Objective assessment of compliance and persistence among patients treated for glaucoma and ocular hypertension: a systematic review

Methodological quality of the review: Low confidence

Author: Reardon G, Kotak S, Schwartz GF

Geographical coverage: Not reported

Sector: Glaucoma and ocular hypertension

Sub-sector: Compliance and persistence

Equity focus: None specified

Review type: Other review

Quantitative synthesis method: Narrative/thematic synthesis

Qualitative synthesis method: Not applicable

Background: Like other chronic diseases, unsuccessfully-controlled glaucoma may be preceded by ocular hypotension which is asymptomatic. Patients with glaucoma and ocular hypertension may be less motivated to maintain regular and continued use of their ocular hypotensive therapy. Also, the use of self-administered eye drops may further depress the motivation of these patients to comply and persist with therapy.

Motivating glaucoma patients to administer their drops would increase the effect of treatment. Therefore, it is important to investigate the association between compliance and glaucoma progression.

Objectives: The objectives were to update previous reviews measuring the magnitude of compliance or persistence problems in glaucoma with limiting the scope to objective assessments, stratify findings by measurement method used and to summarise findings by central tendency.

Main findings: 58 articles were included for measurement of compliance: electronic monitoring (seven studies reported in 14 articles), measurement of compliance/persistence–prescription records (36 studies in 38 articles), and measurement of persistence–medical chart review (six studies in six articles). According to the electronic monitoring, most therapy-experienced patients took medication consistently, but ≥20% met criteria for poor compliance. From prescription records, only 56% of the days in the first therapy year could be dosed with the medication supply dispensed over this period. At 12 months from therapy start, only 31% of new therapy users had not discontinued, and 40% had not discontinued or changed the initial therapy. From medical chart review, only 67% of patients remained persistent 12 months after starting therapy.

The authors concluded that poor compliance and persistence has been and remains a common problem for many glaucoma patients, especially for patients new to therapy. There is a need to understand the root causes and identification, and testing of solutions for this problem in the future research.

Methodology: Review authors used the PUBMED search tool to search for MEDLINE and other life science journals. The following search terms were used: compliance OR adherence OR adherent OR persistence OR persistency AND glaucoma OR ocular hypertension. Only studies published in English language journals from 1/1/1970 to 31/12/2010 were included.

Reference lists from eligible articles and literature reviews were also considered to identify potential titles. Titles were screened by one reviewer. Abstracts of potential topic-related studies were then reviewed. Only studies which reported original research findings for at least one objective assessment of compliance or persistence for patients receiving any ocular hypotensive agent were included. One reviewer reviewed the full text of included articles and summarised information in a table designed for data extraction.

The following types of studies were excluded from this review:

(a) Editorials, letters and other commentary pieces

(b) Narrative or clinical topic reviews

(c) Case studies

(d) Studies that had required failure on previous glaucoma therapy as an inclusion criterion for subject selection (thus containing an uncontrolled bias of regression to the mean)

(e) Interventional studies (such studies would typically not reflect usual care for glaucoma), unless a separate pre-interventional observation period was conducted for the entire patient sample (both study arms).

Studies that selected patients who were not new to ocular hypotensive therapy or who were required to meet some minimum threshold of persistence on therapy were not excluded from this review. However, such selection rules could have affected findings and are thus separately identified by study when employed.

Applicability/external validity: No methods were used either to assess the applicability/external validity of the results or to discuss how generalizable the results are

Geographic focus: Not specified.

Summary of quality assessment: Authors conducted a narrative synthesis of the findings, which seemed appropriate due to the vast differences of included studies. Authors appropriately reported inclusion/exclusion criteria used for study selection.

However, this review had some important limitations. The authors did not avoid publication and language bias in the search, only one relevant database was searched and only articles written in English were included in the review. Selection of relevant studies and data extraction was conducted by one reviewer. The quality and risk of bias of included studies were not discussed. Therefore, there is low confidence in the conclusions about the effects of this study.