Data Analytics in Healthcare: A Tertiary Study

The field of healthcare has seen a rapid increase in the applications of data analytics during the last decades. By utilizing different data analytic solutions, healthcare areas such as medical image analysis, disease recognition, outbreak monitoring, and clinical decision support have been automated to various degrees. Consequently, the intersection of healthcare and data analytics has received scientific attention to the point of numerous secondary studies. We analyze studies on healthcare data analytics, and provide a wide overview of the subject. This is a tertiary study, i.e., a systematic review of systematic reviews. We identified 45 systematic secondary studies on data analytics applications in different healthcare sectors, including diagnosis and disease profiling, diabetes, Alzheimer's disease, and sepsis. Machine learning and data mining were the most widely used data analytics techniques in healthcare applications, with a rising trend in popularity. Healthcare data analytics studies often utilize four popular databases in their primary study search, typically select 25-100 primary studies, and the use of research guidelines such as PRISMA is growing. The results may help both data analytics and healthcare researchers towards relevant and timely literature reviews and systematic mappings, and consequently, towards respective empirical studies. In addition, the meta-analysis presents a high-level perspective on prominent data analytics applications in healthcare, indicating the most popular topics in the intersection of data analytics and healthcare, and provides a big picture on a topic that has seen dozens of secondary studies in the last 2 decades.

Predictors of abnormal cardiovascular autonomic function measured by frequence domain analysis of heart rate variability and conventional tests in patients with type 1 diabetes

OBJECTIVE

Frequency domain analysis of heart rate variability (HRV) is used to assess cardiovascular autonomic function. There are no prospective data on the sensitivity of its various components to glycemia or other diabetes-related risk factors compared with conventional tests and with other complications of diabetes.

RESEARCH DESIGN AND METHODS

In 1985, possible risk factors of future complications were determined in 115 children with type 1 diabetes. In 1996, the presence of complications (HRV analysis, conventional tests of autonomic function, urinary albumin excretion rate [UAER], and retinopathy) were assessed in 83 of these patients (age 32 +/- 1 years, duration of diabetes 22 +/- 1 years).

RESULTS

Poor glycemic control (measured as lifetime glycemic exposure or HbA1c in 1985) was the most important independent predictor of decreases in all measures of absolute power of HRV (total power [TP] and very low frequency, low frequency [LF], and high frequency [HF] power) and square root of the mean square of R-R interval differences but not of changes of normalized measures or ratios (normalized HF and LF LF/HF). Other significant independent predictors of autonomic dysfunction were late age of onset of diabetes, female sex, and high BMI. To examine the sensitivity of the various tests to glycemia, the patients were divided into tertiles based on lifetime glycemic exposure (A1c months). Glycemic exposure in the tertiles averaged 194 +/- 25 A1c months (20 years of HbA1c 0.8% above normal), 556 +/- 19 A1c months(20 years of HbA1c 2.3% above normal), and 963 +/- 30 A1c months (20 years of HbA1c 4% above normal). Tests of complications that were significantly abnormal in patients already in the lowest tertile and were correlated with glycemia were TP and severity of retinopathy. Of conventional tests, only the ratio of length of R-R intervals during expiration to inspiration (E/I ratio) was significantly related to glycemic exposure, but it required high glycemic exposure (20 years of HbA1c 4% above normal) to be abnormal. UAER was significantly increased only in the highest tertile of glycemic exposure.

CONCLUSIONS

TP and retinopathy score were much more sensitive to antecedent glycemia than conventional tests of autonomic function or UAER and were significantly abnormal in patients exposed to approximately 20 years' duration of an HbA1c 0.8% above normal.

Strabismus in children with cerebral palsy

In 48 children with cerebral palsy the characteristics of the squint and amblyopia were analyzed, also with respect to the features of cerebral palsy and to birth weight. Strabismus of congenital esotropia type was found to be common, as was also exotropia of early onset. Spontaneous alternation or an accommodative component of the squint was present only in a few cases. There was no evidence of an accumulation of any strabismus type in the different subgroups of cerebral palsy, whereas amblyopia or an obvious risk for amblyopia was found in the great majority of the cases. Some kind of amblyopia treatment was given to 34. Most of them showed improvement of the visual capacity which encourages treatment of amblyopia, even in children with cerebral palsy.

