinants and the problem. However, they differ in the method for synthesizing the evidence. Systematic reviews use vote count or content analysis to integrate evidence on the associations. Meta-analyses use statistical techniques to estimate the direction and magnitude of the association reported in each study; to determine the extent of variability in the estimates across studies. When the vari- ability is minimal, the estimates are synthesized to indicate the average level of asso- ciations between the problem and its determinants. Where there is high variability, statistical tests are used to identify conceptual and/or methodological factors that account for the observed variability in the estimates. Recently, umbrella reviews (also called reviews of reviews, meta-reviews or meta-evaluation/meta-epidemiology;
Gough et al., 2012) have been conducted to compare, contrast, reconcile, and/or explain differences in the results of systematic reviews and meta-analyses (Paré et al., 2015). Findings of systematic reviews, meta-analyses, and umbrella reviews indicate: the extent to which the associations between the determinants and the health problem exist within particular client populations and contexts, or are repli- cated across populations and settings; the expected direction and magnitude (or size) of the associations; and the factors that moderate the associations.
Qualitative Reviews
Meta-syntheses entail methods for integrating findings of qualitative studies (Edwards
& Kaimal, 2016) that investigated the health problem. Examples of methods include meta-ethnography and thematic synthesis that consist of searching the literature, identifying and selecting relevant studies, extracting and coding the findings of each study, then comparing and contrasting the codes to generate themes (Sandelowski &
Barraso, 2007; Snilstveit et al., 2012). The themes can provide a list of determinants and explanation of the inter-relationships among the determinants and the problem, embedded within or across contexts.
Mixed Reviews
Mixed reviews are increasingly performed to understand the health problem. They con- sist of integrating evidence synthesized from quantitative and qualitative studies. Mixed reviews are justified with the increasing complexity of the inter-relationships among determinants (occurring at different levels) and health problems (experienced in differ- ent domains), and the acknowledgement of the unique and complementary contribu- tion of quantitative and qualitative research methods (Edwards & Kaimal, 2016;
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Fleming, 2010; Hong et al., 2017). Mixed method reviews (e.g. critical interpretive syn- thesis) follow the same steps for searching the literature; identifying, selecting, and appraising quantitative and qualitative studies; and extracting data on the experience of the health problem and its determinants from each study. In some mixed-method reviews, the synthesis is conducted separately for the quantitative (e.g. through vote counting, estimating effect size) and the qualitative (e.g. coding, generating themes) findings; then, the synthesized quantitative and qualitative evidence is compared and contrasted to identify convergence and divergence. In other mixed-method reviews, the quantitative and qualitative data are integrated (i.e. brought together) during the anal- ysis and synthesis stages of the review.
The integration of the quantitative and qualitative evidence can be done by aggregation or configuration. Aggregation is used when quantitative and qualitative findings address the same association between a determinant and the health problem, and the purpose is to examine convergence (i.e. whether the findings con- firm each other). The aggregation may be accomplished at the data or study level.
Data-based aggregation involves the transformation of one type of data into another (e.g. quanticizing qualitative codes/themes) and analyzing the transformed data using the same analytic method (e.g. descriptive statistics). Study-based aggregation consists of juxtaposing the findings of quantitative and qualitative studies, using grids, tables or matrices, where the interface between the two types of findings occurs in the cells; the latter evidence is compared and contrasted to identify con- vergence (Fleming, 2010; Hong et al., 2017). Aggregation by configuration entails the arrangement of diverse findings into a coherent form or model. The quantitative and qualitative findings are carefully examined and analyzed to determine if they complement, extend, explain each other (e.g. why and how a determinant con- tribute to the health problem), or reflect variability in the problem experience and in the association of the determinant with the problem in different contexts (Sand- elowski et al., 2012).
All types of literature review are useful for understanding the health problem.
The mixed-method reviews are most promising in generating a comprehensive list of factors contributing to the problem, delineating direct and indirect relationships that are context-dependent, and providing explanation of why and how the determinants contribute to the health problem.
