Constructing Matched Groups in Dental Observational Health Disparity Studies for Causal Effects.

INTRODUCTION: Electronic health record (EHR) systems provide investigators with rich data from which to examine actual impacts of care delivery in real-world settings. However, confounding is a major concern when comparison groups are not randomized. OBJECTIVES: This article introduced a step-by-step strategy to construct comparable matched groups in a dental study based on the EHR of the Willamette Dental Group. This strategy was employed in preparation for a longitudinal study evaluating the impact of a standardized risk-based caries prevention and management program across patients with public versus private dental insurance in Oregon. METHODS: This study constructed comparable dental patient groups through a process of 1) evaluating the need for and feasibility of matching, 2) considering different matching methods, and 3) evaluating matching quality. The matched groups were then compared for their average ratio in the number of decayed, missing, and filled tooth surfaces (DMFS + dmfs) at baseline. RESULTS: This systematic process resulted in comparably matched groups in baseline covariates but with a clear baseline disparity in caries experience between them. The weighted average ratio in our study showed that, at baseline, publicly insured patients had 1.21-times (95% CI: 1.08 to 1.32) and 1.21-times (95% CI: 1.08 to 1.37) greater number of DMFS + dmfs and number of decayed tooth surfaces (DS + ds) than privately insured patients, respectively. CONCLUSION: Matching is a useful tool to create comparable groups with EHR data to resemble randomized studies, as demonstrated by our study where even with similar demographics, neighborhood and clinic characteristics, publicly insured pediatric patients had greater numbers of DMFS + dmfs and DS + ds than privately insured pediatric patients. KNOWLEDGE TRANSFER STATEMENT: This article provides a systematic, step-by-step strategy for investigators to follow when matching groups in a study-in this case, a study based on electronic health record data. The results from this study will provide patients, clinicians, and policy makers with information to better understand the disparities in oral health between comparable publicly and privately insured pediatric patients who have similar values in individual, clinic, and community covariates. Such understanding will help clinicians and policy makers modify oral health care and relevant policies to improve oral health and reduce disparities between publicly and privately insured patients.

First aid therapy for corrosive chemical eye burns: results of a 30-year longitudinal study with two different decontamination concepts.

PURPOSE: There is currently uncertainty about the most efficacious decontamination solution for corrosive chemical eye burns. This 30-year longitudinal study evaluated the relative efficacy of two different decontamination methods. Passive decontamination consists of rinsing with tap water, 0.9% normal saline, isotonic buffered phosphate solution, or Ringer's lactate. Active decontamination adds an amphoteric, polyvalent, and chelating component with Previn® (Diphoterine®) solution (Laboratoire Prevor, Valmondois, France). METHODS: A prospective evaluation of patients treated in two specialized eye clinics for eye burns was begun in 1988. Recorded data included exposure circumstances, type of corrosive, different types of first therapy, and clinical treatment and outcome. Patients were treated from clinic admission and up to 24 h after the corrosive chemical burn with rinsing for 15 min using two different protocols. From 1988 to 2005, sterile 0.9% normal saline or Ringer's lactate was used. Since 2006, sterile, hypertonic, amphoteric Previn® solution was used. Comparative statistical analysis was done with the Fisher contingency tables and Wilcoxon tests. RESULTS: There were a total of 1495 patients with 2194 chemically burned eyes. In 1988-2005, the annual incidence was 66.1/year; in 2006-2017, it was 65.5/year. Similar incidences were noted when initial rinsing was with tap water or isotonic buffered phosphate solutions. There was a significantly more severe outcome of corrosive chemical eye burns with any first aid rinsing solutions other than Previn® solution or tap water was used (p < 0.001). Previn® solution or tap water rinsing in the pre-hospital setting and secondary rinsing with Previn® solution in the hospital decreased lesion severity in comparison with all other rinsing solutions (p < 0.001). CONCLUSION: The frequency of corrosive chemical eye burns was comparatively high despite tightening of occupational health and safety regulations over the past 30 years. The severity of corrosive chemical eye burns has been dramatically decreased since the introduction of Previn® solution for initial and secondary rinsing. A new protocol for immediate Previn® solution use by the Cologne Fire Brigade and secondary Previn® solution rinsing in hospital has reduced the frequency of severe corrosive chemical eye burns to less than 60% as compared to the period of 1988-2005 when other rinsing solutions were utilized.

