Machine learning in primary care: potential to improve public health

It is estimated that missed opportunities for diagnosis occur in 1 in 20 primary care appointments. This is not only detrimental to individual patients, but also to the healthcare system as health outcomes are affected and healthcare expenditure inevitably increases. There are many potential solutions to limit the number of missed opportunities for diagnosis and management, one of which is through the use of artificial intelligence. Artificial intelligence and machine learning research and capabilities have exponentially grown in the past decades, with their applications in medicine showing great promise. As such, this review aims to discuss the possible uses of machine learning in primary care to maximise the quality of care provided.

Reliable, low-cost, fully integrated hydration sensors for monitoring and diagnosis of inflammatory skin diseases in any environment

Present-day dermatological diagnostic tools are expensive, time-consuming, require substantial operational expertise, and typically probe only the superficial layers of skin (~15 μm). We introduce a soft, battery-free, noninvasive, reusable skin hydration sensor (SHS) adherable to most of the body surface. The platform measures volumetric water content (up to ~1 mm in depth) and wirelessly transmits data to any near-field communication-compatible smartphone. The SHS is readily manufacturable, comprises unique powering and encapsulation strategies, and achieves high measurement precision (±5% volumetric water content) and resolution (±0.015°C skin surface temperature). Validation on n = 16 healthy/normal human participants reveals an average skin water content of ~63% across multiple body locations. Pilot studies on patients with atopic dermatitis (AD), psoriasis, urticaria, xerosis cutis, and rosacea highlight the diagnostic capability of the SHS (P _AD = 0.0034) and its ability to study impact of topical treatments on skin diseases.

Diagnosis of Skin Lesions Using Photographs Taken With a Mobile Phone: An Online Survey of Primary Care Physicians

Skin conditions are one of the most frequent reasons for visiting a primary health care facility, making it of vital importance that general practitioners (GPs) have the right knowledge and tools to diagnose the most frequent dermatological conditions. Methods: This study evaluates the accuracy of dermatological diagnoses made by 120 GPs based on photographs taken with a smartphone by an anonymous online cross-sectional survey. Results: The study was carried out between August and October 2018. The results show that the majority of the participants are in favor of using mobile phones to communicate with other professionals and use them to consult medical images. The majority (69%) took dermatological photographs and the preferred device was a smartphone (70%). From 22 different images evaluated, in 69% of responses, participants expressed a high degree of confidence in their ability to diagnose the lesion shown and in 72% of the cases, the diagnosis chosen was correct. Conclusions: The study confirms that the use of smartphone to send medical images is growing rapidly and its potential for taking medical images is an opportunity to help primary care teams deal with dermatological problems. The results suggest that GPs need further training in interpreting dermatological images, to increase their diagnostic confidence and to avoid the need for referrals to face-to-face visits.

Visual inspection for diagnosing cutaneous melanoma in adults

BACKGROUND

Melanoma has one of the fastest rising incidence rates of any cancer. It accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. History-taking and visual inspection of a suspicious lesion by a clinician is usually the first in a series of 'tests' to diagnose skin cancer. Establishing the accuracy of visual inspection alone is critical to understating the potential contribution of additional tests to assist in the diagnosis of melanoma.

OBJECTIVES

To determine the diagnostic accuracy of visual inspection for the detection of cutaneous invasive melanoma and atypical intraepidermal melanocytic variants in adults with limited prior testing and in those referred for further evaluation of a suspicious lesion. Studies were separated according to whether the diagnosis was recorded face-to-face (in-person) or based on remote (image-based) assessment.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: CENTRAL; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Test accuracy studies of any design that evaluated visual inspection in adults with lesions suspicious for melanoma, compared with a reference standard of either histological confirmation or clinical follow-up. We excluded studies reporting data for 'clinical diagnosis' where dermoscopy may or may not have been used.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated summary sensitivities and specificities per algorithm and threshold using the bivariate hierarchical model. We investigated the impact of: in-person test interpretation; use of a purposely developed algorithm to assist diagnosis; and observer expertise.