Methods
The process for conducting literature reviews is systematic. It has been extensively described in different sources (e.g. Heyvaert et al., 2016) as comprised of several steps. The steps are briefly reviewed with a particular emphasis on understanding the health problem.
1. Clarifying the health problem: This first step involves delineating the nature of the health problem and specifying the context (i.e. characteristics of the client population and context) of interest. This step is important for specifying the key words to be used in searching the literature and the criteria for selecting literature sources. The goal is to enhance relevance of the literature to the problem and context of interest.
2. Specifying the key words: The key words are the terms used to refer to the health problem. They include the specific words (e.g. insomnia) and its synonyms (e.g. sleep problem, disorder, difficulty) frequently appearing in the scientific literature and mentioned in lay conversation or documents. Consultation
with librarians is very helpful in finalizing the list of key words. The key words are used independently or in combination with other key words representing the target client population (e.g. older adults), context (e.g. primary care), and determinants of the problem (e.g. stress) if the determinants are known (e.g.
derived from pertinent middle range theories); alternatively, the terms
“factors,” “determinants,” “causes,” “predictors,” or similar ones are used in the initial search; and additional terms reflecting the specific factors identified through the review of the initial literature sources are used to refocus the search.
3. Conducting the search: The search for literature relevant to the experience and determinants of the health problem is carried out using multiple bibliographic databases pertaining to health literature in general or to specific health-related disciplines (e.g. CINAHL, MEDLINE, PSYCHINFO), for comprehensiveness.
The search may yield a large number of studies whose abstracts should be reviewed to determine their relevance. Setting reasonable limits to the search (e.g. language of publication and time period) enhances the relevance of the literature to the most recent conceptualization of the problem; further, the limits may render the review more focused and manageable.
4. Specifying the selection criteria: The criteria ensure the relevance of the litera- ture sources to be selected. As mentioned previously, theoretical or conceptual and empirical sources can be included in the review if they address any aspect of the health problem (e.g. presentation of its conceptual definition, descrip- tion of its indicators, and examination of its determinants). Quantitative and qualitative studies utilizing a range of research designs are sought, regardless of their quality. Quality is defined in terms of appropriately preventing or addressing biases that threaten validity of findings. Quality of the studies can be assessed with available tools and taken into account during the data anal- ysis and synthesis steps.
5. Identifying and selecting sources: Having a list of the preset selection criteria and clearly specified definitions and indicators of these criteria facilitates the review of the sources. The selection is done in two stages. First, the abstract of the identified source is read and its content evaluated for relevance (i.e.
meet all criteria). Second, copies of relevant sources are obtained for full review and, if considered to meet all preset criteria, are selected for inclusion in the literature review.
6. Extracting data: Selected sources are carefully reviewed to extract methodo- logical (e.g. type of design, sample size, study quality) and substantive (e.g.
conceptual and operational definitions of the problem and determinants investigated, target population, main findings related to the experience of the problem and its association with determinants). The data extracted are incor- porated in a database in preparation for synthesis of quantitative, qualitative, or both types of findings.
7. Synthesizing data: Different strategies and techniques can be used to syn- thesize descriptive and correlational (representing the reported associa- tions between determinants and the health problem) quantitative and qualitative findings, and to integrate quantitative and qualitative evidence (for detail, refer to Hong et al., 2017). The selection of a particular tech- nique is informed by the type of data extracted, the number of studies included in the review, and the availability of resources needed to apply the technique.
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The results of the literature review point to similarities or variations, across client populations, settings, and time occasions, in the experience of the health problem relative to its indicators and level of severity. They also identify the range of possible determinants and those most significant. They delineate the nature (direct or indirect);
direction (positive or negative); and size (small, moderate, large) of the relationships among determinants and the health problem experience. The findings, particularly those synthesized from qualitative studies and from theoretical sources, provide probable explanations (why and how) of the relationships. Table 3.3 illustrates the results of a narrative review of the literature on the determinants of insomnia.
Strengths
The advantages of literature reviews rest on grounding the understanding of the health problem on actual data obtained by multiple researchers, from different client populations under different contexts, using different designs and methods. Results that are consistent across populations, contexts, and research methods enhance the accuracy of the conceptualization of the problem. Comprehensive lists of indicators TABLE 3.3 Narrative review of literature on determinants of insomnia.
