Do locally agreed guidelines for optometrists concerning the referral of glaucoma suspects influence referral practice?

Outcomes of newly referred patients with suspected angle closure: do we need to redefine the clinical pathways?

BACKGROUND/OBJECTIVES

To investigate outcomes of referrals for suspected angle closure and explore whether anterior segment optical coherence tomography (AS-OCT) can be used to tighten triaging criteria in a glaucoma virtual clinic.

SUBJECTS/METHODS

Retrospectively collected data. The first audit (04/2018-03/2019) identified referrals for suspected angle closure without other glaucoma-related findings (primary angle closure suspect (PACS) referrals). All patients underwent gonioscopy. The second audit (04-08/2019) identified patients with suspected angle closure in a virtual clinic. Management outcomes were assessed, using gonioscopy as reference standard. The outcomes of the second audit were re-audited after changing the triaging criterion from angle width <10° to iridotrabecular contact (ITC) in ≥1 quadrants on AS-OCT.

RESULTS

Out of 1754 glaucoma referrals (first audit), 24.6% (431/1754) were PACS referrals. Of these, only 10.7% (42/393) had an occludable angle on gonioscopy, with 97.6% (41/42) being PACS. Of these, 78% (32/41) underwent laser peripheral iridotomy. Out of 137 referrals in the virtual clinic (second audit), 66.4% (91/137) were triaged to the face-to-face clinic. Of these, 31.9% (29/91) were discharged. AS-OCT had positive and negative predictive value of 74.3% (95% confidence intervals (CI) 57.8-86.0) and 82.1% (95% CI 70.0-90.2%), respectively, in detecting ITC in ≥1 quadrants. In the re-audit 45.9% (45/98) of those with suspected angle closure were triaged for gonioscopy, with 24.4% (11/45) of them being discharged.

CONCLUSION

PACS referrals represent a substantial burden to hospital-based services and their accuracy is low. ITC in ≥1 quadrants on AS-OCT can be useful in triaging those who need further evaluation with gonioscopy.

Referrals from community optometrists in England and their replies: A mixed methods study

PURPOSE

Community optometrists, through routine eye examinations, identify patients with disease or ocular abnormalities requiring referral to the Hospital Eye Service. In many cases no reply to the referral letter is received, resulting in some patients being re-referred unnecessarily, potentially increasing the number of other patients who lose sight whilst on hospital waiting lists. This study investigated, qualitatively and quantitatively, factors influencing optometric referrals and replies.

METHODS

The three-phase, sequential mixed methods study started with a literature review and qualitative phase, interviewing stakeholders to identify issues for exploration in subsequent phases. The second, quantitative phase, undertook documentary analysis of 349 patient referral records from three optometric practice modalities (domiciliary, independently owned, and corporate chain) in England. A final qualitative phase obtained views from stakeholders to explore unexplained findings from the first two phases.

RESULTS

Phase 1 identified communication, financial, professional and technological issues for further exploration. In Phase 2, the referral rate was 22.2% for domiciliary provider, 2.1% for independent practice and 2.5% for the corporate chain, with the variation most likely explained by patient age and associated ophthalmic disease, illness and disability. The referral reply rate was 5.7% for domiciliary provider, 25.0% for independent practice and 4.9% for the corporate chain. The community optometrist remained unaware of the outcome of their referral in 72.8% of cases. Qualitative analyses indicate the main factors influencing referral reply rates are technology, the General Medical Practitioner, community optometrists' utility to and utility of the National Health Service and patient mobilisation.

CONCLUSIONS

The low referral reply rate creates a break in the feedback loop required to raise the standard of referrals and avoid unnecessary re-referral. Of the factors identified that influence referral reply rates, technology is key in view of the increasing use of online referral platforms. Feedback to the referring optometrist should be embedded in such systems.

Referrals from community optometrists to the hospital eye service in Scotland and England

Objectives

This audit assesses communication between community optometrists (COs) and hospital eye service (HES) in Scotland and England.

Methods

Optometric referrals and replies were extracted from six practices in Scotland and England. If no reply was found, replies/records were copied from HES records. De-identified referrals, replies and records were audited against established standards, evaluating whether referrals were necessary, accurate and directed to the appropriate professional. The referral rate (RR) and referral reply rate (RRR) were calculated.

Results

From 905 de-identified referrals, RR ranged from 2.6 to 8.7%. From COs’ perspective, the proportion of referrals for which they received replies ranged from 37 to 84% (Scotland) and 26 to 49% (England). A total of 88–96% of referrals (Scotland) and 63–76% (England) were seen in the HES. Adjusting for cases when it is reasonable to expect replies, RRR becomes 45–92% (Scotland) and 38–62% (England) with RRR significantly greater in Scotland (P = 0.015). Replies were copied to patients in 0–21% of cases. Referrals were to the appropriate service and judged necessary in ≥90% of cases in both jurisdictions. Accuracy of referral ranged from 89 to 97% (Scotland) and 81 to 98% (England). The reply addressed the reason for referral in 94–100% of cases (Scotland) and 93–97% (England) and was meaningful in 95–100% (Scotland) and 94–99% (England).

Conclusions

Despite the interdisciplinary joint statement on sharing patient information, this audit highlights variable standard of referrals and deficits in replies to the referring COs, with one exception in Scotland. Replies from HES to COs are important for patient care, benefitting patients and clinicians and minimising unnecessary HES appointments.

Knowledge translation for the everyday optometrist

A gap exists between best evidence and actual clinical care provided to patients. The advent of evidence-based practice was meant to address this gap by providing practitioners with a method to search, evaluate and incorporate evidence into practice. However, the gap continues to exist. The health research fields of knowledge translation and implementation science have evolved over the last few decades to assist practitioners in embedding research findings and best evidence into routine practice. Knowledge translation seeks to improve public health outcomes by facilitating the movement of best evidence from the bench to clinical practice. Implementation science is the study of methods to integrate research findings and evidence-based practice into routine practice. This literature review aims to revisit the concepts of evidence-based practice and to introduce knowledge translation and implementation science by exploring their roles and influences in the delivery of appropriate glaucoma care by optometrists.

