[German national consensus on wound documentation of leg ulcer : Part 1: Routine care - standard dataset and minimum dataset]

Development of a model to predict closure of chronic wounds in Germany: Claims data analysis

Patients with chronic leg ulcer, pressure ulcer, or diabetic foot ulcer suffer from significant disease burden. With a view to improving healthcare provision sustainably, a predictive model of time to closure (time-to-event analysis) based on claims data was developed. To identify potential predictors of wound closure, clinical information absent from statutory health insurance (SHI) data was modelled. In patients with leg ulcers, age of the patient (hazard ratios [HR] 0.99), increasing number of comorbidities (HR 0.94), inpatient stays (HR 0.74), and treatment by a specialised wound care professional (HR 1.18) were significant predictors of time to closure (adjusted model). In almost all models, the number of inpatient stays and of comorbidities predicted a lower probability of healing. In addition, the age and the sex of the patient were found to be significant predictors in some models (leg ulcer: HR 0.99; pressure ulcer: HR 0.99). Increasing number of comorbidities and inpatient stays were predictors for closure time in all models. Since these predictors may give an indication of wound severity, further clinical information should be considered in future models, as also indicated by the moderate values of the c-statistics. This requires future data linkage between SHI and primary studies (eg, registers).

Expressiveness of an International Semantic Standard for Wound Care: Mapping a Standardized Item Set for Leg Ulcers to the Systematized Nomenclature of Medicine-Clinical Terms

Background

Chronic health conditions are on the rise and are putting high economic pressure on health systems, as they require well-coordinated prevention and treatment. Among chronic conditions, chronic wounds such as cardiovascular leg ulcers have a high prevalence. Their treatment is highly interdisciplinary and regularly spans multiple care settings and organizations; this places particularly high demands on interoperable information exchange that can be achieved using international semantic standards, such as Systematized Nomenclature of Medicine–Clinical Terms (SNOMED CT).

Objective

This study aims to investigate the expressiveness of SNOMED CT in the domain of wound care, and thereby its clinical usefulness and the potential need for extensions.

Methods

A clinically consented and profession-independent wound care item set, the German National Consensus for the Documentation of Leg Wounds (NKDUC), was mapped onto the precoordinated concepts of the international reference terminology SNOMED CT. Before the mapping took place, the NKDUC was transformed into an information model that served to systematically identify relevant items. The mapping process was carried out in accordance with the ISO/TR 12300 formalism. As a result, the reliability, equivalence, and coverage rate were determined for all NKDUC items and sections.

Results

The developed information model revealed 268 items to be mapped. Conducted by 3 health care professionals, the mapping resulted in moderate reliability (κ=0.512). Regarding the two best equivalence categories (symmetrical equivalence of meaning), the coverage rate of SNOMED CT was 67.2% (180/268) overall and 64.3% (108/168) specifically for wounds. The sections general medical condition (55/66, 83%), wound assessment (18/24, 75%), and wound status (37/57, 65%), showed higher coverage rates compared with the sections therapy (45/73, 62%), wound diagnostics (8/14, 57%), and patient demographics (17/34, 50%).

Conclusions

The results yielded acceptable reliability values for the mapping procedure. The overall coverage rate shows that two-thirds of the items could be mapped symmetrically, which is a substantial portion of the source item set. Some wound care sections, such as general medical conditions and wound assessment, were covered better than other sections (wound status, diagnostics, and therapy). These deficiencies can be mitigated either by postcoordination or by the inclusion of new concepts in SNOMED CT. This study contributes to pushing interoperability in the domain of wound care, thereby responding to the high demand for information exchange in this field. Overall, this study adds another puzzle piece to the general knowledge about SNOMED CT in terms of its clinical usefulness and its need for further extensions.

[German national consensus on wound documentation of leg ulcer : Part 2: Routine care - classification of variable characteristics]

BACKGROUND

Standards in the assessment and documentation of disease processes are the basis of guideline-based care. For the treatment of chronic wounds, especially leg ulcers, no approved parameters are available.

OBJECTIVES

Against this background, our aim was to develop standards for the documentation of leg ulcer in routine care. This article presents the recommendations for the classification and characteristics of the variables.

MATERIALS AND METHODS

The development of the documentation standard was based on a systematic literature research and was performed in a Delphi-based consensus process. The national consensus process included meetings as well as web-based questionnaires. The Consensus Group is coordinated by the German Center for Health Services Research in Dermatology (CVderm).

RESULTS

The documentation standards and their variables for leg ulcer routine care were developed in seven meetings of the consensus group. The consensus group consists of 38 delegates of wound care societies, health insurances, wound networks and associations.

DISCUSSION

For each variable, recommended in routine care, a distinct response scheme (defined set of variable characteristics) was defined. As a next step, a structured implementation process is required, which was part of the resolutions of the consensus group.