Autologous transplantation of nasal mucosa after severe chemical and thermal eye burns.

Between February 1992 and March 1994, reconstruction of the fornices in 17 patients with extensive symblephara or lid fusion after most severe eye burns was performed with nasal mucosa from the inferior conchae as graft material. The time between accident and transplantation ranged from 2-64 months. All patients were followed for 6 to 31 months. Reconstruction of the fornices was achieved in 13 patients. Postoperative Schirmer-tests revealed markedly improved results. Impression cytology showed a persistence of goblet-cells and an excess of mucus. We have subsequently performed keratoplasties in 5 of these patients and are planning penetrating keratoplasties in a further 8 cases. In 4 patients, partial symblepharon formation recurred within 2-3 months after transplantation of nasal mucosa. The main advantage of nasal mucosa over buccal or labial mucosa may be the transplantation of intraepithelial goblet cells, leading to an improvement and stabilisation of the tear film.

[Therapy of persistent erosion after severe chemical eye burn with the excimer laser]. / Therapie einer persistierenden Erosio nach schwerer Verätzung mit dem Excimer-Laser.

BACKGROUND: The course after severe eye burns is characterized by many complications which require a longlasting and intensive therapy. The success of treatment is menaced especially by superficial problems like persistent erosiones which occur also after keratoplasty. PATIENT: As a cause of persistent erosions, pathological changes of Bowmans' membrane are discussed. Therefore, it was removed by PTK (phototherapeutic keratectomy) in our patient, in order to allow better adhesion of the epithelium to the deeper, less changed layers. THERAPY AND OUTCOME: The patient suffered from a severe burn accident of his right eye with liquid cement. After proliferations were excised twice, we had to glue on a hard contact lens as an artificial epithelium due to a persistent erosion. Later, the development of a bacterial keratitis required keratoplasty. The epithelium remained intact for eleven months, but then an erosion arose and persisted for nine months. Therefore we performed a PTK and the epithelium closed subsequently within four days. CONCLUSION: The treatment of persistent erosions has been very difficult so far, and often procedures like artificial epithelium or even keratoplasty have been necessary. The astonishing course of our patient indicates, that PTK is a promising and less invasive therapy in these cases.

[Tenon-plasty and early keratoplasty in severe chemical eye burns]. / Tenon-Plastik und Frühkeratoplastik bei schwerstverätzten Augen.

In severe eye burns with destruction of extensive areas of the conjunctiva and epibulbar tissue, Tenon plasty has proved to be successful. Because the epithelium fails to cover the denuded stroma, the corneal surface must be protected by an artificial epithelium. If necrolysis occurs, a tectonic keratoplasty must be performed early. The clinical courses of 12 patients with 14 very severely burned eyes are reported. In addition to Tenon plasty, early penetrating keratoplasies with large diameters 10-16 mm were performed up to 3 months after the accident. The follow-up time was between 6 and 34 months (mean 15.1 months). In five cases the Tenon tissue showed marked inflammation, and the keratoplasties developed large, persistent epithelial defects and had to be covered by conjunctiva. In the other cases it was possible to preserve a healthy epithelial layer by applying soft contact lenses. In 79% of the cases an endothelial graft rejection was observed. In about 50% the transplants were lost. Early keratoplasties are mainly for tectonic repair in severely burned eyes. Optical rehabilitation was achieved in only a few cases.

[Long-term results of Tenon-plasty in treatment of severe chemical eye burns]. / Langzeitergebnisse mit Tenon-Plastik behandelter schwerstverätzter Augen.

From November 1986 to December 1993, 50 patients with 62 very severe eye burns were treated with Tenon plasty. Forty-one eyes showed widespread scleral ischemia, while 21 eyes had developed corneoscleral ulcerations. Surgery was done 3-126 days after the injury. A total of 210 quadrants was treated with Tenon plasty. Epithelization of the Tenon sheets was complete within 21 days in 79% and in all eyes up to 51 days. In all eyes corneoscleral ulcerations could be prevented or healed. In 48% isolated symblepharon formation or severe scarring of the fornices developed within 3 months after Tenon plasty. In these cases restoration of the conjunctiva was achieved by transplantation of autologous conjunctiva or nasal and buccal mucosa. Spontaneous epithelization of the burned cornea was achieved in 25.8%. In 36 eyes penetrating keratoplasty was performed. Sixteen (44.5%) grafts failed due to surface problems, while 12 (33.3%) grafts failed because of an endothelial immune reaction. Tenon plasty proved to be successful in preventing early necrolysis of the anterior eye segment in very severe eye burns. However, the prognosis for penetrating keratoplasty in these eyes is limited due to surface problems and immune reactions.

Poor prognosis of severe chemical and thermal eye burns: the need for adequate emergency care and primary prevention.

The epidemiology and wound healing following medical and surgical treatment of 101 patients with 131 severely burnt eyes due to chemical or thermal agents have been analyzed. Most of the accidents occurred at work (72.3%); the majority of the burns were chemical (84.2%), of which 79.8% were caused by alkalis. The long average duration of treatment on ward (5.2 +/- 4.1 months) and the high number of surgical interventions (8.0 +/- 8.0) indicate the difficulties in treatment and the delayed recovery of the affected eyes. Despite improved possibilities of immuno-suppression after keratoplasty (cyclosporin A) and new methods of surgery (Tenon plasty), the possibilities of an optical rehabilitation are still limited. A visual acuity of 6/60 or better was achieved in 39 eyes (32.2%). Immediate irrigation was reported in 56.1% of accidents at the place of work and in 42.8% of accidents sustained at home. There was a significant difference with respect to the extent of damage, the treatment on ward and the number of surgical interventions. The visual prognosis for eyes which received immediate irrigation was significantly improved. Eye protection was not used in any of the 101 cases. Spread of information is necessary for adequate emergency care for eye burns as well as for permanent employment of protective glasses in high-risk occupations.

[Intraocular complications after severe chemical burns--incidence and surgical treatment]. / Intraokulare Komplikationen nach schweren Verätzungen--Häufigkeit und chirurgische Behandlung.

BACKGROUND: The prognosis of severe eye burns is determined by the area of the injured conjunctiva and the damage of the cornea. Furthermore the extension of damage to intraocular structures influences the clinical course and the surgical management. PATIENTS: The clinical course of 66 patients with 90 severely burnt eyes in the time from January 1985 to December 1993 were examined with special regard to primary and secondary intraocular complications. RESULTS: In 62 (68.9%) eyes, the whole anterior eye segment was burnt, while in 28 (31.1%) eyes the damage was limited to the cornea and limbus. A cataract occurred in 23 (25.6%) eyes short time after the burn and an early secondary glaucoma in 14 (15.6%) eyes. In the further clinical course, 41 (45.6%) eyes developed a secondary cataract and 20 (22.2%) eyes a late secondary glaucoma. Within 3 months after the burn, 18 eyes were treated with a Tenon plasty, a penetrating keratoplasty and a cataract extraction. In 12 eyes a cataract extraction was combined with a penetrating keratoplasty more than one year after the injury. In the other cases cataract extraction and keratoplasty were performed in separate operations. In 8 eyes intraocular lenses were implanted. In 15 (16.6%) eyes secondary glaucoma had to be treated by trabeculectomy or by the implantation of a von Denffer implant. Penetrating keratoplasty was performed in 55 eyes, 35 of them were unsuccessful as a consequence of graft rejection or increasing vascularisation. One third of the patients achieved a long-term visual acuity of 0.1 and more. CONCLUSION: After severe burn a high rate of intraocular complications has to be expected. The surgical management of such eyes differs from standard procedures. Principally, all devitalized tissue of the anterior chamber like fibrinous and retrocorneal membranes should be excised in an early stage after the burn. Penetrating keratoplasties and extraction of the cataractous lens should be performed in a combined procedure. The implantation of an intraocular lens is limited to a few special cases.

[Retrospective study of severe alkali burns of the eyes]. / Retrospektive Betrachtung von schweren Alkaliverätzungen der Augen.

BACKGROUND: Alkali burns are of special interest because of the rapid and deep penetration of alkali into the ocular tissues. PATIENTS AND METHODS: This report examines the epidemiology, management and outcome of 42 cases of alkali burns of the eye admitted to the eye clinic of the RWTH Aachen from 1985 to 1992. Aspects examined were the nature of accident, type of alkali, treatment and complications. The intention was to use this information for improvement of prevention and treatment of these cases. RESULTS: The age analysis showed the greatest at-risk population were the 20-40 year-old patients. 73.8% were industrial accidents, 30% happened to builders and labourers, 20% in the chemical industry and 20% in machine factories. At home most of the injuries were caused by lime and drain cleaners. Sodium and potassium hydroxide produced more extended and deeper damages than lime due to their rapid penetration through the ocular tissues. A delayed surgical intervention led to a longer time of stay in hospital and to a higher number of operations. All eyes could be prevented from melting, but an optical rehabilitation (visual acuity > 0.3) was achieved only in a few cases (14.5%). CONCLUSION: There is a need to ensure adequate public awareness of the danger of alkali burns to the eye. Beside the primary prevention, adequate first aid with immediate and continuous irrigation is of paramount importance. A uniform concept for the management of these severe cases is necessary including an antiinflammatory medical and surgical treatment.

[Chemical and thermal eye burns in the residential area of RWTH Aachen. Analysis of accidents in 1 year using a new automated documentation of findings]. / Verätzungen und Verbrennungen im Einzugsbereich der RWTH Aachen. Analyse der Unfälle über 1 Jahr mit Hilfe einer neuen automatischen Befunddokumentation.

BACKGROUND: Until now there were no statistical data on the incidence and the prevalence of eye burns. Therefore we studied all patients coming to our hospital from the area of Aachen with eye burns during the time from September 1990 until August 1991. PATIENTS AND METHODS: All patients underwent a standardized examination including special history of the burning agent, industrial medical aspects and the employers liability insurance association. The documentation of the anterior eye segment pathology was scored separately for each eye encoded by location and special items. This documentation was worked up by the aid of a database (Filemaker II). 171 patients with eye burns were documented during one year. 65 patients had both eyes burned resulting in 236 documented records. RESULTS: The 171 accidents can be divided in 104 (61%) industrial accidents and 64 (37%) housework accidents. 3 accidents were of unknown origin. Classification of burns was scored according to Reim 1991. 208 (88%) eyes showed score I burns, 27 (11.5%) score II and only one patient showed a score III eye burn. We saw 121 (70%) male patients, 39 (23%) female patients and 11 children (7%). The main age group ranged from 16-45 years. 28% (n = 30) of all accidents happened in machine factories, which have thereby in our study the highest incidence of industrial accidents. CONCLUSION: By means of a one-year statistic we found that over 60% of all eye burns were industrial accidents, 28 in machine factories and 20% in service industries. 37% houseworks accidents are very difficult to prevent because of a deficit of safety rules.

[Clinical experiences with adhesive hard contact lenses]. / Klinische Erfahrungen mit aufgeklebten harten Kontaktlinsen.

BACKGROUND: Persistent epithelial defects of the cornea are difficult to treat and can lead to severe complications such as melting processes. Therefore the application of a glued-on hard contact lens as an artificial epithelium has been recommended for many years, to protect the denuded corneal stroma. MATERIALS AND METHODS: This paper presents a 7-year retrospective study on the application of a hard contact lens as an artificial epithelium. 46 patients with 50 eyes were treated with this method from january 1985 to march 1992. The majority of the patients suffered from most severe burns of the whole anterior eye segment (group I: n = 29 eyes) or of the cornea alone (group II: n = 13 eyes). A smaller number of patients (group III: n = 8 eyes) presented corneal melting processes associated with other diseases. RESULTS: The patients of group II and III showed the best outcome concerning spontaneous epithelialization and prognosis for a penetrating keratoplasty. The treatment with a glued-on hard contact lens was limited by the high rate of complications (92%) in group I and II. In one third of the cases of group I these complications led to further surgical interventions (e.g. conjunctivoplasty of the globe). The results also show, that the application of a glued-on hard contact lens in patients with most severe eye burns is a long-term treatment (> one year). CONCLUSION: The poor prognosis of corneas with severe healing problems of the epithelium can be improved by the application of a glued-on hard contact lens as an artificial epithelium. In severe burns of the whole anterior eye segment however, the treatment with an early keratoplasty should be considered.

[Prevalence of tuberculosis in Stuttgart--results of routine tuberculin tests]. / Zur tuberkulösen Durchseuchung in Stuttgart--Ergebnisse von Routine-Tuberkulintests.

From 1986 to 1991 a total of 12,835 tuberculin tests were carried through by the Public Health Office in Stuttgart. In this period the rate of positive reactions increased remarkably, with higher rates as usual, higher for Germans than for foreigners. Possible consequences are discussed.