Rod-cone dystrophy of the retina. Continuation of a family study described in 1923

In 1923 Alkio described a sibship with 4 children showing macular dystrophy. In the literature this has been classed among the cone dystrophy group. However, Alkio's patients later became completely blind by the age of 50. According to the hospital records one of them showed marked destruction and pigment degeneration throughout the fundus. The daughter of one of those affected has healthy eyes, but two of her three sons are affected in the same way as their grandfather. They were studied by us in 1987. These two males showed the bull's eye type of macular dystrophy with visual acuity of 20/30 resp 20/50, marked dyschromatopsia, central scotoma in the visual field for weak markers, extinguished ERGs and subnormal EOGs. Dark adaptation was considered pathological especially during the cone phase. The peripheral fundus was within normal limits. The parents of the two patients have a common ancestor born in 1720. Autosomal recessive inheritance is therefore very likely. We think that the disorder is closer to the rod-cone dystrophy group than to cone or cone-rod degenerations.

Children referred for pleoptic treatment. A survey on aspects considering referral for examination, role of screening programmes, previous therapy and compliance

The patient histories of 53 unselected children referred for pleoptic treatment were evaluated. The age of the patients ranged from 7 to 12 years, and the mean age was 8.8 years. Information concerning the history was obtained from a questionnaire answered by the parents. The data concerning the ocular conditions were available in the case records. In 83% of the children the diagnosis of functional amblyopia had already been made before school age. During the first 3 years of life altogether 38% were diagnosed outside of routine screening programmes. When the children caught by screening were added, the proportion of those diagnosed before the age of four was 45%. The practice of referring patients from the child health center to the ophthalmological examination was unsatisfactory in some children (19%). Poor compliance was noted still more often (at least in 58%). Occlusion therapy had been used by 92% of the children, and in 42% alternating complete occlusion had been prescribed.

Optic neuritis in children and its relationship to multiple sclerosis: a clinical study of 21 children

The optic neuritis of 21 children aged between four and 14 years generally was characterized by bilateral involvement (62 per cent) and papillitis (76 per cent). Often acute infections or vaccinations were preceding events. Frequently there was pleocytosis during the disease process, with production of IgG, oligoclonal and viral antibodies, which increased during follow-up. Nine of these children (eight female) later developed multiple sclerosis, with unilateral involvement of the optic nerves and HLA Dr2 positivity. Disseminated effects on the central nervous system were similar to those of adults with multiple sclerosis. In all cases these relapses occurred within one year of the optic neuritis. EEGs did not differentiate those who developed multiple sclerosis from those who did not, but four of five patients with multiple sclerosis who were followed-up for a year or more had paroxysmal discharges, and one of the four had manifest epilepsy. Magnetic resonance imaging, visual and sensory evoked potentials and CSF studies were helpful in diagnosing multiple sclerosis. The visual prognosis was good in most cases. 17 children had no or only slight neurological disability at the end of follow-up; the other four had moderate to severe disability. This study suggests that optic neuritis is a diffuse disease, not merely affecting the optic nerves, and that the immunological events typical of multiple sclerosis can start in childhood.

Optic neuritis during lactation

The condition called "lactation optic neuritis" has been previously considered a clinical entity of its own. Four women, who developed optic neuritis within 1-12 months while breast-feeding their infants, were investigated ophthalmologically and neurologically in order, to find specific clinical features for this condition. The course of the disorder was similar to classic optic neuritis without lactation. The clinical history and laboratory findings in three of the four patients suggested a demyelinating disorder. It is possible that the decreased immunosuppressive activity just after pregnancy induces the manifestation of an underlying demyelinating disease. The existence of "lactation optic neuritis," however, is questioned as a separate entity of its own. Lactation together with decreased immunosuppression may merely act as a provocateur in the onset of optic neuritis, which in many cases is the first clinical manifestation of incipient multiple sclerosis.