Referrals from community optometrists to the hospital eye service in England

PURPOSE

In the UK, most referrals to the hospital eye service (HES) originate from community optometrists (CO). This audit investigates the quality of referrals, replies, and communication between CO and the HES.

METHODS

Optometric referrals and replies were extracted from three practices in England. If no reply letter was found, the records were searched at each local HES unit, and additional replies or records copied. De-identified referrals, replies and records were audited by a panel against established standards to evaluate whether the referrals were necessary, accurate and directed to the appropriate professional. The referral rate (RR) and referral reply rate (RRR) were calculated.

RESULTS

A total of 459 de-identified referrals were extracted. The RR ranged from 3.6%-8.7%. The proportion of referred patients who were seen in the HES unit was 63%-76%. From the CO perspective, the proportion of referrals for which they received replies ranged from 26%-49%. Adjusting the number of referrals for cases when it would be reasonable to expect an HES reply, RRR becomes 38%-62%. Patients received a copy of the reply in 3%-21% of cases. Referrals were made to the appropriate service in over 95% of cases, were judged necessary in 93%-97% and were accurate in 81%-98% of cases. The referral reply addressed the reason for the referral in 93%-97% and was meaningful in 94%-99% of cases. The most common conditions referred were glaucoma, cataract, anterior segment lesions, and neurological/ocular motor anomalies. The CO/HES dyad (pairing) in the area with the lowest average household income had the highest RR.

CONCLUSIONS

In contrast with the Royal College of Ophthalmologists/College of Optometrists joint statement on sharing patient information, CO referrals often do not elicit a reply to the referring CO. Replies from the HES to COs are important for patient care, benefitting patients and clinicians, and minimising unnecessary HES appointments.

Care pathways for glaucoma detection and monitoring in the UK

Glaucoma presents considerable challenges in providing clinically and cost-effective care pathways. While UK population screening is not seen as justifiable, arrangements for case finding have historically been considered relatively ineffective. Detection challenges include an undetected disease burden, whether from populations failing to access services or difficulties in delivering effective case-finding strategies, and a high false positive rate from referrals via traditional case finding pathways. The enhanced General Ophthalmic Service (GOS) in Scotland and locally commissioned glaucoma referral filtering services (GRFS) elsewhere have undoubtedly reduced false positive referrals, and there is emerging evidence of effectiveness of these pathways. At the same time, it is recognised that implementing GRFS does not intrinsically reduce the burden of undetected glaucoma and late presentation, and obvious challenges remain. In terms of diagnosis and monitoring, considerable growth in capacity remains essential, and non-medical health care professional (HCP) co-management and virtual clinics continue to be important solutions in offering requisite capacity. National guidelines, commissioning recommendations, and the Common Clinical Competency Framework have clarified requirements for such services, including recommendations on training and accreditation of HCPs. At the same time, the nature of consultant-delivered care and expectations on the glaucoma specialist's role has evolved alongside these developments. Despite progress in recent decades, given projected capacity requirements, further care pathways innovations appear mandated. While the timeline for implementing potential artificial intelligence innovations in streamlining care pathways is far from established, the glaucoma burden presents an expectation that such developments will need to be at the vanguard of future developments.

Accurate, fast, data efficient and interpretable glaucoma diagnosis with automated spatial analysis of the whole cup to disc profile

Background

Glaucoma is the leading cause of irreversible blindness worldwide. It is a heterogeneous group of conditions with a common optic neuropathy and associated loss of peripheral vision. Both over and under-diagnosis carry high costs in terms of healthcare spending and preventable blindness. The characteristic clinical feature of glaucoma is asymmetrical optic nerve rim narrowing, which is difficult for humans to quantify reliably. Strategies to improve and automate optic disc assessment are therefore needed to prevent sight loss.

Methods

We developed a novel glaucoma detection algorithm that segments and analyses colour photographs to quantify optic nerve rim consistency around the whole disc at 15-degree intervals. This provides a profile of the cup/disc ratio, in contrast to the vertical cup/disc ratio in common use. We introduce a spatial probabilistic model, to account for the optic nerve shape, we then use this model to derive a disc deformation index and a decision rule for glaucoma. We tested our algorithm on two separate image datasets (ORIGA and RIM-ONE).

Results

The spatial algorithm accurately distinguished glaucomatous and healthy discs on internal and external validation (AUROC 99.6% and 91.0% respectively). It achieves this using a dataset 100-times smaller than that required for deep learning algorithms, is flexible to the type of cup and disc segmentation (automated or semi-automated), utilises images with missing data, and is correlated with the disc size (p = 0.02) and the rim-to-disc at the narrowest rim (p<0.001, in external validation).

Discussion

The spatial probabilistic algorithm is highly accurate, highly data efficient and it extends to any imaging hardware in which the boundaries of cup and disc can be segmented, thus making the algorithm particularly applicable to research into disease mechanisms, and also glaucoma screening in low resource settings.

Prospective study of glaucoma referrals across Europe: are we using resources wisely?

BACKGROUND

To investigate the outcomes of glaucoma referrals across different European countries.

METHODS

250 patients newly referred to tertiary referral glaucoma specialist practices in the UK, Hungary, Slovenia, Italy and Greece were prospectively enrolled (50 consecutive patients per centre). Referral accuracy and predictive value of referral criteria for an intervention or further monitoring (positive predictive value) were analysed.

RESULTS

Same-day discharges occurred in 43% (95% CI 39% to 75%) (12/28) of optometrist-initiated referrals (UK only), 37% (95% CI 30% to 45%) (59/158) of ophthalmologist-initiated referrals (all centres) and 54% (95% CI 40% to 68%) (26/48) of self-referrals (Hungary, Italy and Greece). The percentages from all referral sources were 46% (95% CI 32% to 60%) in the UK, 56% (95% CI 44% to 70%) in Hungary, 30% (95% CI 17% to 43%) in Slovenia, 22% (95% CI 11% to 34%) in Italy and 60% (95% CI 46% to 74%) in Greece (p<0.001). Overall, the referring criterion was confirmed in 54% (95% CI 45% to 63%) (64/119) for intraocular pressure (IOP) >21 mm Hg, 56% (95% CI 43% to 69%) (33/59) for a suspicious optic disc and 61% (95% CI 45% to 77%) (22/36) for a suspicious visual field, with large between-country differences (p<0.05 for all comparisons). Of all referrals, 32% (95% CI 26% to 37%) were initiated on the basis of IOP >21 mm Hg only. By combining the IOP criterion with any other referring criterion, the positive predictive value increased from 56% (95% CI 45% to 67%) to at least 89% (95% CI 68% to 100%). In the UK, a hypothetical IOP threshold of >26 mm Hg, as a requirement for IOP-only referrals, would reduce IOP-only referrals by 44%, while not missing any definite glaucoma cases.

CONCLUSION

The accuracy of referrals was poor in the UK and the other countries. Requiring a combination of criteria and raising the IOP threshold for IOP-only referrals are needed to cut waste in clinical care.

Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)

BACKGROUND

Many glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.

OBJECTIVES

To assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.

DESIGN

Within-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.

SETTING

Secondary care.

PARTICIPANTS

Adults referred from the community to hospital eye services for possible glaucoma.

INTERVENTIONS

Heidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.

MAIN OUTCOME MEASURES

(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is 'discharge' or 'do not discharge'. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).

RESULTS

Data from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.

CONCLUSIONS

Automated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.

FUTURE WORK

There are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Factors influencing accuracy of referral and the likelihood of false positive referral by optometrists in Bradford, United Kingdom

AIMS

Levels of false positive referral to ophthalmology departments can be high. This study aimed to evaluate commonality between false positive referrals in order to find the factors which may influence referral accuracy.

METHODS

In 2007/08, a sample of 431 new Ophthalmology referrals from the catchment area of Bradford Royal Infirmary were retrospectively analysed.

RESULTS

The proportion of false positive referrals generated by optometrists decreases with experience at a rate of 6.2% per year since registration (p<0.0001). Community services which involved further investigation done by the optometrist before directly referring to the hospital were 2.7 times less likely to refer false positively than other referral formats (p=0.007). Male optometrists were about half as likely to generate a false positive referral than females (OR=0.51, p=0.008) and as multiple/corporate practices in the Bradford area employ less experienced and more female staff, independent practices generate about half the number of false positive referrals (OR=0.52, p=0.005).

CONCLUSIONS

Clinician experience has the greatest effect on referral accuracy although there is also a significant effect of gender with women tending to refer more false positives. This may be due to a different approach to patient care and possibly a greater sensitivity to litigation. The improved accuracy of community services (which often refer directly after further investigation) supports further growth of these schemes.

Patterns of adherence to NICE glaucoma guidance in two different service delivery models

PURPOSE

To assess adherence patterns to the UK National Institute of Health and Clinical Excellence (NICE) guidelines on glaucoma management (2009) in a tertiary referral centre shared care setting and in a district general hospital (DGH) setting.

METHOD

We performed a retrospective case note analysis of 200 patients from two centres between January and June 2010. The two centres involved were a consultant-guided teaching hospital optometry-led shared care setting (setting 1) and a consultant-led DGH clinic setting (setting 2). The main outcome measures were compliance with eight of the main NICE guidelines on glaucoma diagnosis and management (2009).

RESULTS

Both centres showed good adherence to the guidelines regarding the choice of initial treatment (96% vs 100%, settings 1 and 2, respectively) and arranging appropriate monitoring intervals (92% vs 86%). However, significant differences were seen when assessing whether an optic disc image was obtained at the initial visit (74% vs 10%), whether an appropriate initial assessment was performed (96% vs 58%), whether patients' review interval complied with the NICE guidance regardless of hospital cancellations (92% vs 66%), and whether concordance with medication was checked (88% vs 24%) (settings 1 and 2, respectively, P<0.01-Fisher's exact test).

CONCLUSION

Our study provides evidence to suggest that a hospital-based shared care service with trained optometrists using assessment sheets compares favourably to non-specialist glaucoma care delivered by ophthalmologists.

Comparison of optometrist glaucoma referrals against published guidelines

PURPOSE

To examine if community optometrists follow published guidelines for referral of patients with suspect glaucoma to the hospital eye service.

METHODS

A retrospective audit of new optometrist-initiated referrals to the Glaucoma Service at Moorfields Eye Hospital, London was performed. Clinical data from referral letters recorded included evidence of intraocular pressure (IOP) measurement and tonometer used. Referral letter information was compared to 2009 guidelines published jointly by the College of Optometrists and Royal College of Ophthalmologists on referring glaucoma suspect patients.

RESULTS

A total of 289 new patients were seen in the Glaucoma Service over a 6 week period from 4th January 2011; a 100% hospital record retrieval rate was obtained. Of these, 114 (39%) were optometrists initiated referrals. Optometrist letters were available for 105 patients. IOP measurements were recorded in 102 (97%); most practitioners used non-contact tonometry (NCT; n = 69; 68%). Practitioners recorded <4 NCT readings per eye (4 readings: n = 3, 4%; 3 readings: n = 42, 61%; 2 readings: n = 6, 9%; 1 reading: n = 18, 26%). Seventy-seven patients (73%) reported with raised IOP as the main referral reason; of these, 33 (43%) were referred with raised IOP in isolation. NCT was the instrument used in the majority of these raised IOP cases (n = 56; 73%). In cases where raised IOP in isolation was the referral reason, 24 (73%) were recorded using NCT; 10 (30%) provided repeat IOP measurement data in the letter. One hundred and two (97%) referred patients attended the hospital appointment. Thirty (29%) were deemed not to have glaucoma, with the remainder diagnosed with ocular hypertension (n = 25; 25%), glaucoma suspect/glaucoma (n = 35, 34%) or narrow angles requiring intervention (n = 12, 12%). Thirty of the 33 patients referred with raised IOP in isolation attended their hospital visit. Ten (33%) of these patients were subsequently discharged. Six (20%) patients had IOP within normal limits when measured with applanation tonometry; all of these patients were kept within the service.

CONCLUSIONS

Community optometrists using NCT for measurement should be reminded of the guidelines on number of readings to take and also the value of repeating NCT measures when appropriate. This may help to increase the accuracy of glaucoma suspect referrals to hospital eye service.

The Portsmouth-based glaucoma refinement scheme: a role for virtual clinics in the future?

BACKGROUND

Glaucoma referrals continue to impart a significant burden on Hospital Eye Services (HES), with a large proportion of these false positives.

AIMS

To evaluate the Portsmouth glaucoma scheme, utilising virtual clinics, digital technology, and community optometrists to streamline glaucoma referrals.

METHOD

The stages of the patient trail were mapped and, at each step of the process, 100 consecutive patient decisions were identified. The diagnostic outcomes of 50 consecutive patients referred from the refinement scheme to the HES were identified.

RESULTS

A total of 76% of 'glaucoma' referrals were suitable for the refinement scheme. Overall, 94% of disc images were gradeable in the virtual clinic. In all, 11% of patients 'attending' the virtual clinic were accepted into HES, with 89% being discharged for community follow-up. Of referrals accepted into HES, the positive predictive value (glaucoma/ocular hypertension/suspect) was 0.78 vs 0.37 in the predating 'unrefined' scheme (95% CI 0.65-0.87). The scheme has released 1400 clinic slots/year for HES, and has produced a £244 200/year cost saving for Portsmouth Hospitals' Trust.

CONCLUSION

The refinement scheme is streamlining referrals and increasing the positive predictive rate in the diagnosis of glaucoma, glaucoma suspect or ocular hypertension. This consultant-led practice-based commissioning scheme, if adopted widely, is likely to incur a significant cost saving while maintaining high quality of care within the NHS.

Glaucoma screening during regular optician visits: the feasibility and specificity of screening in real life

PURPOSE

To determine the feasibility and specificity of glaucoma screening during regular optician visits.

METHODS

In four optician shops, glaucoma screening was offered to 400 consecutive visitors aged 45 years or above. If the visitor agreed to participate, an intraocular pressure measurement and - in those with a pressure below 25 mmHg - a frequency-doubling perimeter (FDT) C20-1 visual field screening test were performed. Those with an elevated pressure or at least one reproducibly abnormal test location on FDT were referred to our hospital.

RESULTS

Three-hundred and fifty-two of 400 consecutive visitors (88%) were screened. Fifteen of the unscreened visitors were not screened because they were already regularly checked by an ophthalmologist related to glaucoma. Forty-two of 352 screened participants (12%) were referred. Of these 42 referrals, seven were diagnosed with glaucoma, 10 were diagnosed with ocular hypertension (OHT), 12 did not have any eye disease, seven had an eye disease other than glaucoma or OHT that was diagnosed previously and six were newly diagnosed with an eye disease other than glaucoma or OHT. The specificity of the screening protocol was 91% (95% confidence interval 88-94%).

CONCLUSIONS

Glaucoma screening at the optician shop was feasible, but the specificity of the screening protocol was rather low. With more stringent cut-off points (30 mmHg; at least two reproducibly abnormal test locations), the specificity could be improved to 96% (94-98%), apparently without a significant loss of sensitivity. This suggests that screening during regular optician visits might be a viable approach.

Assessment of referrals to the hospital eye service by optometrists and GPs in Bradford and Airedale

PURPOSE

To investigate the content of referrals to a hospital eye department and describe differences between referring clinician (optometrist or GP) and referral formats.

METHODS

A random sample of 433 new referrals to Bradford Royal Infirmary hospital eye service (HES) during 2007 and 2008 were retrospectively analysed.

RESULTS

Three hundred and eleven referrals (72%) were from optometric practice and 122 (28%) from general practice. Optometric referrals were mainly for cataract and posterior capsular opacification (27%), glaucoma or suspect glaucoma (20%) and diabetic retinopathy (10%).

CONCLUSIONS

The proportion of referrals to the hospital eye service from optometrists appears to be increasing (1988: 39%, 1999: 48%, present study 72%). GPs mainly refer patients with anterior segment disorders, particularly lid lesions, based on direct observation and symptoms. Optometrists refer patients with a wide range of ocular diseases and include fundus observations and visual acuity measurements in their referrals. There is a need to inform optometrists of what content is required in a referral to the HES from GOS sight tests, at least for the common referral conditions such as age-related cataract and suspect open-angle glaucoma. Referral forms specifically designed for these commonly referred conditions are likely to improve referral quality.

The Carmarthenshire Glaucoma Referral Refinement Scheme, a safe and efficient screening service

AIM

It has been previously shown that community refinement of glaucoma referrals is an efficient way to investigate and treat glaucoma suspects. The potential for false negatives has not been explored previously and we describe a scheme in which effort has been made to both assess and control for this, and report on its success.

METHODS

Trained optometrists were recruited to examine and investigate the patients referred with suspected glaucoma, with a view to decreasing false-positive rates in accordance with an agreed protocol. The randomly selected notes of 100 patients referred onward to the Hospital Eye Service (HES) by trained, accredited optometrists, and the notes and optic disc images of 100 randomly selected patients retained in the community were examined in order to determine the efficiency and safety of the scheme.

RESULTS

The scheme resulted in a 53% reduction in the total number of referrals to HES with a cost saving of £117 per patient. Analysis of patients referred resulted in a diagnosis of glaucoma or retention of patients in HES with suspected glaucoma in 83% and a good correlation between the hospital and optometric measurements. Analysis of notes and optic nerve images of patients not referred indicated no compromise on patient safety.

CONCLUSION

This study suggests that suspected glaucoma can be successfully refined in the community with benefits to both the patient and the hospital. We also suggest that such a scheme may be safe as well as cost-effective, a conclusion that has not as yet been reached by any other study.

The Peterborough scheme for community specialist optometrists in glaucoma: a feasibility study

PURPOSE

This study assessed the role of specialist optometrists who were working in the community and sharing the care for glaucoma patients with, and under close supervision of, a consultant ophthalmologist working in the Hospital Eye Services (HES) to ensure high-quality standards, safety, and care.