MAIN RESULTS

We included 49 publications reporting on a total of 51 study cohorts with 34,351 lesions (including 2499 cases), providing 134 datasets for visual inspection. Across almost all study quality domains, the majority of study reports provided insufficient information to allow us to judge the risk of bias, while in three of four domains that we assessed we scored concerns regarding applicability of study findings as 'high'. Selective participant recruitment, lack of detail regarding the threshold for deciding on a positive test result, and lack of detail on observer expertise were particularly problematic.Attempts to analyse studies by degree of prior testing were hampered by a lack of relevant information and by the restricted inclusion of lesions selected for biopsy or excision. Accuracy was generally much higher for in-person diagnosis compared to image-based evaluations (relative diagnostic odds ratio of 8.54, 95% CI 2.89 to 25.3, P < 0.001). Meta-analysis of in-person evaluations that could be clearly placed on the clinical pathway showed a general trade-off between sensitivity and specificity, with the highest sensitivity (92.4%, 95% CI 26.2% to 99.8%) and lowest specificity (79.7%, 95% CI 73.7% to 84.7%) observed in participants with limited prior testing (n = 3 datasets). Summary sensitivities were lower for those referred for specialist assessment but with much higher specificities (e.g. sensitivity 76.7%, 95% CI 61.7% to 87.1%) and specificity 95.7%, 95% CI 89.7% to 98.3%) for lesions selected for excision, n = 8 datasets). These differences may be related to differences in the spectrum of included lesions, differences in the definition of a positive test result, or to variations in observer expertise. We did not find clear evidence that accuracy is improved by the use of any algorithm to assist diagnosis in all settings. Attempts to examine the effect of observer expertise in melanoma diagnosis were hindered due to poor reporting.

AUTHORS' CONCLUSIONS

Visual inspection is a fundamental component of the assessment of a suspicious skin lesion; however, the evidence suggests that melanomas will be missed if visual inspection is used on its own. The evidence to support its accuracy in the range of settings in which it is used is flawed and very poorly reported. Although published algorithms do not appear to improve accuracy, there is insufficient evidence to suggest that the 'no algorithm' approach should be preferred in all settings. Despite the volume of research evaluating visual inspection, further prospective evaluation of the potential added value of using established algorithms according to the prior testing or diagnostic difficulty of lesions may be warranted.

Visual inspection and dermoscopy, alone or in combination, for diagnosing keratinocyte skin cancers in adults

BACKGROUND

Early accurate detection of all skin cancer types is important to guide appropriate management, to reduce morbidity and to improve survival. Basal cell carcinoma (BCC) is almost always a localised skin cancer with potential to infiltrate and damage surrounding tissue, whereas a minority of cutaneous squamous cell carcinomas (cSCCs) and invasive melanomas are higher-risk skin cancers with the potential to metastasise and cause death. Dermoscopy has become an important tool to assist specialist clinicians in the diagnosis of melanoma, and is increasingly used in primary-care settings. Dermoscopy is a precision-built handheld illuminated magnifier that allows more detailed examination of the skin down to the level of the superficial dermis. Establishing the value of dermoscopy over and above visual inspection for the diagnosis of BCC or cSCC in primary- and secondary-care settings is critical to understanding its potential contribution to appropriate skin cancer triage, including referral of higher-risk cancers to secondary care, the identification of low-risk skin cancers that might be treated in primary care and to provide reassurance to those with benign skin lesions who can be safely discharged.

OBJECTIVES

To determine the diagnostic accuracy of visual inspection and dermoscopy, alone or in combination, for the detection of (a) BCC and (b) cSCC, in adults. We separated studies according to whether the diagnosis was recorded face-to-face (in person) or based on remote (image-based) assessment.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Studies of any design that evaluated visual inspection or dermoscopy or both in adults with lesions suspicious for skin cancer, compared with a reference standard of either histological confirmation or clinical follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic thresholds were missing. We estimated accuracy using hierarchical summary ROC methods. We undertook analysis of studies allowing direct comparison between tests. To facilitate interpretation of results, we computed values of sensitivity at the point on the SROC curve with 80% fixed specificity and values of specificity with 80% fixed sensitivity. We investigated the impact of in-person test interpretation; use of a purposely-developed algorithm to assist diagnosis; and observer expertise.

