Disclosure of complementary medicine use to medical providers: a systematic review and meta-analysis

Concomitant complementary medicine (CM) and conventional medicine use is frequent and carries potential risks. Yet, CM users frequently neglect to disclose CM use to medical providers. Our systematic review examines rates of and reasons for CM use disclosure to medical providers. Observational studies published 2003–2016 were searched (AMED, CINAHL, MEDLINE, PsycINFO). Eighty-six papers reporting disclosure rates and/or reasons for disclosure/non-disclosure of CM use to medical providers were reviewed. Fourteen were selected for meta-analysis of disclosure rates of biologically-based CM. Overall disclosure rates varied (7–80%). Meta-analysis revealed a 33% disclosure rate (95%CI: 24% to 43%) for biologically-based CM. Reasons for non-disclosure included lack of inquiry from medical providers, fear of provider disapproval, perception of disclosure as unimportant, belief providers lacked CM knowledge, lacking time, and belief CM was safe. Reasons for disclosure included inquiry from medical providers, belief providers would support CM use, belief disclosure was important for safety, and belief providers would give advice about CM. Disclosure appears to be influenced by the nature of patient-provider communication. However, inconsistent definitions of CM and lack of a standard measure for disclosure created substantial heterogeneity between studies. Disclosure of CM use to medical providers must be encouraged for safe, effective patient care.


Rationale:
Concomitant use of CM and conventional medicines can carry a variety of risks and benefits.
Effective communication between patients and providers is essential in order to ensure risks are minimised and benefits are optimised. Previous research from over a decade ago has shown that disclosure rates of CM use to conventional medical providers can vary widely and are often much lower than is desirable. The reasons patients give for not disclosing may offer insights into how disclosure rates might be improved. In order to identify whether or not disclosure rates are still lower than desired, and how communication about CM use between patients and providers might be optimised, a review of the current literature should be undertaken as an update on previous reviews of the topic.

Research Question:
To what extent do users of CM disclose this use to conventional medical providers, and what are their reasons for disclosing or not disclosing?

Objectives:
 To provide an update on the review by Robinson & McGrail (2004)  To assess rates of disclosure of CM use to conventional medical providers  To assess reasons for disclosing and not disclosing CM use to conventional medical providers  Manual search to be undertaken of reference lists from reviews identified during search, of reference lists from papers selected for review, and according to authors' expertise in topic. 3. Outcomes report rates of disclosure/non-disclosure and/or reasons for disclosure/non-disclosure of CM use to conventional health/medical practitioners.
4. CM defined as any service, product or practice outside of conventional/dominant medical system, whether self-prescribed or accessed through CM (non-conventional) practitioner.
5. Sample can be reasonably described as comprising members of the general population.
2. Sample cannot be reasonably described as comprising members of the general population (e.g. disease-specific population).

Additional Eligibility Criteria for Meta-Analysis:
With respect to homogeneity, additional criteria will be applied to identify those papers suitable for meta-analysis.
2. Disclosure rate well-defined and consistent between included studies.
3. Definition of CM or type of CM used consistent between included studies.
4. Acceptable score in risk of bias assessment.

Data Management:
Citations to be managed using EndNote (Clarivate Analytics) citation management software. A copy of the library is to be archived after each step of the selection process.

Selection Process:
Citations will be filtered first by assessing the paper's title, then by assessing abstract, in order to identify which papers require reading by full-text. Citations will be retained at each step if it is conceivable that the paper may meet eligibility criteria. Full text articles will then be screened against all inclusion/exclusion criteria. Selection of studies for meta-analysis will be undertaken after data extraction to identify those with sufficient homogeneity.
The filtering process will be undertaken by HF and overseen by AS, with a selected sample of eligible studies to be reviewed at each stage of screening. Discrepancies in opinion regarding which citations should be retained and which should be excluded will be resolved through discussion until consensus is reached.

Data Extraction:
A customised form will be used to systematically extract data from each retained full-text paper. This will include study characteristics (year, study design, location, setting, population, sample, funding sources) and details of disclosure/non-disclosure (rates, reasons), as well as space for additional disclosure-related data identified a posteriori.
Data extraction will be performed by HF and overseen by AS. Any data which is potentially relevant to the research question but does not explicitly fit within pre-defined variables will be discussed until consensus is reached in regards to its inclusion. Outcomes: