2.1 Search strategy

The search strategy was developed via Medline and adapted to the syntax of the other databases searched (Appendix 2). All searches were conducted through Medline, PubMed, CINAHL, Cochrane library, AMED, and Embase databases from 2000 to April 2023. Further studies were retrieved from backward manual searches of references listed in included studies. Additionally, PROSPERO was searched for any relevant, ongoing, or completed reviews of a similar nature.

2.2 Eligibility criteria

Both qualitative and quantitative studies were included with no study design or language limits imposed on the search. The study was limited to publications from the year 2000 onwards that included adults aged over 18 years with a diagnosis of CVI. Studies focusing on practitioner compliance and prescription rates, compression bandages only, other leg ulcers (e.g., diabetic or arterial) were not included.

2.3 Study selection

Following the database searches, initial literature results were uploaded to Covidence²⁸ to facilitate collaboration among reviewers. The title and abstract screening were performed independently by two authors (ES and MB), any conflicts were resolved via discussion between the two reviewers. Upon agreement of the initial screen, full-text extraction was conducted by two authors independently (ES and MB) against the inclusion/exclusion criteria listed above. Any discrepancies were resolved either by discussion between the two reviewers or by a third author (AC) until consensus was reached.

3.1 Study characteristics

The characteristics of the 14 studies included: primary author of the study, publication year, country, sample size, study design, and study aim (Table 2). Included are nine quantitative studies and five qualitative studies that were published between 2005 and 2023.

3.2 Study outcomes

The outcomes of the studies included: prescribing practitioner, type of compression therapy, compression class, compliance rates, and main reasons for non-compliance (Table 3). Of the included studies, 57% focused on the various stages of CVI,^29-35 29% focused on VLUs,^36-39 and 14% focused on VVs.^{40, 41} Compression class was only stated in 36% of the studies^{29, 31, 33, 36, 41} and type of compression garment used was only stated in 79% of the studies.^{29-33, 36-41} In 64% of the included studies, female was the predominant sex that participated.^{5, 29-32, 34, 36, 41, 42} One study did not record the sex.³⁹

The literature search revealed diverse reasons for non-compliance, with significant overlap between the studies. For this reason, the thematical interpretation of the results has been categorised into the five main overarching reasons for non-compliance, with emerging sub-themes. The main reasons for non-compliance to GCT are physical limitations, health literacy, discomfort, financial issues, and psychosocial issues.

4.1 Physical limitations

Each study in this review noted that physical limitations, leading to difficulty in garment application and removal, influenced compliancy. The application of a compression stocking requires a person to have the flexibility, coordination, strength, and dexterity to correctly and safely pull a garment on and off, and both age and obesity make this task extremely difficult, or impossible.⁴⁵

This analysis found that patients not only have application/removal difficulties, they also often require assistance, cannot reach their feet, have weak and painful hands, or they find it difficult to put footwear on with the garments in place.^{32, 36-38, 41}

Interestingly, none of the included studies mentioned an association between difficulty in application and age or body mass index (BMI). Six of the 14 studies noted that difficulty of garment application was one of the main reasons for non-compliance.^{29-31, 36, 37, 39} Interestingly, most of these studies involved patients with active ulcers, suggesting that difficulty in application may be related to the pain associated with a VLU and/or the requirement to apply a garment over a primary wound dressing.

4.2 Health literacy

Understanding the benefit of GCT and the progressive nature of CVI will influence compliance with prescription. Of the included studies, 10 mentioned lack of health literacy as a contributing factor to non-compliance.^{29, 32, 34-36, 38-41, 46} This included, but was not limited to, poor understanding as to why they need to wear GCT, a feeling the therapy is ineffective or unnecessary, a belief that CVI is not a serious disease, and a lack of understanding of the benefits of the therapy in general.