MAIN RESULTS

We included 24 publications reporting on 24 study cohorts, providing 27 visual inspection datasets (8805 lesions; 2579 malignancies) and 33 dermoscopy datasets (6855 lesions; 1444 malignancies). The risk of bias was mainly low for the index test (for dermoscopy evaluations) and reference standard domains, particularly for in-person evaluations, and high or unclear for participant selection, application of the index test for visual inspection and for participant flow and timing. We scored concerns about the applicability of study findings as of 'high' or 'unclear' concern for almost all studies across all domains assessed. Selective participant recruitment, lack of reproducibility of diagnostic thresholds and lack of detail on observer expertise were particularly problematic.The detection of BCC was reported in 28 datasets; 15 on an in-person basis and 13 image-based. Analysis of studies by prior testing of participants and according to observer expertise was not possible due to lack of data. Studies were primarily conducted in participants referred for specialist assessment of lesions with available histological classification. We found no clear differences in accuracy between dermoscopy studies undertaken in person and those which evaluated images. The lack of effect observed may be due to other sources of heterogeneity, including variations in the types of skin lesion studied, in dermatoscopes used, or in the use of algorithms and varying thresholds for deciding on a positive test result.Meta-analysis found in-person evaluations of dermoscopy (7 evaluations; 4683 lesions and 363 BCCs) to be more accurate than visual inspection alone for the detection of BCC (8 evaluations; 7017 lesions and 1586 BCCs), with a relative diagnostic odds ratio (RDOR) of 8.2 (95% confidence interval (CI) 3.5 to 19.3; P < 0.001). This corresponds to predicted differences in sensitivity of 14% (93% versus 79%) at a fixed specificity of 80% and predicted differences in specificity of 22% (99% versus 77%) at a fixed sensitivity of 80%. We observed very similar results for the image-based evaluations.When applied to a hypothetical population of 1000 lesions, of which 170 are BCC (based on median BCC prevalence across studies), an increased sensitivity of 14% from dermoscopy would lead to 24 fewer BCCs missed, assuming 166 false positive results from both tests. A 22% increase in specificity from dermoscopy with sensitivity fixed at 80% would result in 183 fewer unnecessary excisions, assuming 34 BCCs missed for both tests. There was not enough evidence to assess the use of algorithms or structured checklists for either visual inspection or dermoscopy.Insufficient data were available to draw conclusions on the accuracy of either test for the detection of cSCCs.

AUTHORS' CONCLUSIONS

Dermoscopy may be a valuable tool for the diagnosis of BCC as an adjunct to visual inspection of a suspicious skin lesion following a thorough history-taking including assessment of risk factors for keratinocyte cancer. The evidence primarily comes from secondary-care (referred) populations and populations with pigmented lesions or mixed lesion types. There is no clear evidence supporting the use of currently-available formal algorithms to assist dermoscopy diagnosis.

Dedicated general practitioner education sessions can improve diagnostic capabilities and may have a positive effect on referral patterns for common skin lesions

INTRODUCTION

General practitioners (GPs) require the necessary skills to identify potentially malignant skin lesions and refer patients in an appropriate and timely manner. We examined the impact of a single consultant delivered education session to GP trainees on their diagnosis of common skin lesions.

METHODS

A prospective analysis of baseline knowledge was assessed using a photographic questionnaire. A dedicated education session was delivered by a consultant plastic surgeon. Their knowledge was re-assessed after 3 months.

RESULTS

There were 23 participants. Baseline ability to correctly diagnose skin lesions improved significantly at 3 months following dedicated teaching (baseline mean 30.2%, 3-month mean 65.9%, p = 0.001). All trainees recommended that dedicated skin education should be incorporated into GP training curricula.

CONCLUSION

Dedicated education sessions on skin lesions can improve the diagnostic accuracy of GP trainees, and we suggest that they are incorporated into the GP training curriculum.

