Abstract
Purpose :
Illness perceptions are feelings/beliefs patients have about their illness and are strongly associated with outcomes and adherence to treatment in chronic disease. Little is known about illness perception in open angle glaucoma (OAG) or ocular hypertension (OHT). We performed a cross-sectional case-control study using a validated instrument to examine aspects of illness perception in newly diagnosed people compared to patients who had been diagnosed for more than 2 years.
Methods :
119 participants were recruited from two clinical centres. Cases with OAG and OHT were recruited at the clinic visit when they received their diagnosis. An electronic patient record was used to find controls (OAG and OHT matched to cases by age and visual field loss) with a diagnosis for >2 years. The questionnaire was self-administered and incorporated the Brief Illness Perception Questionnaire (BIPQ), EQ5D Health and Type D Personality Scale (DS14). BIPQ measures illness representation and comprehension with 8 items measured on a visual analogue scale. Main outcome was differences in BIPQ items between cases and controls assessed by ANCOVA correcting for response to DS14.
Results :
Median (interquartile range) age and best eye Humphrey mean deviation for 27 OAG cases and 29 controls was 73 (66,78) yrs & -4 (-2,-7) dB and 66 (56,72) years & -3 (-1,-8) dB respectively. Median age for 30 OHT cases and 23 controls was 64 (54,70) years and 69 (60,75) yrs respectively. OAG patients with a diagnosis for >2 years (controls) reported worse illness perceptions compared to newly diagnosed cases in items on impact on life in general (p=0.01) and experience of symptoms (p=0.02). Controls claimed to understand their glaucoma better than newly diagnosed patients (p=0.01) and they better understood their diagnosis to be long-term (p=0.006). Newly diagnosed people with OHT reported worse illness perceptions compared to controls in items measuring effectiveness of treatment (p=0.002) and control over disease (p=0.03).
Conclusions :
Some illness perception measures differed between newly diagnosed people and patients living with their diagnosis for more than 2 years; the latter had a more realistic perception about symptoms and illness impact. Newly diagnosed people with OHT had noteworthy negative illness perceptions; these people might benefit from an intervention at diagnosis that highlights the positive prognosis for OHT.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.