METHODS

From February 2005 onwards, the majority of all new glaucoma referrals to our eye department were diverted to our specialist optometrists in glaucoma (SOGs) in their own community practices. Selected patients in the HES setting who were already diagnosed with stable glaucoma were also transferred to the SOGs. The completed clinical finding details of the SOGs, including fundus photographs and Humphrey visual field tests, were scrutinised by the project lead.

RESULTS

This study included 1184 new patients seen by specialist optometrists between February 2005 and March 2007. A total of 32% of patients were referred on to the hospital, leaving the remaining 68% patients to be seen for at least their next consultation in the community by the SOGs. The following levels of disagreement were observed between SOGs and the project lead: on cup:disc ratio (11%), visual field interpretation (7%), diagnosis (12%), treatment plan (10%), and outcome (follow-up interval and location) (17%).

CONCLUSION

This study indicates that there is potential for a significant increase in the role of primary care optometry in glaucoma management. The study also confirms a need for a significant element of supervision and advice from a glaucoma specialist. The important issue of cost effectiveness is yet to be confirmed.

Can a community optometrist-based referral refinement scheme reduce false-positive glaucoma hospital referrals without compromising quality of care? The community and hospital allied network glaucoma evaluation scheme (CHANGES)

BACKGROUND/AIMS

To describe the design, activity, and quality of the referral refinement phase of a novel glaucoma shared-care scheme.

METHODS

Eight Optometrists with a Specialist Interest in glaucoma (OSI) were trained to perform a community-based comprehensive glaucoma evaluation of low-risk glaucoma hospital referrals (only one/none of the following factors noted for either eye: abnormal optic disc, abnormal visual field, abnormal intraocular pressure (IOP; 22-28 mmHg or IOP asymmetry)) using equipment standardized to that of the hospital glaucoma service.

RESULTS

One hundred and thirty-eight (27%) of a total of 512 glaucoma-related referrals were deemed 'low risk'. Their choice of OSI discharged 40 (35%). The consultant agreed (virtually) with the decision to discharge with 28 (70%) and disagreed with 12 (30%). Comparing findings between OSI and consultant for 99 referred patients, sensitivity, specificity, and negative predictive values for a suspicious optic disc were 78, 61, and 79%, respectively. For an IOP of >21 mmHg, they were 74, 85, and 90%, respectively. For an occludable anterior chamber angle (Van Herick's versus gonioscopy), they were 69, 88, and 94%, respectively.

CONCLUSION

This referral refinement process can reduce numbers of false-positive referrals attending the hospital glaucoma service while retaining a relatively high level of examination quality.

The quality of optometrists' referral letters for glaucoma

PURPOSE

The purpose of the study was to evaluate the quality of content of optometrist-initiated glaucoma referral letters arriving at the appointment booking centre at Moorfields Eye Hospital (MEH).

METHODS

The minimum standard of information required for an ophthalmologist to determine the appropriateness and urgency of glaucoma suspect referral was determined, and criteria for three standards of referral letter formulated: 'Ideal', 'Acceptable' and 'Fail'. These standards were applied to a prospective review of all optometrist-derived referrals for glaucoma or suspected glaucoma cases arriving in the MEH booking centre over a 4-month period. The contents of each letter were scrutinised and classified based on the criteria within each standard.

RESULTS

Forty-nine per cent of referral letters were found to be of 'acceptable' quality, 7%'ideal' quality and the remainder classed as "fail". The main reason for failure was an omission of non-clinical information, including patient and/or referring practice details, although 26% of letters failed to include an optic disc evaluation and 6% failed to provide intra-ocular pressure measurements. Two-thirds of 'acceptable' letters did not reach the 'ideal' standard due to a lack of discussion of risk factors, visual field analysis or recommendations for referral speed.

DISCUSSION

The information gleaned from this prospective study indicates a need to improve the quality of optometrists' glaucoma referral letters, particularly with respect to completion of all the items set out on the General Ophthalmic Services (GOS) 18 referral form.

The accuracy of accredited glaucoma optometrists in the diagnosis and treatment recommendation for glaucoma

AIM

To compare the diagnostic performance of accredited glaucoma optometrists (AGO) for both the diagnosis of glaucoma and the decision to treat with that of routine hospital eye care, against a reference standard of expert opinion (a consultant ophthalmologist with a special interest in glaucoma).

METHODS

A directly comparative, masked, performance study was undertaken in Grampian, Scotland. Of 165 people invited to participate, 100 (61%) were examined. People suspected of having glaucoma underwent, within one month, a full ophthalmic assessment in both a newly established community optometry led glaucoma management scheme and a consultant led hospital eye service.

RESULTS

Agreement between the AGO and the consultant ophthalmologist in diagnosing glaucoma was substantial (89%; kappa = 0.703, SE = 0.083). Agreement over the need for treatment was also substantial (88%; kappa = 0.716, SE = 0.076). The agreement between the trainee ophthalmologists and the consultant ophthalmologist in the diagnosis of glaucoma and treatment recommendation was moderate (83%, kappa = 0.541, SE = 0.098, SE = 0.98; and 81%, kappa = 0.553, SE = 0.90, respectively). The diagnostic accuracy of the optometrists in detecting glaucoma in this population was high for specificity (0.93 (95% confidence interval, 0.85 to 0.97)) but lower for sensitivity (0.76 (0.57 to 0.89)). Performance was similar when accuracy was assessed for treatment recommendation (sensitivity 0.73 (0.57 to 0.85); specificity 0.96 (0.88 to 0.99)). The differences in sensitivity and specificity between AGO and junior ophthalmologist were not statistically significant.

CONCLUSIONS

Community optometrists trained in glaucoma provided satisfactory decisions regarding diagnosis and initiation of treatment for glaucoma. With such additional training in glaucoma, optometrists are at least as accurate as junior ophthalmologists but some cases of glaucoma are missed.

An analysis of patients discharged from a hospital-based glaucoma case-finding clinic over a 3-year period

PURPOSE

To analyse the false positive referrals by community optometrists to a glaucoma case-finding clinic over a 3-year period.