Ocular findings in four siblings with pseudoxanthoma elasticum

In a family consisting of 8 surviving siblings, pseudoxanthoma elasticum was diagnosed in 4 sisters. One of them had a severe visual handicap, and another a slight decrease of the visual acuity because of the ocular lesions. The other 2 sisters also had fundal lesions, but they were visually symptom-free. Great variation was also found in the appearance of the ocular lesions in the affected siblings. In addition to the angioid streaks, the fundal findings in the probands affected included changes of the retinal pigment epithelium, exudative maculopathy, optic disc drusen and 'fire-work'-pattern of drusen of the Bruch's membrane. A similar variety of alterations was also found in the histopathology of the skin.

Immunological studies on serpiginous choroiditis

Immunological studies on 15 patients with serpiginous choroiditis gave no definite indications of the aetiology of the choroidal vascular lesion which appears to be the initial failure in this disorder. On the basis of the patients' history, recurrencies, and clinical and fluorescein angiographic features, it was suspected that the disorder was of inflammatory origin, probably vasculitis due to an abnormal immune response. To some extent this was supported by the laboratory findings. Of the histocompatibility antigens, HLA-B7 was found more frequently than expected in a Finnish population (54.5% versus 24.3%; P less than 0.05). Increased levels of antibacterial antibodies, ASO or ASTA, were found in eight patients and antiviral (herpes simplex) antibodies in two. One patient had earlier been treated due to positive syphilis serology, and one had an increased serum level of IgM as well as positive latex reaction in a dilution of 1:16. The serum concentration of complement component C3 was slightly decreased in three of the six patients studied and at the lower limit of the normal range in one. No manifestations suggesting systemic disease were found.

Subretinal and disc neovascularisation in serpiginous choroiditis

Three out of 15 patients with serpiginous choroiditis who have been followed up for 1 to 10 years (mean 4.9 years) developed subretinal neovascularisation in the macula. In one eye new vessels were treated with argon laser without attaining permanent obliteration, in the second eye the neovascular membrane was regarded as untreatable because it was under the fovea, and in the third eye new vessels became obliterated spontaneously after atrophy of the surrounding choriocapillaris and the pigment epithelium of the retina. In a furth patient disc new vessels were seen at the active stage of serpiginous choroiditis; these new vessels disappeared after scarring of the initial chorioretinal lesions.

A follow-up study on serpiginous choroiditis

Fifteen patients suffering from serpiginous choroiditis were followed up for 1 to 10 years (mean 4.9 years). There were 7 women and 8 men with ages ranging from 20 to 65 years (mean 35 years). In 13 patients both eyes were involved. Ten of the 15 patients had both inactive scars and fresh lesions when first seen. The individual lesions resolved in a few weeks but, due to the gradual extension of the primary lesions centripetally in the shape of halos or pseudopods, signs of activity were observed for 1 to 9 months after the initial examination. After an interval of 3 months to 4 years, new recurrences were found in 8 patients; in some of them progression was noticed on serial fundus photographs only. Central vision was lost in 6 eyes, in 2 of them due to a subretinal neovascular membrane. Progression and recurrences could not be prevented by antituberculous medication or systemic corticosteroids. The cause of serpiginous choroiditis remains unknown but, on the basis of the fluorescein angiography, occlusion of the uveal vessels, possibly due to an immune vasculitis, is suggested. Immunological studies revealed no signs of diffuse vasculitis. Of the histocompatibility antigens, HLA-A2 was found in five and HLA-B7 in 4 of the 6 patients studied.

