Diabetic Retinopathy Screening: A Systematic Review of Qualitative Literature

Screening for diabetic retinopathy with artificial intelligence: a real world evaluation

AIM

Periodic screening for diabetic retinopathy (DR) is effective for preventing blindness. Artificial intelligence (AI) systems could be useful for increasing the screening of DR in diabetic patients. The aim of this study was to compare the performance of the DAIRET system in detecting DR to that of ophthalmologists in a real-world setting.

METHODS

Fundus photography was performed with a nonmydriatic camera in 958 consecutive patients older than 18 years who were affected by diabetes and who were enrolled in the DR screening in the Diabetes and Endocrinology Unit and in the Eye Unit of ULSS8 Berica (Italy) between June 2022 and June 2023. All retinal images were evaluated by DAIRET, which is a machine learning algorithm based on AI. In addition, all the images obtained were analysed by an ophthalmologist who graded the images. The results obtained by DAIRET were compared with those obtained by the ophthalmologist.

RESULTS

We included 958 patients, but only 867 (90.5%) patients had retinal images sufficient for evaluation by a human grader. The sensitivity for detecting cases of moderate DR and above was 1 (100%), and the sensitivity for detecting cases of mild DR was 0.84 ± 0.03. The specificity of detecting the absence of DR was lower (0.59 ± 0.04) because of the high number of false-positives.

CONCLUSION

DAIRET showed an optimal sensitivity in detecting all cases of referable DR (moderate DR or above) compared with that of a human grader. On the other hand, the specificity of DAIRET was low because of the high number of false-positives, which limits its cost-effectiveness.

Diabetic Retinopathy: Clinical Features, Risk Factors, and Treatment Options

Diabetic retinopathy is a common complication of diabetes that affects the eyes and can lead to severe vision loss or blindness if left untreated. Chronic hyperglycemia destroys the blood vessels in the retina, resulting in diabetic retinopathy. The damage can lead to leakage of fluid and blood into the retina, causing edema, hemorrhages, and ischemia. A thorough evaluation by an ophthalmologist is necessary to determine the most appropriate course of treatment for each patient with diabetic retinopathy. The article discusses various surgical treatment options for diabetic retinopathy, including vitrectomy, scleral buckling, epiretinal membrane peeling, retinal detachment repair, and the risk factors of diabetic retinopathy. These surgical techniques can help to address the underlying causes of vision loss and prevent further complications from developing or worsening. To avoid complications and maintain vision, this review emphasizes the significance of early detection and treatment of diabetic retinopathy. Patients with diabetic retinopathy can improve their eyesight and quality of life with the help of some surgical treatments. The article also highlights some case studies in the field of diabetic retinopathy.

Feasibility and accuracy of the screening for diabetic retinopathy using a fundus camera and an artificial intelligence pre-evaluation application

AIMS

Periodical screening for diabetic retinopathy (DR) by an ophthalmologist is expensive and demanding. Automated DR image evaluation with Artificial Intelligence tools may represent a clinical and cost-effective alternative for the detection of retinopathy. We aimed to evaluate the accuracy and reliability of a machine learning algorithm.

METHODS

This was an observational diagnostic precision study that compared human grader classification with that of DAIRET®, an algorithm nested in an electronic medical record powered by Retmarker SA. Retinal images were taken from 637 consecutive patients attending a routine annual diabetic visit between June 2021 and February 2023. They were manually graded by an ophthalmologist following the International Clinical Diabetic Retinopathy Severity Scale and the results were compared with those of the AI responses. The main outcome measures were screening performance, such as sensitivity and specificity and diagnostic accuracy by 95% confidence intervals.

RESULTS

The rate of cases classified as ungradable was 1.2%, a figure consistent with the literature. DAIRET® sensitivity in the detection of cases of referable DR (moderate and above, "sight-threatening" forms of retinopathy) was equal to 1 (100%). The specificity, that is the true negative rate of absence of DR, was 80 ± 0.04.

CONCLUSIONS

DAIRET® achieved excellent sensitivity for referable retinopathy compared with that of human graders. This is undoubtedly the key finding of the study and translates into the certainty that no patient in need of the ophthalmologist is misdiagnosed as negative. It also had sufficient specificity to represent a cost-effective alternative to manual grade alone.

Factors Influencing Eye Screening Adherence Among Latinx Patients With Diabetes: A Qualitative Study

Purpose

Latinx populations have the highest rates of visual impairment and blindness of any ethnic group in the United States, with most cases of diabetic retinopathy remaining undiagnosed. We aimed to identify factors influencing adherence with diabetic eye screening in Latinx communities.

Methods

We conducted semistructured individual interviews with adult Latinx patients in Dane County, WI. Interviews were transcribed verbatim, translated from Spanish to English, and analyzed using QSR NVivo software. We performed both inductive open coding and deductive coding using the National Institute on Minority Health and Health Disparities Research Framework, as well as the Campbell and Egede Model.

Results

All participants (n = 20) self-identified as Latinx and were diagnosed with type 2 diabetes. The mean age was 61.5 years (range 33-79 years). Most participants were uninsured (60%), self-reported low or moderate health literacy (60%), and preferred to speak Spanish during their clinic appointments (75%). Individual-level barriers to diabetic eye screening included limited eye health literacy, lack of insurance coverage, and low self-efficacy with diabetes management. Health system-level facilitators included a recommendation to obtain eye screening from a primary care provider and the use of nonwritten forms of patient education. Community-level barriers included social isolation, concerns about inconveniencing others, machismo, and immigration status.

Conclusions

We identified several health system- and community-level factors, in addition to individual-level factors, influencing adherence with diabetic eye screening in Latinx communities.

Translational Relevance

Strategies addressing these factors may enhance the effectiveness of interventions to prevent blindness from diabetes and contribute to advancing health equity in Latinx communities.

Understanding the behavioral determinants that predict barriers and enablers of screening and treatment behaviors for diabetic retinopathy among Bangladeshi women: findings from a barrier analysis

BACKGROUND AND AIM

While early detection and timely treatments can prevent diabetic retinopathy (DR) related blindness, barriers to receiving these DR services may cause permanent sight loss. Despite having similar prevalence to diabetes and DR, women are less likely than men to perform these behaviors due to multi-faced barriers in screening and receiving follow-up treatments for DR. This study, therefore, aimed at identifying the barriers to - and enablers of - screening and follow-up treatments behaviors for DR among women aged more than 40 years with diabetes from the behavioral perspectives in Bangladesh.

METHODS

This Barrier Analysis study interviewed 360 women (180 "Doers" and 180 "Non-doers") to explore twelve behavioral determinants of four DR behaviors including screening, injection of anti-vascular endothelial growth factor (anti-VEGF medication), laser therapy and vitro-retinal surgery. The data analysis was performed to calculate estimated relative risk to identify the degree of association between the determinants and behaviors, and to find statistically significant differences (at p < 0.05) in the responses between the Doers and Non-doers.

RESULTS

Access to healthcare facilities was the major barrier impeding women from performing DR behaviors. Difficulty in locating DR service centers, the need to travel long distances, the inability to travel alone and during illness, challenges of paying for transportation and managing workload significantly affected women's ability to perform the behaviors. Other determinants included women's perceived self-efficacy, perceived negative consequences (e.g. fear and discomfort associated with injections or laser treatment), and cues for action. Significant perceived enablers included low cost of DR treatments, supportive attitudes by healthcare providers, government policy, and perceived social norms.

CONCLUSION

The study found a host of determinants related to the barriers to and enablers of DR screening and treatment behaviors. These determinants included perceived self-efficacy (and agency), positive and negative consequences, perceived access, perceived social norms, culture, and perceived risk. Further investments are required to enhance the availability of DR services within primary and secondary health institutions along with health behavior promotion to dispel misconceptions and fears related to DR treatments.

Examining the Role of Telemedicine in Diabetic Retinopathy

With the increasing prevalence of diabetic retinopathy (DR), screening is of the utmost importance to prevent vision loss for patients and reduce financial costs for the healthcare system. Unfortunately, it appears that the capacity of optometrists and ophthalmologists to adequately perform in-person screenings of DR will be insufficient within the coming years. Telemedicine offers the opportunity to expand access to screening while reducing the economic and temporal burden associated with current in-person protocols. The present literature review summarizes the latest developments in telemedicine for DR screening, considerations for stakeholders, barriers to implementation, and future directions in this area. As the role of telemedicine in DR screening continues to expand, further work will be necessary to continually optimize practices and improve long-term patient outcomes.

Clinical validation of a smartphone-based retinal camera for diabetic retinopathy screening

AIMS

This study aims to compare the performance of a handheld fundus camera (Eyer) and standard tabletop fundus cameras (Visucam 500, Visucam 540, and Canon CR-2) for diabetic retinopathy and diabetic macular edema screening.

METHODS

This was a multicenter, cross-sectional study that included images from 327 individuals with diabetes. The participants underwent pharmacological mydriasis and fundus photography in two fields (macula and optic disk centered) with both strategies. All images were acquired by trained healthcare professionals, de-identified, and graded independently by two masked ophthalmologists, with a third senior ophthalmologist adjudicating in discordant cases. The International Classification of Diabetic Retinopathy was used for grading, and demographic data, diabetic retinopathy classification, artifacts, and image quality were compared between devices. The tabletop senior ophthalmologist adjudication label was used as the ground truth for comparative analysis. A univariate and stepwise multivariate logistic regression was performed to determine the relationship of each independent factor in referable diabetic retinopathy.

RESULTS

The mean age of participants was 57.03 years (SD 16.82, 9-90 years), and the mean duration of diabetes was 16.35 years (SD 9.69, 1-60 years). Age (P = .005), diabetes duration (P = .004), body mass index (P = .005), and hypertension (P < .001) were statistically different between referable and non-referable patients. Multivariate logistic regression analysis revealed a positive association between male sex (OR 1.687) and hypertension (OR 3.603) with referable diabetic retinopathy. The agreement between devices for diabetic retinopathy classification was 73.18%, with a weighted kappa of 0.808 (almost perfect). The agreement for macular edema was 88.48%, with a kappa of 0.809 (almost perfect). For referable diabetic retinopathy, the agreement was 85.88%, with a kappa of 0.716 (substantial), sensitivity of 0.906, and specificity of 0.808. As for image quality, 84.02% of tabletop fundus camera images were gradable and 85.31% of the Eyer images were gradable.

CONCLUSIONS

Our study shows that the handheld retinal camera Eyer performed comparably to standard tabletop fundus cameras for diabetic retinopathy and macular edema screening. The high agreement with tabletop devices, portability, and low costs makes the handheld retinal camera a promising tool for increasing coverage of diabetic retinopathy screening programs, particularly in low-income countries. Early diagnosis and treatment have the potential to prevent avoidable blindness, and the present validation study brings evidence that supports its contribution to diabetic retinopathy early diagnosis and treatment.

Feasibility and Clinical Utility of Wide-Field Optical Coherence Tomography Angiography Compared to Ultrawide-Field Fluorescein Angiography in Patients with Diabetic Retinopathy

PURPOSE

To test the diagnostic performance of a novel wide-field swept-source optical coherence tomography angiography (WF-OCTA) device in detecting retinal non-perfusion (NP) and neovascularization (NV) in eyes with diabetic retinopathy (DR) and to compare this with the standard-of-care imaging method, ultrawide-field fluorescein angiography (UWFFA).

METHODS

Prospective, observational, cross-sectional single-center study evaluating patients with DR imaged with WF-OCTA (Xephilio OCT-S1; Canon Inc., Tokyo, Japan) and UWFFA (Optos California; Optos plc, Dunfermline, United Kingdom). WF-OCTA images of the superficial capillary plexus (SCP) consisted of single capture 23 × 20 mm scans centered on the fovea. In UWFFA and WF-OCTA, qualitative and quantitative measurements were assessed to analyze retinal NP and NV. Vessel density (VD) in WF-OCTA and ischemic index (ISI) in UWFFA were calculated. Qualitatively, the presence of NV and NP was assessed in both WF-OCTA (posterior pole/midperipheral retina) and UWFFA (posterior pole/midperipheral retina/far peripheral retina).

RESULTS

Ten consecutive patients with variable DR severity stages (17 eyes) were evaluated. Two eyes had to be excluded due to low quality of the WF-OCTA images. Therefore, 15 eyes were included for final analysis. Mean age was 57 years (± SD: 15.2) and the male : female ratio was 4 : 6. UWFFA identified retinal NP in 11 eyes (73%). Posterior pole NP was present in eight eyes, midperiphery NP was present in eight eyes, and far periphery NP was present in seven eyes. Retinal NV was detected in four eyes using UWFFA (two eyes with only midperiphery NV). WF-OCTA detected retinal NP in 11 eyes (9 cases with both posterior pole and midperiphery NP). NV was detected in three eyes (two with posterior pole and midperipheral NV, four with only midperipheral NV). Mean VD evaluated using WF-OCTA of the SCP was 0.40 (± SD: 0.1), and mean ISI in UWFFA was 0.09 (± SD: 1.3). Spearman's test did not show a significant correlation between the ISI in UWFFA and VD in WF-OCTA (p = 0.803).

CONCLUSIONS

Noninvasive WF-OCTA has great potential for the management of patients with DR. This new imaging modality might be useful in daily clinical routine in order to lower the number of invasive examinations. However, in a small percentage of patients, OCTA images cannot be reliably graded for the presence of NP and NV. In these cases, conventional FA needs to be performed.

Effectiveness of Nonmydriatic Ultra-Widefield Retinal Imaging to Screen for Diabetic Eye Disease: A Randomized Controlled Trial (Clearsight)

OBJECTIVE

Suboptimal diabetic eye disease screening is a major cause of preventable vision loss. Screening barriers include mydriasis and the need for dedicated screening appointments. The Clearsight trial assessed whether nonmydriatic ultra-widefield (NM UWF) screening on the day of a diabetes clinic visit improved detection of clinically important eye disease versus usual screening.

RESEARCH DESIGN AND METHODS

This single-center, randomized, parallel-group controlled trial was conducted at St. Joseph's Health Care, London, Ontario, Canada. Adults with diabetes due for screening were randomized to same-day, on-site screening (NM UWF imaging) on the day of a scheduled diabetes clinic visit or usual screening (encouraged to arrange optometrist screening). The primary outcome was detection of actionable eye disease (AED), defined as the need for an ophthalmology referral or increased ocular surveillance. The primary analysis (modified intention-to-screen) compared the proportions of AED between groups within 1 year of enrollment.

RESULTS

Of 740 participants randomized between 7 March 2016 and 17 April 2019, 335 on-site screening and 323 usual screening participants met criteria for the primary analysis. More AED was detected in the on-site screening group than in the usual screening group (50 of 335 [14.9%] vs. 22 of 323 [6.8%]; adjusted odds ratio 2.51; 95% CI 1.49-4.36). The number needed to screen by on-site screening in order to detect 1 additional patient with AED was 13 (95% CI 8-29).

CONCLUSIONS

Same-day, on-site screening by NM UWF imaging increased the detection of clinically important diabetic eye disease versus usual screening. Integration of NM UWF imaging into routine diabetes clinic visits improved screening adherence and has the potential to prevent vision loss.

Understanding barriers to diabetes eye screening in a large rural general practice: an audit of patients not reached by screening services

Introduction Diabetes is a leading cause of blindness in New Zealanders, yet a significant proportion of patients with diabetes are not reached by diabetes eye screening. Aim Our study audited patients with diabetes in a large New Zealand rural general practice, to identify addressable barriers preventing patients from attending diabetes eye screening. Methods All patients who had missed a diabetes eye screening appointment at the Dargaville Hospital Eye Screening Clinic between 2018 and 2021 were identified. Demographic information, laboratory and disease status data were recorded and analysed. Semi-structured telephone interviews were undertaken with 66 patients exploring barriers to diabetes eye screening. Descriptive statistical analysis was performed on quantitative data and a thematic analysis on qualitative results. Results One-hundred and fifty-four (27%) of 571 patients invited to screening missed at least one appointment; of these, 66 (43%) were interviewed. Quantitative analysis suggested Māori patients were less likely to be reached, with a 20% higher number of missed appointments than European patients and a higher glycated haemoglobin (HbA1c). Māori patients reported greater barriers to attending eye screening. Common barriers identified by participants were transport, work and family commitments, financial, health and lack of appointment reminders. Discussion Increased barriers for Māori patients could explain the reduced ability of the screening service to reach Māori patients. In order to address inequity and increase overall screening rates, diabetes eye screening and primary care services need to improve the booking system, facilitate transport to screening, engage patients and their whānau and build trust.

Improving Access to Eye Care: A Systematic Review of the Literature

PURPOSE

The goals were to develop a working and inclusive definition of access to eye care, identify gaps in the current system that preclude access, and highlight recommendations that have been identified in prior studies. This manuscript serves as a narrative summary of the literature.

CLINICAL RELEVANCE

Health care disparities continue to plague the nation's well-being, and eye care is no exception. Inequities in eye care negatively affect disease processes (i.e., glaucoma, cataracts, diabetic retinopathy), interventions (surgical treatment, prescription of glasses, referrals), and populations (gender, race and ethnicity, geography, age).

METHODS

A systematic review of the existing literature included all study designs, editorials, and opinion pieces and initially yielded nearly 2500 reports. To be included in full-text review, an article had to be US-based, be written in English, and address 1 or more of the key terms "barriers and facilitators to health care," "access," and "disparities in general and sub-specialty eye care." Both patient and health care professional perspectives were included. One hundred ninety-six reports met the inclusion criteria.

RESULTS

Four key themes regarding access to eye care from both patient and eye care professional perspectives emerged in the literature: (1) barriers and facilitators to access, (2) utilization, (3) compliance and adherence, and (4) recommendations to improve access. Common barriers and facilitators included many factors identified as social determinants of health (i.e., transportation, insurance, language, education). Utilization of eye care was largely attributable to having coverage for eye care, recommendations from primary care professionals, and improved health status. Geographic proximity, age, and lack of transportation surfaced as factors for compliance and adherence. There were a variety of recommendations to improve access to eye care, including improving presence in community health clinics, reimbursement for physicians, and funding of community-based programs such as DRIVE and REACH.

CONCLUSIONS

The eye care profession has abundant evidence of the disparities that continue to affect marginalized communities. Improving community-based programs and clinics, addressing social determinants of health, and acknowledging the effects of discrimination and bias on eye care serve as ways to improve equity in this field.

Artificial Intelligence-Based Teleopthalmology Application for Diagnosis of Diabetics Retinopathy

Diabetic Retinopathy (DR) is one of the leading causes of blindness for people who have diabetes in the world. However, early detection of this disease can essentially decrease its effects on the patient. The recent breakthroughs in technologies, including the use of smart health systems based on Artificial intelligence, IoT and Blockchain are trying to improve the early diagnosis and treatment of diabetic retinopathy. In this study, we presented an AI-based smart teleopthalmology application for diagnosis of diabetic retinopathy. The app has the ability to facilitate the analyses of eye fundus images via deep learning from the Kaggle database using Tensor Flow mathematical library. The app would be useful in promoting mHealth and timely treatment of diabetic retinopathy by clinicians. With the AI-based application presented in this paper, patients can easily get supports and physicians and researchers can also mine or predict data on diabetic retinopathy and reports generated could assist doctors to determine the level of severity of the disease among the people.

Assessment of sublingual microcirculation for the screening of diabetic nephropathy

OBJECTIVE

To investigate the potential of employing sublingual microcirculation as an early noninvasive screening technique for diabetic nephropathy (DN).

RESEARCH DESIGN AND METHODS

We recruited 89 patients with type 2 diabetes mellitus (T2DM) and 41 healthy subjects in this cross-sectional observational study. All participants underwent fluorescein fundus angiography, vibration perception testing, 10 g (Semmes-Weinstein) monofilament examination, nerve conduction velocity, and 24-h urine microalbumin determination. HbA1c, fasting plasma glucose, blood lipid, and estimated glomerular filtration rate(eGFR) were measured. Sublingual microcirculatory images were captured using side-stream dark-field (SDF) microcirculation microscopy, and total and perfused vascular density (TVD and PVD) were calculated.

RESULTS

The sublingual microcirculatory parameters denoting microvascular density and perfusion were negatively correlated with both fasting plasma glucose (TVD, r =  - 0.316, P < 0.001; PVD, r =  - 0.350, P < 0.001; PPV, r =  - 0.279, P = 0.001) and HbA1c (TVD, r =  - 0.367, P < 0.001; PVD, r =  - 0.423, P < 0.001; PPV, r =  - 0.399, P < 0.001). Diabetes patients already had a reduction in sublingual microcirculation compared with healthy control, and more severe reductions in TVD (7.07 ± 1.64 vs. 9.67 ± 1.94 mm/mm², P < 0.001) and PVD (5.88 ± 1.82 vs. 8.64 ± 2.46 mm/mm², P < 0.001) were found in those diabetes patients developed microvascular complications. Sublingual microcirculation impairment was accompanied with higher urinary albumin creatinine ratio (UACR). Receiver operating characteristic (ROC) analysis showed that TVD (area under the curve, AUC = 0.890 [0.836 0.944], P < 0.001) and PVD (AUC = 0.883 [0.826, 0.940], P < 0.001) could be indicators for DN screening. We derived a combined predictor index (CPI) considering both TVD and PVD for screening DN, and both the AUC (0.892, [0.838 0.945], P < 0.001) and cutoff point of 11.30 mm/mm² showed great improvement (sensitivity: 95.5%, specificity: 67.4%).

CONCLUSIONS

Diabetes patients experienced impaired sublingual microcirculation, which was closely correlated with UACR. Sublingual microcirculation monitoring could be used for the noninvasive early detection of DN.

Barriers and facilitators to diabetic retinopathy screening within Australian primary care

Background

Despite recent incentives through Medicare (Australia’s universal health insurance scheme) to increase retinal screening rates in primary care, comprehensive diabetic retinopathy (DR) screening has not been reached in Australia. The current study aimed to identify key factors affecting the delivery of diabetic retinopathy (DR) screening in Australian general practices.

Methods

A descriptive qualitative study involving in-depth interviews was carried out from November 2019 to March 2020. Using purposive snowballing sampling, 15 general practitioners (GPs) were recruited from urban and rural general practices in New South Wales and Western Australia. A semi-structured interview guide was used to collect data from participants. All interviews were conducted over the phone by one facilitator, and each interview lasted up to 45 min. The Socio-Ecological Model was used to inform the content of the interview topic guides and subsequent data analysis. Recorded data were transcribed verbatim, and thematic analysis was conducted to identify and classify recurrent themes.

Results

Of 15 GPs interviewed, 13 were male doctors, and the mean age was 54.7 ± 15.5 years. Seven participants were practising in urban areas, while eight were practising in regional or remote areas. All participants had access to a direct ophthalmoscope, but none owned retinal cameras. None of the participants reported performing DR screening. Only three participants were aware of the Medicare Benefits Schedule (MBS) items 12,325 and 12,326 that allow GPs to bill for retinal screening. Seven themes, a combination of facilitators and barriers, emerged from interviews with the GPs. Despite the strong belief in their role in managing chronic diseases, barriers such as costs of retinal cameras, time constraints, lack of skills to make DR diagnosis, and unawareness of Medicare incentives for non-mydriatic retinal photography made it difficult to conduct DR screening in general practice. However, several enabling strategies to deliver DR screening within primary care include increasing GPs’ access to continuing professional development, subsidising the cost of retinal cameras, and the need for a champion ace to take the responsibility of retinal photography.

Conclusion

This study identified essential areas at the system level that require addressing to promote the broader implementation of DR screening, in particular, a nationwide awareness campaign to maximise the use of MBS items, improve GPs’ competency, and subsidise costs of the retinal cameras for small and rural general practices.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01586-7.

Experiences of Patients With Diabetes Attending a Publicly Funded Eye Care Pathway in Western Sydney: A Qualitative Study

Diabetic retinopathy (DR) complications can be prevented with regular screening and timely access to an ophthalmologist for treatment. But there are patient and health system barriers that can impact access to DR services. This study aims to identify enablers and barriers for accessing public DR eye care services in a low socio-economic urban area of Australia. We conducted a qualitative study using semi-structured interviews for patients with diabetes aged 35 years and older attending public ophthalmology services. Interviews were analyzed to identify themes and subthemes; and the COM-B framework was used to interpret the complex behavioral mechanisms, including capability, opportunity, and motivation factors, to explain adherence to DR eye care. Three main themes and 7 sub-themes relating to patient experiences of DR care were derived. Patients were found to be passive actors in their DR eye care, but patients trusted clinicians and were determined to maintain their vision and quality of life. The barriers and facilitators of care related to the health system (service availability and recall–reminder systems) and patient experiences (choices, knowledge, and fear). The findings of this study will guide patient-centered initiatives to target and improve access to DR care. Strategies should focus on improving communication between eye care providers, and communication with patients to empower them to become more active players in healthcare decisions.