METHODS

A retrospective study was undertaken of the 531 patients who were referred by community optometrists and discharged after their first visit to the glaucoma case-finding clinic at the Oxford Eye Hospital between 2003 and 2005. The number of patients who were referred on the basis of one, two or three abnormal parameters was determined. The specific reason why the presumed abnormal parameter was considered normal by a glaucoma specialist was determined from the patients' records.

RESULTS

The referral was based on only one presumed abnormal parameter in 65.5-74.3% of patients (minimum-maximum percentage per year, 2003-2005). Physiological cupping was present in 21.5-29.5%, asymmetrical cupping because of asymmetrical disc size in 6.4-8.2% and asymmetrical cupping in the presence of similar disc size in 1.9-5.1%. An intraocular pressure (IOP) within the normal range was measured in 17.6-20.8% and an IOP between 22 and 25 mmHg in association with a central corneal thickness of >588 microm was found in a further 11.5-15.4%. In 11.5-16.1% of patients who were referred because of an abnormal visual field, no field defect was found when the test was repeated. A cause other than glaucoma was responsible for an abnormal visual field defect in 1.2-6%.

CONCLUSION

This study identifies the factors responsible for false positive referrals to a hospital-based glaucoma case-finding clinic. By considering these factors and by combining test data, the number of unnecessary referrals could be reduced in the future.

ReGAE 2: glaucoma awareness and the primary eye-care service: some perceptions among African Caribbeans in Birmingham UK

AIMS

Investigations into glaucoma awareness have drawn on informed, clinic-based populations. The paper reports a section of findings from a larger study that aimed to elicit the perceptions of those potentially less informed in community settings.

METHODS

A qualitative investigation used face-to-face interviews and focus group discussions with 48 African Caribbean participants outside the hospital eye-service. Interview data were transcribed and coded using manual and computer-aided methods. Inferences and interpretations were corroborated by discussion with expert advisors and community members not directly involved in the study.

RESULTS

Positive attitudes to health promotion existed, but 'eye health' did not appear to be integral to individuals' health schemas. The capacity for primary eye care to enhance glaucoma knowledge appeared under utilised and inconsistent across modes of service delivery and was undermined by perceived conflicts of interest.

CONCLUSIONS

Enhancing reciprocal understanding between service users and ophthalmic practitioners in primary care is central to developing flexible, responsive local eye-care services. The study suggested useful foci for cultural self-reflection and self-awareness on the part of health professionals themselves, in relation to glaucoma detection. Areas for further research are identified.

The future of glaucoma clinics

The number of patients seen with glaucoma related pathologies is predicted to increase significantly over the next few years as a result of an ageing population, increased optometric screening, and raised public awareness. In addition, the recent glaucoma literature proposes more aggressive management of ocular hypertension, open angle glaucoma, and narrow angle pathologies. This will overburden many glaucoma services and demands a reappraisal of current management strategies. Using a database of patients compiled from their tertiary referral glaucoma service as an example, the authors discuss the current controversies relating to each glaucoma subtype, encompassing issues relating to disease prognosis, efficacy of treatment, and resource management. They also suggest a range of strategies aimed at streamlining glaucoma clinics. Examples include shared care schemes, multidisciplinary teams, clinic guidelines/protocols, and alteration of clinic review times. The predicted effect of such schemes on clinic workloads is discussed, together with any existing validation.

Glaucoma electronic patient record--design, experience and study of high-risk patients

AIM

To set-up a glaucoma electronic patient record (GEPR) and study referral details to a new glaucoma service, concentrating on high-risk patients.

METHOD

A GEPR was designed using the pre-existing hospital information technology (IT) infrastructure. Referral details of all new patients to the glaucoma service were completely electronically entered and analysed.

RESULTS

A GEPR was successfully established. A total of 402 referrals were studied. In all, 43% (40) of high-risk clinic patients (IOP>29 mmHg, or C/D ratio >0.8 or moderate to advanced visual field defects) had to wait longer than 8 weeks from GP referral to be seen at the glaucoma service. Of these, nine patients lost more than one line of Snellen's visual acuity attributable to glaucoma. The optometrist failed to document IOP in 17%, fundoscopy in 30%, and visual fields in 45% of all referrals.

CONCLUSIONS

A GEPR can be introduced in an NHS setting without disruption of clinical care and ophthalmic training, and facilitates detailed, accurate and rapid audit. Study of high-risk glaucoma referrals showed inadequate optometric referral details and poor prioritisation of urgent cases. This information is being utilised with the cooperation of local optometrists to refine the pattern of glaucoma referrals.

ReGAE 1: using the Shah–Cross model as an orientating framework in African-Caribbean glaucoma research

The inter-relationship between health-care research, policy and service development is convoluted and difficult to articulate. This paper describes a framework for planning research into a range of ophthalmic conditions differentially associated with specific ethnic groups. It discusses the utility of the 'Shah-Cross Model' in mapping development of a glaucoma research project, and communicating its implications for local eye-care policy and ophthalmic services directed towards detection and management of primary open-angle glaucoma in the African-Caribbean population in the UK.

Outcomes of referrals by community optometrists to a hospital glaucoma service

AIM

To determine the outcomes resulting from optometric referrals to a specialist glaucoma screening clinic over a 10 year period.

METHODS

Details of the initial clinical assessment of all new patients referred to the adult glaucoma screening clinic at Oxford Eye Hospital were collected prospectively from July 1994 to June 2004.

RESULTS

Optometrists working in community practice initiated 2505 referrals. Of these, glaucoma was confirmed in 510 patients (20.4%), including 160 with normal intraocular pressure (IOP). A diagnosis of ocular hypertension was made in 747 patients (29.8% of referrals) and 125 (5.0%) were categorised as glaucoma suspects. There was no evidence of a diagnostic trend over the period of data collection. Treatment to lower IOP was commenced in 458 patients (18.3%). Nearly half of those referred, 1148 (45.8%), were discharged from ophthalmological review at the first visit.