Dominant progressive cone-rod dystrophy

The report describes a Finnish family in which retinal lesions associated with a considerable visual loss have been found in 19 probands in 5 consecutive generations. The progressive cone-rod dystrophy diagnosed in the probands shows an autosomal dominant mode of inheritance. The onset of the disease was noticed in most of the probands early during the first decade of life. In the young diseased probands the fundal lesions showed the pattern found in pure cone dystrophies. Elder probands, however, had lesions and dysfunctions indicating an obvious rod involvement in addition to the cone dystrophic pattern. The fundal lesions included very extensive pigmentation in most of the elder probands with the disease. In addition to the retinal lesions, considerable astigmatism and lens opacities at the level of the posterior capsule were found in a great proportion of the probands.

Characteristics of optic disc in healthy school children

The ophthalmoscopic features of the optic discs were studied in a series of 411 non-selected school children representing four age groups from 7 to 15 years. The distribution of the cup disc diameter ratios (C/D) showed that in the majority of the eyes (58.8%) the ratio was 0.2--0.3, independently of the age group. The highest ratio recorded, 0.7, was found in two eyes of the series. An asymmetry of 0.2 or more in the C/D ratios of the eyes was found in 5.2% of the children studied. The correlation between C/D ratio and the age or refraction was not statistically significant although C/D ratio of 0.4 or more was significantly commoner in myopia of -2.0 D. or more than in the other eyes. A preponderance of large C/D ratio was also found in children with a birth weight of 2500 g or less but the difference from the distribution in the total series was not significant. Cilioretinal arteries were detected in 17.7% of the eyes and in 27.3% of the subjects studied. In 8.1% of the children the condition was bilateral. In children with a birth weight of 2500 g or less cilioretinal arteries were found in more than half of the cases.

[Butterfly-shaped dystrophy of the macula with absent pre-beta-fraction of the electropherogram of the serum lipoproteins (author's transl)]

A case of butterfly-shaped dystrophy of the macula is described. Clinical and electrophysiological data are compared with those of 11 cases described in the literature. An aberrant electropherogram of the lipoproteins examined at two different laboratories was found to be present. The serum lipoproteins showed total lack of the pre-beta-fraction. Two children of the patient were examined, too. They showed minimal macular changes which however did not justify the diagnosis of butterfly-shaped dystrophy. Their pre-beta-lipoprotein fractions of the electropherogram were below the Finish standards. The proband is the first case of butterfly-shaped macular dystrophy described from Finland and therefore it was not possible to control the laboratory findings on other cases. The absence of the pre-beta-lipoprotein fraction might be an important feature of butterfly-shaped dystrophy of the macula.

Measles retinopathy during immunosuppression

A 14-year-old boy had an acute attack of measles while on cytotoxic chemotherapy for a testicular neoplasm. Two months later a fatal measles encephalopathy developed, verified by histological, ultrastructural, and immunofluorescent studies. Ophthalmoscopy showed progression of flat depigmented areas of the retina as well as prominent lesions mimicking central serous retinopathy or retinitis. Histopathological studies showed focal retinal necroses with invasion of pigment-laden macrophages into the retina. There were no inflammatory cell infiltrations in the choroid. The presence of structures with the morphological and antigenic properties of measles virus in the affected areas of the retina was shown by electron microsocpy and indirect immunofluorescence. With the increase of immunosuppressive therapy for various purposes the incidence of opportunistic measles virus infections is likely to rise. In the clinical management of such complications ophthalmological examination may prove very helpful.

Fatal measles encephalopathy with retinopathy during cytotoxic chemotherapy

A 14-year-old boy receiving post-operative cytotoxic chemotherapy for a testicular rhabdomyosarcoma developed a fatal encephalopathy associated with retinal changes 2 months after an episode of acute measles. Post-mortem histological examination showed intranuclear inclusion bodies in the neurons and glial cells, but inflammatory cell infiltrations were absent. Electron-microscopic and immunofluorescent studies revealed intracellular masses of paramyxovirus nucleocapsid-like structures, which had the morphological and antigenic properties of measles virus. Recent reports have emphasized the possibility of occurrence of a similar encephalopathy in treated childhood leukemia. It is evident, however, that this potentially fatal complication must be borne in mind when measles is contracted during any form of cytotoxic treatment or immunosuppression. Retinal changes may be of value for the diagnosis during life. We propose the designation "measles encephalopathy during immunosuppression" (MEI) for this condition.