Potential effect of patient-assisted teledermatology on outpatient referral rates

We carried out a pilot study on the feasibility and accuracy of store-and-forward teledermatology based on patient-provided images and history as a triage tool for outpatient consultation. Patients referred by their general practitioner provided a history and images via the Internet. The information was reviewed by one of 12 teledermatologists and the patient then visited a different dermatologist in person within two days. Three independent dermatologists compared the remote and in-person diagnoses in random order to determine diagnostic agreement. Broader agreement was also measured, by comparing the main disease groups into which the two diagnoses fell. The teledermatologists indicated whether an in-person consultation or further investigations were necessary. There were 105 eligible patients, aged four months to 72 years, who were willing to participate. For the 96 cases included in the analysis, complete diagnostic agreement was found in 41% ( n= 39), partial diagnostic agreement in 10% ( n= 10) and no agreement in 49% ( n= 47). There was disease group agreement in 66% of cases ( n= 63). Nearly a quarter (23%) of participating patients could have safely been managed without an in-person visit to a dermatologist.

Dermatologists and Allergists Have Far More Experience and Use More Complex Treatment Regimens in the Treatment of Atopic Dermatitis Than other Physicians

Background:

Atopic dermatitis (AD) is a prevalent skin condition, especially in the pediatric population. Whereas it has been shown that dermatologists prefer using more intensive therapy for AD than generalists, actual drug utilization has not been quantified.

Objective:

The purpose of this study is to characterize visits for and treatment of AD in the office-based setting.

Methods:

National Ambulatory Medical Care Survey data from 1990 to 1997 was analyzed to determine the use of topical corticosteroids (including their relative potencies), oral antibiotics, and oral antihistamines in the treatment of AD.

Results:

There were an estimated 900,000 outpatient visits per year for AD. If in some visits to generalists the diagnosis for AD was miscoded as contact dermatitis, there may have been as many as 3 million outpatient visits per year for AD. Topical corticosteroids were used in 67% of visits with a mean potency rank of 4.5 (4.3, 4.8 95% CI). Dermatologists saw 48% of all visits for AD (63 yearly visits/physician) and allergists saw 10% of visits (30 yearly visits/physician). Other physicians saw from 0.1 to 2 yearly visits per physician. Dermatologists were the most likely to use topical corticosteroids (81% of visits) and high-potency corticosteroid agents (22% of visits). Dermatologists and allergists were the only physicians to prescribe ultrahigh-potent corticosteroid agents (12% and 9% of visits, respectively) and were more likely than other physicians to use multiple-agent regimens (21% and 27% of visits treated with a corticosteroid agent, respectively).

Conclusions:

Dermatologists and allergists have more expertise in the management of AD than other physicians, as suggested by their higher per capita visits and greater use of complex topical corticosteroid regimens.

Physiological referrals for paediatric musculoskeletal complaints: A costly problem that needs to be addressed

BACKGROUND/OBJECTIVE

Referrals to paediatric orthopedists for physiologically normal conditions consume limited resources and delay care for patients. The goal of the present study was to formally define such referrals and determine their prevalence.

METHODS

A retrospective review evaluated consecutive referrals to a single tertiary paediatric orthopedic centre over two eight-month periods. Referrals from family physicians and paediatricians were retained for analysis. Physiological referrals were defined as a final orthopedic diagnosis of 'within physiological norms'; and no scheduled follow up.

RESULTS

Physiological conditions represented 22.5% of referrals. The type of referring physician did not determine referral quality. Flat foot, intoeing and genu varum/valgum exhibited physiological referral rates that exceeded 40%.

CONCLUSION

Physiological referrals constitute a large portion of the outpatient paediatric orthopedic practice and represent a substantial unnecessary cost to the Canadian medical system. Future strategies to improve referral quality should target undergraduate and postgraduate musculoskeletal education.

Prevalence of metabolic syndrome in patients with psoriasis: a population-based study in the United Kingdom

Increasing epidemiological evidence suggests independent associations between psoriasis and cardiovascular and metabolic disease. Our objective was to test the hypothesis that directly-assessed psoriasis severity relates to the prevalence of metabolic syndrome and its components.

Population-based, cross-sectional study using computerized medical records from The Health Improvement Network Study population included individuals aged 45-65 years with psoriasis and practice-matched controls. Psoriasis diagnosis and extent were determined using provider-based questionnaires. Metabolic syndrome was defined using National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III criteria.