Health literacy is also a concern from the healthcare provider (HCP) perspective with some not prescribing GCT when indicated, and others failing to adequately explain the benefits and requirements of the prescription.^{32, 34-36, 38-40} One study found that there was a reduced prescription rate among GPs when GCT was warranted.³⁵ Participants in Dereure et al. (2005)'s study on compliance in patients with VLUs indicated that they felt GCT may in fact worsen their ulcer, perhaps indicating problems in the delivery of GCT education.³⁹ Both Gong et al. (2020) and Raju et al. (2007) included participants who were never recommended GCT by their HCP.^{32, 40}

Harker et al. (2000) found that patients want to understand as much information about their condition as possible, however, felt they were given inadequate information at times by their HCP, which can result in low compliance towards treatment.⁴⁷ Regarding the ineffectiveness of the therapy, it cannot be concluded if participants followed the HCP's instructions and adhered to the recommended time for an effect to occur or the benefits and timeframe were not thoroughly discussed by the HCP.

4.3 Discomfort

A variety of subjective terms were used by participants to describe reasons for non-compliance, which we have collectively classified as ‘discomfort’ for the purposes of this review. Discomfort included such terms as itchiness, heat, pain, worsening symptoms, skin issues, tightness, and incorrect fit. Poorly fitted GCT not only reduces the adequacy of compression to treat the disorder, possibly potentiating the CVI symptoms, it can lead to tightness, pain, and even tissue necrosis.⁴⁸ For this reason, it is important for a patient to have correct measurements taken of their limb to ensure the therapeutic and comfortable fit of a garment from a manufacturer with a wide range of sizes.

Despite the worsening of symptoms of CVI during hotter weather, there was no association found between climate and discomfort due to heat as a reason for non-compliance. For example, a Caribbean study found that sweating was only a minor reason (9.1%) for non-compliance.³¹ In the same instance in a Abidjan (West Africa) study heat was not a reason, however, the work environment was selected by 8.7% of participants and it was found that the participants who were less compliant due to work environment were working at multiple sites.³³ This may mean that being outdoors was more likely to contribute to over-heating from the garments and this may, in turn, lead to poorer compliance. Interestingly, studies conducted in France and Poland, where the climate is cooler compared to tropical regions, had heat, or sweating as one of the main reasons for non-compliance.^{35, 39, 41} Another way to interpret these results is that people in colder climates may have a lower heat tolerance compared to people living in warmer climates, and perhaps influencing compliance in different ways in different geographical regions.

4.4 Financial issues

The treatment and prevention of progression of CVI is continuous due to the chronic nature of the disorder. Once diagnosed, it is recommended that patients wear GCT long-term to prevent progression of the condition.⁴⁹ GCT needs to be replaced every 3–6 months due to the loss of elasticity (and therapeutic effect) of the garments due to normal wear and tear.⁵⁰ The retail price of GCT is variable across medical compression companies, particularly depending on the style, compression class, material, and size range of compression.

Participants in several studies documented that cost-to-purchase was one of the reasons they did not comply with their prescription.^{30, 32, 34-37, 40, 46} The two studies that indicated cost-to-purchase as one of the lowest contributing factors were both American studies.^{32, 37} Armstrong et al. (2017) reported that in the USA insurance companies often cover the costs of GCT, while in other international countries, the patient, regardless of health cover must cover the cost.⁵¹ In Australia, private health funds will cover up to 2–4 pairs per year.⁵² One Polish study of 16 770 participants indicated that 33% of the study population did not wear GCT due to the cost-to-purchase which was the main outcome of the study.³⁵ The thematic analysis of cost- to-purchase is likely to be skewed by the sociodemographic area that the research was conducted in.

4.5 Psychosocial issues

The psychosocial issues impacting compliance that were identified in the studies included a lack of self-discipline to wear the garments and their perceived unappealing nature. Five studies noted a lack of self-discipline as a reason for non-compliance.^{30, 32, 33, 37, 46} Patients simply did not want to wear them, could not be bothered to put them on, or did not prioritise the time for application.

Among the studies who found the garments to be aesthetically unappealing, female was the predominant sex within the participant population.^{29-32, 34, 42} This indicates a potential association between the female gender and unwillingness to wear GCT, since they are more likely to want to wear clothing that exposes the legs and feet, compared to the male population.