Echovirus type 7 isolated from conjunctival scrapings

Echovirus type 7 was isolated from 7 conjunctival scrapings obtained during an epidemic of meningoencephalitis caused by the same virus. The patients suffered from conjunctivitis or keratoconjunctivitis, and also had gastrointestinal symptoms, fever, headache and lymphadenopathy early in their illness. Two characteristics of the isolated strains were not in agreement with those of the standard echovirus type 7: they adapted only slowly to cell cultures, and no viral hemagglutinin for human red blood cells could be demonstrated. Our data suggest an etiologic association of echovirus 7 with eye disease.

Neurological and developmental findings in children with optic disc drusen

In ophthalmoscopy, optic disc drusen often bear a fallacious resemblance to true papilloedema and some of those affected have neurological disorders. Adequate realization among neuropaediatricians of the relation between drusen and these disorders may save some children from neuroradiological and neurosurgical investigations, often considered unavoidable for exclusion of an intracranial process. Systematic evaluation in a series of 50 children with optic disc drusen showed that neurological disorders are common even in subjects brought to examination for other reasons than neurological symptoms. The findings showed accumulation into two subgroups. There was a group of 15 clumsy children with learning difficulties and delayed development of speech. Another group consisted of 20 children with sudden convulsions and/or headache and vomiting, and with EEG abnormalities but otherwise normal neurological findings. In addition, there were a subgroup with miscellaneous abnormalities and a minor group of children in whom no abnormalities were found except for the eye anomaly.

The central vascular pattern of the eyeground in children with drusen of the optic disk

In a series of 50 children with optic disk drusen the anomaly was found to be associated with unusual properties. A cilioretinal artery was more frequent in the series with drusen than in a control series of the same age. The emergence and course of the central retinal vessels were studied in the right-sided fundi of 46 of the children and in two control series (the fundi of the "better" eyes of 46 strabismic children and the fundi of one of the eyes of 10 children or young adults with papilledema). Analysis of the measurements indicated that early branching of the central vessels and vascular tortuosity are so frequently associated with optic disk drusen that they can be considered features of the anomaly. On the other hand, the fundal vascular features in papilledema seem to be distinguishable by the method used from those associated with optic disk drusen. When the peripapillary choroidal vascular pattern was studied by fluorescein angiography, choriocapillaris filling was delayed in about the half of the angiograms. The aberrant vascular features found on and around optic disks with drusen can be explained by an embryonic affection of the developing vascular system at the optic nerve head. In this respect the anomaly seems to resemble congenital disorders of mesodermal origin.

Clinical appearance of optic disc drusen in childhood

In a series of 50 individuals with optic disc drusen diagnosed before the age of 15, the anomaly occurred most often in the form of an elevation of the whole or one part of the optic disc without visible superficial drusen. Superficial drusen were seen only in 15 of the 92 eyes with the anomaly. In those 42 subjects in whom the anomaly was bilateral, it was seldom symmetrical. The reduced visual acuity found in a few cases could be attributed to causes other than the drusen. In 10 eyes the anomaly was observed to be associated with visual field defects. The age distributions of the subjects with visual field defects and with superficial drusen show that they were more common among older children. The superficial position of the drusen and the presence of visual field defects do not, however, have a close cause-and-effect relationship. A cilioretinal artery was observed to co-exist with optic disc drusen with a high frequency, i.e. in more than 40 per cent. Other vascular aberrations were also noted in association with the optic disc anomaly. Neurological symptoms were the most common cause for consultation in the 50 children examined. In more than half of the present cases appearance of the optic disc had contributed to the suspicion of an intracranial expansive process. A fallacious similarity between the elevation of the optic disc caused by buried drusen and optic disc edema caused by increased intracranial pressure presents a problem of differential diagnosis, expressly in younger children.

Serpiginous choroiditis

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