44,715 individuals were included: 4,065 with psoriasis and 40,650 controls. 2,044 participants had mild psoriasis (≤2% body surface area (BSA)), 1,377 had moderate (3-10% BSA), and 475 had severe psoriasis (>10% BSA). Psoriasis was associated with metabolic syndrome, adjusted odds ratio (OR) 1.41 (95% CI 1.31-1.51), varying in a “dose-response” manner, from mild (adj. OR 1.22, 95% CI 1.11-1.35) to severe psoriasis (adj. OR 1.98, 95% CI 1.62-2.43).

Psoriasis is associated with metabolic syndrome and the association increases with increasing disease severity. Furthermore, associations with obesity, hypertriglyceridemia and hyperglycemia increase with increasing disease severity independent of other metabolic syndrome components. These findings suggest that screening for metabolic disease should be considered for psoriasis, especially when extensive.

Validity of The Health Improvement Network (THIN) for the study of psoriasis

BACKGROUND

Psoriasis is a common disease frequently studied in large databases. To date the validity of psoriasis information has not been established in The Health Improvement Network (THIN).

OBJECTIVES

To investigate the validity of THIN for identifying patients with psoriasis and to determine if the database can be used to determine the natural history of the disease.

METHODS

First, we conducted a cross-sectional study to determine if psoriasis prevalence in THIN is similar to expected. Second, we created a cohort of 4900 patients, aged 45-64 years, with a psoriasis diagnostic Read Code and surveyed their general practitioners (GPs) to confirm the diagnosis clinically. Third, we created models to determine if psoriasis descriptors (extent, severity, duration and dermatologist confirmation) could be accurately captured from database records.

RESULTS

Psoriasis prevalence was 1·9%, and showed the characteristic age distribution expected. GP questionnaires were received for 4634 of 4900 cohort patients (95% response rate), and psoriasis diagnoses were confirmed in 90% of patients. Duration of disease in the database showed substantial agreement with physician query (κ = 0·69). GPs confirmed that the psoriasis diagnosis was corroborated by a dermatologist in 91% of patients whose database records contained a dermatology referral code associated with a psoriasis code. We achieved good discrimination between patients with and without extensive disease based on the number of psoriasis codes received per year (area under curve = 0·8).

CONCLUSIONS

THIN is a valid data resource for studying psoriasis and can be used to identify characteristics of the disease such as duration and confirmation by a dermatologist.

[Effectiveness of primary care physicians and dermatologists in the diagnosis of skin cancer: a comparative study in the same geographic area]

BACKGROUND

skin cancer is the most common malignant tumor in white individuals. Early diagnosis and treatment are key factors in reducing morbidity. We performed a prospective observational study throughout 2008 to assess the ability of primary care physicians to diagnose nonmelanoma skin cancer.

METHODS

the study was undertaken in a single geographic area corresponding to the region served by a primary health care center. Patients who were referred to a dermatologist were included if the primary care physician indicated skin cancer in the differential diagnosis on the referral form. Patients were also included if the dermatologist suspected skin cancer even if the referral from primary care had not indicated it.

RESULTS

primary care physicians had a sensitivity of 0.45 and a specificity of 0.16 for the diagnosis of skin cancer, whereas dermatologists had a sensitivity of 0.97 and a specificity of 0.75. The α statistic as a measure of agreement was -0.56.

CONCLUSIONS

The ability of primary care physicians to diagnose skin cancer was appreciably lower than that of dermatologists. This may result in substantial delays in the provision of appropriate care for patients with skin cancer considering the role played by primary care physicians in screening for the disease in the Spanish national health system.

Incidence of psoriasis in children: a population-based study

BACKGROUND

Although psoriasis is considered to have a dual peak in age of onset, currently no studies exist regarding the incidence of psoriasis in children.

OBJECTIVE

The objective of this study was to determine the incidence of psoriasis in childhood.

METHODS

A population-based incidence cohort of patients aged younger than 18 years first given the diagnosis of psoriasis between January 1, 1970, and December 31, 1999, was assembled. The complete medical record of each child was reviewed and psoriasis diagnosis was validated by a confirmatory diagnosis in the medical record by a dermatologist or medical record review by a dermatologist. Age- and sex-specific incidence rates were calculated and were age and sex adjusted to 2000 US white population.

