Table 1.

Treatment adherence rates among patients with glaucoma

Study	Patient population	Study setting	Study design	N	Assessment technique	Study dates	Duration	Rate (%)
Loon et al32	Adult patients with chronic glaucoma who were receiving topical glaucoma therapy for >3 months	National university hospital in Singapore	Prospective, cross-sectional	314	RAM adherence questionnaire	NR	NR	19.7a
Rees et al33	Adult patients with glaucoma or ocular hypertension who had received ≥1 topical medication for ≥6 months	Tertiary referral ophthalmology hospitals in the US, Australia, and Singapore	Cross-sectional	475	Modified RAM adherence questionnaire	NR	NR	47.5–65.4b
Ung et al28	Adult patients with primary open-angle glaucoma, primary angle-closure glaucoma, exfoliative glaucoma, low-tension glaucoma, or who were suspected as having glaucoma >1 year who had filled a prescription for topical ocular hypertension medications	San Francisco General Hospital glaucoma clinic in the US	Retrospective, cross-sectional	126	Patient questionnaire	2011	1 year	50c
Vandenbroeck et al29	Adult patients with glaucoma or ocular hypertension who were receiving topical glaucoma medication	Hospital and private practice ophthalmology centers in Belgium	Multicenter, cross-sectional	663	Self-report questionnaire	NR	2 weeks	58.5d
Hong et al30	Adult patients with glaucoma	Medical university clinic in South Korea	Cross-sectional	125	Patient questionnaire	NR	NR	46.15–70.59e
Rees et al26	Adult patients with glaucoma or ocular hypertension who had received ≥1 topical medication for ≥6 months	Public tertiary ophthalmic hospital	Cross-sectional	131	Modified RAM adherence questionnaire	NR	2 months	55a
Djafari et al23	Adult patients with primary open-angle glaucoma, ocular hypertension, or who were suspected as having glaucoma for ≥2 years and were covered by the Régie d’Assurance Maladie du Québec pharmaceutical insurance program	Medicare database in Quebec, Canada	Descriptive database	181	Pharmaceutical claims database search	2004	1 year	71.8f
Olthoff et al31	Adult patients who were receiving treatment for primary open-angle glaucoma	the Netherlands	Cross-sectional	166	Patient questionnaire	NR	4 weeks	73.5d
Nordstrom et al18	Adult patients with confirmed or suspected open-angle glaucoma who received ≥1 topical ocular hypotensive medication and were continuously enrolled in the United Healthcare database for ≥365 days	Ingenix Research Database in the US	Retrospective cohort	5,300	Prescriptionrefill	1995–2001	36 months	15–58g
Sleath et al27	Adult patients with glaucoma who were receiving ≥2 IOP-lowering medications	Private ophthalmology clinics in the US	Cross-sectional survey	324	Patient questionnaire	2004	1 week	86h

Notes:

^aPatients who reported a full adherence score on the RAM questionnaire

^bpatients who disagreed or strongly disagreed in response to the questions “I sometimes forget to take my eye drops” and “I sometimes alter the dose or miss a dose of my eye drops to suit my own needs”, and who reported “never” in answer to the questions “Some people I have talked to say that they miss out on a dose of their eye drops or adjust the doses to suit their own needs. How often do you do that?” and “Sometimes people forget to take their eye drops. How often does this happen to you?”

^cpatients who reported >80% adherence in response to the question “We understand that many individuals who have been prescribed glaucoma medication find it very difficult to take them regularly and often miss doses. On a scale from 0 to 100, with 0% being you never take your medications to 100% being you always take your medications and never miss a dose, how often did you take your medications?”

^dpatients who reported no missed doses

^epatients who reported missing fewer than 1–2 doses per month

^fpatients who received ≥75% of their medication doses based on comparison of the number of days the patient had pharmaceutical coverage for medication versus the number of days the patient’s medical chart indicated medication was to be taken

^gpatients who had a current refill of their initially prescribed medication

^hpatients who reported taking 100% of their medication.

Abbreviations: IOP, intraocular pressure; NR, not reported; RAM, reported adherence to medication.