Category of
predictors Results Sources
Predisposing
factors Age: Older adults are prone to sleep disturbances (explanation: due to fragmented sleep or comorbid medical conditions)
Gender: Women of all age groups have a higher prevalence of sleep problems than men
Kao et al. (2008), López-Torres Hidalgo et al. (2012),
Paparrigopoulos et al. (2010), Rybarczyk et al. (2013), Singareddy et al. (2012), Zhang et al. (2012)
Precipitating
factors Comorbidity: Having one or more chronic diseases (e.g. cancer, angina, multiple sclerosis); symptoms (e.g.
pain); and sleep disorders (e.g.
restless leg syndrome), increases the odds of experiencing sleep problems Psychological conditions: depressive symptomatology and perceived distress
Social conditions: marital status, level of education and socioeconomic status
Dragiotti et al. (2018), Fernandez-Mendoza et al.
(2012), Gindin et al. (2014), López-Torres Hidalgo et al.
(2012), Rybarczyk et al. (2013) Gindin et al. (2014), Isaia et al.
(2011), Paparrigopoulos et al.
(2010), Pillai et al. (2014), Vgontzas et al. (2012).
Gellis et al. (2005), López- Torres Hidalgo et al. (2012), Moscou-Jackson et al. (2016) Perpetuating
factors Health behaviors: smoking, alcohol consumption, and limited
engagement in physical activity
Colagiuri et al. (2011), Endeshaw and Yoo (2010), Fernandez-Mendoza et al.
(2012), Paparrigopoulos et al.
(2010) Factors
identified by persons with insomnia
Worry, illness/discomfort
Note: varied by age such as worry more frequently reported in early working life and illness by older adults
Armstrong and Dregan (2014)
and determinants of the problem are generated, reflecting different but complemen- tary perspectives. These comprehensive lists reduce the likelihood of omitting a potentially significant indicator or determinant. The range of the severity level with which the problem is experienced by different client populations and in different contexts is identified. Factors contributing to different levels of problem severity may be revealed. Discrepancies in findings point to variability in the problem experience.
This empirical knowledge of the health problem is useful in directing the development of interventions and in identifying the need for tailoring the intervention to the char- acteristics of different client populations and contexts.
Limitations
The limitations of literature reviews relate to the (often limited) availability of well- planned and executed studies that investigated the health problem. Where available, there is the potential for publication bias (Chan et al., 2014), non-replication of find- ings, or having mixed or inconclusive findings, all of which weaken the confidence in the validity or accuracy of the generated knowledge, and hence its utility in inform- ing the design of interventions (Ioannidis et al., 2014: Van Assen et al., 2015).
3.3.2.2 Conduct of Primary Studies Overview
The decision to conduct a primary study to understand the health problem is made when: (1) there is a small number of studies that investigated the problem, thereby limiting the knowledge of the problem experience and its determinants; (2) the quality of available studies is appraised as low, which may be related to a range of conceptual and methodological concerns, such as unclear definition of the health problem, omission of theoretically important determinants, and use of measures with questionable reliability and validity; and (3) available studies have not investi- gated the health problem in the client population and context of interest, raising questions about the relevance and applicability of available evidence to the target population and context.
The primary studies can be prospective quantitative, qualitative, or mixed (quantitative and qualitative, concurrent, or sequential) method. Mixed-method studies are promising in generating a comprehensive, in-depth understanding of the problem as experienced by the target population in the particular context of interest.
Methods
The process for planning and conducting primary studies is well described in basic and advanced research textbooks, and is not reviewed here. However, some key con- siderations are briefly mentioned.
•
The main focus of the study is on the health problem and its determinants, as experienced by the target client population in the context of interest.•
The study is designed to address the specific gap in knowledge about the problem as experienced by the target client population and the context of interest.Quantitative, cross-sectional or longitudinal studies aim to: (1) describe the experience of the problem (e.g. frequency of occurrence, severity, most common indicators) and its determinants and consequences at one point in time, or changes in the problem experience and determinants over time;