RESULTS

The overall age- and sex-adjusted annual incidence of pediatric psoriasis was 40.8 per 100,000 (95% confidence interval: 36.6-45.1). When psoriasis diagnosis was restricted to dermatologist-confirmed subjects in the medical record, the incidence was 33.2 per 100,000 (95% confidence interval: 29.3-37.0). Incidence of psoriasis in children increased significantly over time from 29.6 per 100,000 in 1970 through 1974 to 62.7 per 100,000 in 1995 through 1999 (P < .001). Chronic plaque psoriasis was the most common type (73.7%), and the most commonly involved sites were the extremities (59.9%) and the scalp (46.8%).

LIMITATIONS

The population studied was a mostly white population in the upper Midwest.

CONCLUSION

The incidence of pediatric psoriasis increases with increasing age. There is no apparent dual peak in incidence. The incidence of pediatric psoriasis increased in recent years in both boys and girls.

[Diagnostic agreement between primary and hospital care in the assessment of basal cell carcinoma]

OBJECTIVE

To evaluate the diagnostic agreement between primary and hospital care.

METHODS

Cross-sectional study. 491 patients who sought primary care for symptoms of suspected basal cell carcinoma and were referred to a dermatologist. The Kappa index was used to evaluate diagnostic concordance between primary and hospital care.

RESULTS

The more frequent site of diagnosis was face (73.9%). The most frequent differential diagnosis in primary care was nevi (5.9%) while that in specialist care was actinic keratoses (2.2%). The diagnostic agreement was very low (kappa = 0.071; 95% IC = 0.0-0.15).

CONCLUSIONS

The degree of agreement between primary and specialist care was low.

Suspected skin malignancy: a comparison of diagnoses of family practitioners and dermatologists in 493 patients

BACKGROUND

In the Irish health system, dermatology patients present to their family practitioner for diagnosis and treatment, and are referred to a dermatologist for a second opinion where diagnosis is in doubt or when there has been therapeutic failure. The level of expertise in dermatology amongst family practitioners varies considerably.

AIM

To compare the diagnoses of general practitioners and dermatologists over a selected period in patients with a possible diagnosis of skin cancer.

METHODS

Four hundred and ninety-three patients were seen by one of two dermatologists over a 1-year period at a rapid referral clinic for patients suspected by their family practitioners of having unstable or possibly malignant skin lesions; 213 of these patients had a diagnosis made on clinical examination by the dermatologist, while 264 had diagnostic or therapeutic biopsies performed; 16 patients defaulted on surgery.

RESULTS

The diagnoses of the family practitioners agreed with the diagnoses of the dermatologists on patients diagnosed clinically in 54% of cases. Thirty-eight patients had histologically proven skin malignancy. These were diagnosed accurately by the referring family practitioner in 22% of patients, while the dermatologists made the correct diagnosis prior to biopsy in 87%.

CONCLUSIONS

In over 50% of cases diagnosed clinically, the dermatologist and family practitioner agreed. Histologically proven skin cancers were diagnosed accurately in only 22% of cases by family practitioners, compared to 87% of cases by dermatologists. Specific areas of diagnostic difficulty for family practitioners include benign pigmented actinic and seborrheic keratoses, squamous cell carcinoma, and melanoma. Postgraduate education for family practitioners should be directed towards these areas of deficiency. Dermatologists had difficulty distinguishing pigmented actinic keratoses from melanoma.

[Validity of the clinical diagnosis of the basal cell carcinoma in primary health care]

OBJECTIVE

To measure the validity of the clinical diagnosis of the basal cell carcinoma (BCC) in primary care.

DESIGN

Cross-sectional study.

SETTING

Primary health care Area 8 in Madrid. PATIENTS AND ITNERVENTIONS: A study was carried out on a group of patients that had been histopathologically diagnosed of BCC and on another that had received any of the most frequent differential diagnoses. A sample estimate was made with the most unfavourable situation of a sensitivity and a specificity of 50%, a precision of 5%, a confidence of 95% and losses of 20%. It was estimated that 962 cases were necessary.

MEASUREMENTS

The histopathological diagnosis (gold standard) were compared to the clinical diagnosis. Sensitivity, specificity, predictive values, likelihood ratios and global value were estimated.

RESULTS

963 patients were included of which 7.6% were lost 890 cases were studied, 491 with BCC and 399 with differential diagnoses. The most frequent location of BCC was the face (65.8%). Sensitivity was 27.5% (95% CI, 23.531.5%), specificity 90.5% (95% CI, 87.5-93.5%), the global value of 55.7% (95% CI, 52.7-58.7%), positive predictive value, 78.0% (95% CI, 72.084.0%) and negative predictive value 50,3% (95% CI, 46.354.3%).

CONCLUSIONS

Validity was moderate with low sensitivity and very low positive predictive value, the latter estimated for its expected prevalence. The clinical diagnosis of BCC in primary health care must be complemented with other diagnostic tests.

Allergists and dermatologists have far more expertise in caring for patients with urticaria than other specialists

BACKGROUND

Urticaria is a common disease for which numerous treatments have been described, yet there is little information about what agents are commonly used to treat urticaria. There may be differences in the way in which urticaria is treated by different medical specialties.

OBJECTIVE

The purpose of this study was to characterize the visits and treatments of urticaria in office-based practices.

METHODS

National Ambulatory Medical Care Survey data from 1990 to 1997 were analyzed to determine patient populations, medications used, and physician specialties for visits of urticaria.

RESULTS

Women accounted for 69% of all patient visits, but an equal gender distribution was observed in patients 18 years of age and younger. There was a bimodal age distribution with peak visits in patients aged birth to 9 years and 30 to 40 years. H(1) antihistamines and systemic corticosteroids were used in 56% and 14% of visits, respectively. Other medications reported as useful in the treatment of urticaria were used in 12% of visits. Allergists and dermatologists had a mean of 47 and 37 visits per physician per year, respectively, compared with all other physicians who averaged fewer than 10 visits per physician per year. Allergists were the least likely to use a corticosteroid agent (6% of visits), whereas internists were the most likely (29% of visits). Dermatology and allergy recorded a relatively large percentage of visits for urticaria that were referred for their condition by other physicians (49% and 25% of visits, respectively).

CONCLUSION

We observed a bimodal utilization curve for age and urticaria not previously described. H(1) antihistamines remain the mainstay in treatment of urticaria, whereas the low use of systemic corticosteroids likely reflects physicians' understanding of their secondary function in the treatment of urticaria.

Australian teledermatology: the patient, the doctor and their government

Telemedicine is an emerging technology within Australia. We review the historical development of telemedicine and discuss the clinical and non-clinical issues surrounding its practice in this country. Teledermatology is one application of telemedicine. We discuss the potential impact of teledermatology on patients, doctors and third parties such as government. So far, teledermatology has received little attention from Australian dermatologists. By contrast, the Government and other organizations are showing keen interest in establishing infrastructure within this country. We believe it is time for dermatologists to become more involved in the practice and politics of telemedicine within Australia.

Nondermatologists are more likely than dermatologists to prescribe antifungal/corticosteroid products: an analysis of office visits for cutaneous fungal infections, 1990-1994

BACKGROUND

Dermatologists have greater accuracy than nondermatologists for diagnosis of skin disease. However, it is not clear whether this affects medical outcome.

OBJECTIVE

We tested the hypothesis that nondermatologists would be more likely than dermatologists to prescribe combination products for the treatment of common fungal skin infections.

METHODS

We analyzed office-based physician visits for fungal skin infections recorded in the 1990-1994 National Ambulatory Medical Care Survey.

RESULTS

There were 4.1 million visits for cutaneous fungal disease of which 82% were to nondermatologists. Nondermatologists were more likely to prescribe combination agents (34.1%) than dermatologists (4.8%, p=0.001). If the percentage of combination agents used by nondermatologists was reduced to that of dermatologists, an estimated $24.9 million or $10.3 million would be saved if clotrimazole or ketoconazole, respectively, were the substituted drug for the combination agent clotrimazole/betamethasone dipropionate.

CONCLUSION

Nondermatologists are more likely to use a more expensive, less effective regimen than are dermatologists, suggesting that dermatologists are more cost-effective than nondermatologists in the treatment of common fungal skin disorders.