IIH Intervention: A Clinical Trial Comparing 2 Treatments (Shunts and Stents) Evaluation Of Clinical Effectiveness And Cost Effectiveness

Global thickness of the retinal nerve fibre layer (RNFL) over 6 months, as measured in micrometers by OCT

Global thickness of the retinal nerve fibre layer (RNFL) measured in micrometers by OCT over 12 and 24 months

Total retinal thickness measured in micrometers by OCT

Disc global volume measured in micrometers cubed by OCT

Disc central thickness measured by OCT (micrometers)

Disc maximum height measured by OCT (micrometers)

Macular ganglion cell layer volume as measured by OCT in micrometers cubed

Visual acuity, measured by logarithm of the minimum angle or resolution (LogMAR) units. Visual acuity (VA) is measured on the logMAR scale by sight tests in clinic using Early treatment diabetic retinopathy study (ETDRS) charts at 4 meters. Values are taken for each eye separately, both uncorrected, and corrected with glasses or contact lenses, and can range from 0, which represents perfect vision i.e. 20/20 (values of-0.1 and -0.2 are also possible representing better than perfect vision), to +2 which represents near blindness i.e. 20/2000. Increases in logMAR represent deterioration in vision.

Humphrey Visual Fields (HVF) 24-2 SITA standard visual field test measured by Perimetric Mean Deviation (PMD). Visual threshold is the intensity of stimulus seen 50% of the time at each location. Higher numbers mean the patient was able to see a more attenuated light, and thus has more sensitive vision at that location. The numerical total deviation map compares the patient's visual sensitivity to an average normal individual of the same age. It is useful to compare with age-matched normal thresholds as sensitivity normally decreases gradually with age. Positive values represent areas of the field where the patient can see dimmer stimuli than the average individual of that age. Negative values represent decreased sensitivity from normal. Reliability indices, including fixation losses, false positives, and false negatives are also included.

Proportion of patients re-presenting to hospital within 30 days post-intervention. Percentage

Proportion of patients being re-admitted to hospital within 30 days post-intervention. Percentage

Measured by the Clavien-Dindo classification of surgical complications. The Clavien-Dindo scale is a validated, 5-grade, ordinal scale used to grade surgical complications based on the therapeutic interventions required to manage them. It provides a standardised, objective method for reporting postoperative morbidity (grades I-IV) and mortality (grade V), with increasing severity based on the level of care, from minor bedside treatment to ICU-level support or death.

Measured by the Clavien-Dindo scale; grade I-II. The Clavien-Dindo scale is a validated, 5-grade, ordinal scale used to grade surgical complications based on the therapeutic interventions required to manage them. It provides a standardized, objective method for reporting postoperative morbidity (grades I-IV) and mortality (grade V), with increasing severity based on the level of care, from minor bedside treatment to ICU-level support or death.

Percentage

percentage

measured in days from day of intervention to day of first revision

number

CTCAE v5. In the CTCAE, symptoms are categorised by organ system, ranging from mild (Grade 1) to death (Grade 5)

number of days per month with headache reported

Measured by number of headache days per month with a severity greater than or equal to 4. 0-10 scale where 0 is no headache and 10 is the worst imaginable headache. Scores between 4 and 10 will be considered moderate to severe.

Headache severity measured by (numeric rating scale (NRS) 0-10) where 0 is no headache and 10 is the worst headache

Headache severity measured by (numeric rating scale (NRS) 0-10) where 0 is no headache and 10 is the worst headache. Moderate to severe headache severity (NRS greater than or equal to 4)

number of days per month where analgesics are used to treat headaches as documented on the concomitant medication form and the headache diary.

QoR 15 is a validated, 15-item patient-reported questionnaire used to measure the quality of recovery after surgery and anaesthesia, with a maximum score of 150 indicating excellent recovery.

5-point Likert scale with 1 - Very Unsatisfied and 5 - Very Satisfied

measure of visual function using a composite score ranging from 0-100, where higher scores indicate better function.

6-question tool that measures the impact of headaches on daily life, producing a total score between 36 and 78. Higher scores indicate greater severity. Scores of 60+ indicate a very severe, 56-59 a substantial, 50-55 some, and 49 or less little to no impact.

A patient-reported tool measuring eight health domains, scoring them from 0 to 100, where 0 represents maximum limitations and 100 represents no health restrictions

The EQ-5D-5L consists of 2 pages: the EQ-5D descriptive system and the EQ visual analogue scale (EQ VAS).

The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state.

The EQ VAS records the patient's self-rated health on a vertical visual analogue scale from 0 "worst imaginable health" to 100 "best imaginable health"

fewer days to return to work is better than more days to return to work

The WPAI measures absenteeism, presenteeism and activity impairment attributable to ill-health over the preceding 7 days.

The WPAI calculates percentage impairment (maximum 100%) with higher numbers representing greater work impairment.

Measured as a percentage of patients reporting use of ICP lowering medications

Designed to calculate how much healthcare resource is used by each patient since the last clinic visit. This assesses the economic impact of IIH and will record any major differences in cost per QALY gained on each arm of the trial