CONCLUSION

In this survey, the largest of its nature, only one in five subjects had glaucoma and nearly half were discharged from hospital ophthalmological review. The findings provide a baseline against which the effectiveness of any future system of glaucoma detection in the United Kingdom can be compared.

Screening for primary open-angle glaucoma in the developed world: are we there yet?

BACKGROUND

In 1995, the Quebec Agency for Health Services and Technology Assessment (AETMIS) stated that a formal screening program for primary open-angle glaucoma (POAG) could not be recommended for the province of Quebec, owing to "a high degree of uncertainty and because of the high cost such a program would entail." The purpose of this article was to evaluate the possibility of instituting a POAG screening program in light of recent advances in the diagnosis and treatment of glaucoma.

METHODS

We reviewed new developments that have occurred since the mid to late 1990s in the field of glaucoma. Changes that could positively influence the feasibility and organization of future glaucoma screening programs were identified.

RESULTS

New technologies, including confocal scanning laser ophthalmoscopy (HRT II), optical coherence tomography (Stratus OCT), and scanning laser polarimetry with variable corneal compensation (GDx-VCC), permit early detection of optic nerve and nerve fibre layer structural damage. Together with advanced psychophysical tests (frequency doubling perimetry and short wavelength automated perimetry) for earlier detection of functional damage, they provide an increased understanding of the diagnosis and monitoring of POAG. Elevated intraocular pressure (IOP) remains the most important risk factor for glaucoma. Clinical trials indicate that lowering IOP at different stages of the disease can arrest or decrease its rate of progression. Moreover, it is important to assess pachymetry because IOP measurements are influenced by central corneal thickness. Finally, new treatments, such as prostaglandin analogues or selective laser trabeculoplasty, are safer and may also achieve lower intraocular pressures.

INTERPRETATION

Health policy involves the investment of public resources, and cost-effectiveness analyses for POAG screening are heavily weighted by the degree of uncertainty that glaucoma screening can be effectively and reliably achieved. The many new developments and advancements outlined herein, combined with the possible increasing prevalence of POAG, necessitate the re-evaluation of screening for primary open-angle glaucoma.

Glaucoma detection in the community: does ongoing training of optometrists have a lasting effect?

PURPOSE

To establish whether the effect of improved glaucoma detection in the community suggested by an intervention study is maintained when intervention is extended to include all optometrists in the area.

METHODS

Optometrists' in the Ealing, Hammersmith, and Hounslow area were invited to ongoing training sessions following completion of an intervention study. The number of optometrist initiated referrals to Ealing Hospital Eye Clinic (EHEC) for suspect glaucoma was assessed over a 12-month period. The positive predictive value (PPV) of those referrals was calculated and a historical comparison made with the results of the original study.

RESULTS

A total of 376 new referrals for suspected glaucoma were assessed at EHEC during the 12-month period of data collection. This represents an increase in the number of referrals of 58% compared with an equivalent 12-month period during the initial intervention trial (376 vs. 238). The PPV was maintained at 0.45 (95% CI 0.41-0.51).

CONCLUSION

The rising number of new referrals for glaucoma together with maintenance of the PPV suggests an impact on the number of new cases of glaucoma detected in the community. The increase in referral numbers was limited to glaucoma when compared with new referrals for cataract. This implies a targeted effect of the intervention in terms of glaucoma detection. We believe the next step is to perform the study in an alternative location to see if the effect is repeatable elsewhere. If proven to be the case, there is a coherent argument for widespread adoption of this strategy to improve glaucoma case finding.

Evaluation of the high specificity Screening Program (C-20-1) of the Frequency Doubling Technology (FDT) perimeter in clinical practice

AIMS

To compare the efficacy of the high specificity Frequency Doubling Technology (FDT) Perimeter Screening Program (C-20-1) to standard threshold automated perimetry in the diagnosis of open-angle glaucoma.

METHODS

A total of 100 consecutively presenting patients attending a glaucoma clinic who volunteered for the study (approximately 30% of whom were attending for an initial visit) were examined with the FDT C-20-1 Screening Program and with the Humphrey Field Analyzer (HFA) SITA Fast algorithm and Program 24-2.

RESULTS

Of the patients, 17 were excluded due to unreliable visual field results or non-glaucomatous ocular abnormalities. In all, 10 patients were diagnosed as normal, 54 with open-angle glaucoma, eight with ocular hypertension, and 11 as glaucoma suspects. Of the 54 glaucomatous patients, 45 exhibited high-tension glaucoma and nine normal tension glaucoma. Perimetry with the HFA gave a sensitivity of 81.5% for the combined category of glaucoma and glaucoma suspect and a specificity of 83.3% for the combined category of normal and ocular hypertension. Perimetry with the FDT gave a sensitivity of 74.5% and a specificity of 85.2% compared to that of the HFA.

CONCLUSION

In the detection of glaucoma, Program C-20-1 of the FDT perimeter exhibits high specificity. It exhibits low sensitivity for the detection of mild loss but high sensitivity for advanced field loss relative to Program 24-2 and the SITA Fast algorithm of the HFA.

Glaucoma case finding: a cluster-randomised intervention trial

PURPOSE

To assess the effect of an intervention comprising training in optic disc assessment, explicit referral criteria and ophthalmologist feedback on referred patients, on the number of optometrist referrals for suspected glaucoma seen at a referral site and the positive predictive value of those referrals.

METHODS

Optometric practices routinely referring to the Ealing Hospital Eye Clinic were randomly divided into two groups taking into consideration those practices, which shared an optometrist (a cluster) and the number of optometrist days worked per week. One group of practices acted as controls, while the other practices were invited to receive the intervention. Data on 397 new patients referred and presenting to Ealing Hospital with suspected glaucoma were collected over a 20-month period. The data on patients who had failed to attend their appointment were collected over 7 months of this period. The number of referrals seen, the positive predictive value of those referrals, and the attendance rate were calculated. Optometrist's opinions of the intervention were assessed qualitatively. Data relating to optometrist compliance with the intervention were also collected.

RESULTS

The number of glaucoma referrals presenting to Ealing Hospital from the intervention practices was almost double that from the control practices (210 vs 119). When cluster randomisation, the number of optometrist days per cluster and the number of assessed referrals in the preintervention period are taken into consideration, it is estimated that the intervention is associated with a 52% increase in the number of referrals reaching Ealing Hospital. However, the design effect resulting from the cluster randomisation was unexpectedly high (of the order of 13-14)and so the confidence intervals around the estimate of 52% are very wide (95% c.i. 35% decrease to 253% increase, P = 0.34). There was no evidence of an association between optometrist compliance with the intervention and the number of referrals seen at Ealing Hospital. The positive predictive value (PPV)of referrals was similar for the intervention(0.49 (95% c.i. 0.42, 0.55)) and control groups(0.46 (95% c.i. 0.33, 0.60)). Optometrist opinions of the intervention were largely favourable. All expressed a willingness to participate in future programmes.

CONCLUSION

A large difference in the number of referrals between the practice groups was observed. Since the PPV of referral was unchanged, the potential impact of the intervention in terms of numbers of new cases of glaucoma detected in the community is substantial. However, because of its large design effect, this trial does not provide conclusive evidence of an impact of the intervention on referral numbers. A considerably larger trial will be required to produce conclusive evidence of an effect.

Initial management of ocular hypertension and primary open-angle glaucoma: an evaluation of the royal college of ophthalmologists' guidelines

PURPOSE

The purpose of this study was to identify any consensus of opinion among consultant ophthalmologists in Wales with respect to the initial management of glaucoma referrals based on the published guidelines of the Royal College of Ophthalmologists (RCO) and to compare consultant opinion with the practice in a typical hospital.

METHOD

The RCO guidelines document was studied to identify clear statements, which could be adopted as standards for audit purposes. A questionnaire was designed and sent to all consultant ophthalmologists in Wales (n=37) to obtain their opinions. An audit was performed of 100 consecutive patients referred to our unit as glaucoma suspects with regard to initial management. Descriptive statistical analysis was performed.

RESULTS

A good response rate for a postal questionnaire was obtained (81%) with 79.1% of responders finding the guidelines of at least some help. Levels of agreement with the definitions of ocular hypertension (OH) and primary open-angle glaucoma (POAG) were 76.7 and 86.7%, respectively. There was consensus of consultant opinion regarding many of the elements of the baseline clinical assessment with the significant exceptions of the necessity for dilated fundoscopy, gonioscopy, retinal nerve fibre layer assessment, and drawing of optic discs. The various 'clinical scenarios' for management of the RCO document were not all endorsed. The clinical audit results of the initial management of glaucoma referrals accurately reflected the consensus of the consultant opinion.

DISCUSSION

The RCO guidelines document represents a useful contribution to the management of patients with OH and POAG. Nevertheless, considerable variation in opinion exists concerning even the most basic areas. With the advent of clinical governance, bridging the gap between the conclusions of College working parties and realities of everyday practice will assume greater importance.

Community refinement of glaucoma referrals

AIM

To describe a Manchester-based glaucoma referral refinement scheme designed to reduce the number of false-positive referrals to the hospital eye service. To report on the first years results of this scheme and its financial costs to the NHS.

METHODS

Patients with suspected glaucoma, instead of being referred to their GP and then on to the hospital eye service, were referred to a group of specially trained community optometrists working to an agreed set of referral criteria. Those patients who did not meet the referral criteria were returned to the referring optometrist, while those who met the referral criteria were referred directly to Manchester Royal Eye Hospital. The patient's GP was informed in all cases.

RESULTS

The number of suspect glaucoma cases referred to the Manchester Royal Eye Hospital was reduced by 40%. This figure is close to the percentage of false-positive referrals measured at Manchester Royal Eye Hospital prior to the onset of this study. The information accompanying referral has been improved and the scheme produces a small financial cost saving to the NHS of approximately 17 pounds sterling per patient.

CONCLUSION

Community refinement of suspect glaucoma offers some important benefits over the current referral pathway.

Assessment of information included on the GOS 18 referral form used by optometrists

PURPOSE

To audit the information included on GOS 18 forms used by UK optometrists when referring patients to an ophthalmologist.

METHODS

All GOS 18 forms received in a hospital ophthalmology department over a 10-week period were photocopied and the categories of information presented were recorded.

RESULTS

A total of 444 forms were analysed. The two most common referral categories were cataract 36.7% (n = 163) and glaucoma 18.4% (n = 82). Only 7% (n = 11) of cataract referrals included details regarding effect on patient's lifestyle and willingness for surgery. Forty-seven per cent (n = 77) of referrals for cataract resulted in patients being listed for surgery. Eighty-two per cent (n = 67) of referrals for glaucoma included disc assessment, intraocular pressure and visual fields. Five per cent (n = 22) of optometrists gained the patients' consent for release of clinical information. Thirty-one per cent (n = 137) of forms had no practitioner name and 6% (n = 27) gave no practice address.

CONCLUSION

Information included on GOS 18 forms could be improved with regard to cataract referrals. Feedback from ophthalmologists would be facilitated by inclusion of practitioner/practice details, and by completion of the consent section on the GOS 18.

Practice guidelines and measurement: state-of-the-science

BACKGROUND

Restructuring of the health care system has exposed widespread evidence of practice variability and has highlighted the benefits associated with nurses embracing interdisciplinary, best practice solutions to health care delivery. Clinical practice guidelines have emerged as a valuable interdisciplinary evidenced-based tool.

PURPOSE

This article explores the state of the science of guideline measurement and evaluates the strengths and weaknesses of measurement approaches.

METHOD

A computerized search of Cumulative Index of Nursing and Allied Health Literature, Health and Psychosocial Instruments, Medline, and PubMed for the search term "practice guidelines" was combined with the following key words: attitudes, adherence, effect, impact, instrument, and measurement.

DISCUSSION

Measurement issues identified in this analysis are related to the manner in which guidelines are written and the lack of a standard methodology for measurement.

CONCLUSIONS

The challenge remains to establish sound measures of adherence and impact while controlling for confounding variables. Questions remain as to the format of practice guidelines to best grant autonomy while offering recommendations that are clear and measurable.