Pain in Chronic Leg- and Foot Ulcers

Design: The study has a non-experimental, explorative and descriptive approach. A cross-sectional questionnaire design, that provides quantitative data, will be used to explore patient's experience of wound-related pain.

Recruitment: Patients will be recruited from outpatient clinics and home-care nursing in Norway. Written informed consent will be obtained from all eligible patients who agree to participate.

The patients will be recruited at the outpatient clinic appointment. Those willing to participate will complete the questionnaire independently and return the questionnaire by mail in a pre-paid envelope. Furthermore, relevant information about the diagnosis/classification of ulcer, comorbidities, the ulcer management and pain management will be collected in a clinical examination, and by talking to the participants. The clinical examination will take place in relation to already scheduled dressing-change, in order to minimize the burden of participating in the study.

Based on clinical experience, and expert opinion, the research group have reason to believe that the ulcers can be classified in three main categories; ulcers with venous insufficiency as main perpetuating factor, ulcers with arterial insufficiency as main perpetuating factor, and ulcers with diabetes as the main perpetuating factor.

This study will not look at the effect-size of an intervention, or test a hypothesis. Therefore, the sample size is calculated based on the need to carry out the planed regression analysis to look at predictors of quality of life for patient with different etiology leg ulcers. In this study, quality of life will be a dependent variable, whereas pain, sleep, age, gender, wound area and possibly social status will be independent variables.

The sample size estimation is based on recommendations from statisticians and literature. The "rule of thumb" recommended indicates a study size of N> 104 + number of independent variables (here 6). This gives N> 110 in each group. The research group have chosen to set the sample size of 120 respondents in each group to take into account any dropouts. Three groups with 120 respondents result in a total sample size of 360 respondents.

The questionnaires Participants will fill out self-report questionnaires. The battery of questionnaires will obtain information about demographic and clinical data, pain characteristics, quality of life and sleep.

Demographic data: Information on age, gender, work situation, education, and living arrangements will be collected. This information will be used to describe the patient sample of the present study.

Clinical data: A research nurse will collect information about the patients' anamnesis and ulcer. Relevant information will be collected on the diagnosis/classification of ulcer, the ulcer management, and pain management. The measures included in this study are standardized measures in the clinic.

Diagnosis and classification of ulcer

The following data will be collected in order for the research-group to classify the different ulcers:

• The patients ulcer diagnosis (as stated by a medical doctor), the presumed causal factor (such as trauma or pressure), comorbidities, localization of the ulcer (on a body map), measure of wound size by multiplying the wounds width (millimeters at the widest) and height (millimeters at the highest).
• Clinical signs of wound-infection (critical colonization): Unusual/bad smell, visible pus, increased moisture, increased or changes in ulcer related pain, redness, swelling, heat, reduced general condition, and fever.
• Circulation of the leg will be assessed by palpation of ankle pulse. If no palpable pulse is found, the pulse will be assessed with Doppler. If unable to detect the pulse with Doppler, the Ankle-brachial pressure index will be calculated.
• Reduced sensibility will be assessed with the monofilament and tuning-fork tests for tactile and vibration sense.
• The presence of visible varices will be registered.
• A photograph of the ulcer and the lower leg and foot will be taken and used to classify the ulcers.
• Bothersome itch is assessed by asking the respondents.

Ulcer management: The research nurse will collect data on the ulcer management, such as the frequency of wound dressing change, if wet or dry dressing/treatment is used, and whether or not the patient has undergone ulcer debridement or revision surgery during the last week. Furthermore, if the patient is recruited at an outpatient clinic, the patient is asked whether this is the first consultation at the clinic.

Pain management: Both medical and non-medical treatment for pain is registered. It will be differentiated whether the pain management is aimed at ulcer pain or other types of pain that the patients may suffer from.

Characteristics of wound-related pain Pain intensity: The 0 - 10 Numeric Rating Scale (NRS) for pain is a one-dimensional measure of pain intensity.

Pain qualities: The Short Form McGill Pain Questionnaire (SF-MPQ) will be used to assess different qualities of the subjective pain experience. The aim of this questionnaire is to capture pain as a multidimensional phenomenon, recognizing the shortcomings of simple pain intensity scales.

The Brief Pain Inventory (BPI): BPI provides information about the location, intensity, treatment and impact of pain.

Temporal pattern of pain: There are no questionnaire available adapted for assessment of pain pattern for use in self-report at one set time. The research group has designed and will test a one-dimensional tool to assess the pattern of wound pain. The first part of the tool is based on the last item of the Pain Quality Assessment Scale where the respondents select one of tree statements reflecting intermittent pain, variable pain and stabile pain. The second part of the tool includes a graph where the respondents indicate subjective level of pain (0 - 10 NRS) every hour during a typical day. Pertaining to level of pain, the participants also mark specific times during the day spent in activity, resting, and sleeping.

Localization of wound-related pain: The respondents will be asked about the location of wound-related pain, and can choose among multiple alternative options, such as directly in the wound or wound-bed, in the wound-edges, in the skin surrounding the wound, in the entire foot, and in the entire leg. The respondents can also write in own words where the wound pain is located.

Quality of life Will be assessed using The EuroQol-5D (EQ-5D) which is a standardized instrument developed by the EuroQol Research Foundation for use as a measure of health outcome applicable to a wide range of health conditions.

Sleep The Insomnia Severity Index (ISI) is a brief self-report instrument measuring the patient's perception of sleep. The ISI targets the subjective symptoms and consequences of insomnia as well as the degree of concerns or distress caused by those difficulties.

Analyses The data will be analyzed with appropriate parametric and nonparametric tests using Statistical Package for the Social Sciences for Windows. The data will be analyzed using means, standard deviations, correlation coefficients, analysis of variance (ANOVA) and regression analyses.

The photographs and clinical ulcer data will be evaluated by the research-group in order to categorize the ulcers, based on predefined criteria for three etiology groups.

Ethical considerations This study is approved by the Regional Committees for Medical and Health Research Ethics in Norway (region south-east). This should assure that the study follows all necessary ethical considerations regarding cross-sectional quantitative research design. Furthermore, the study is reported to the Data Inspectorate. Application for permission to recruit participants has also been sent to the Head of the department in the different clinics and community nursing services where patients will be recruited.

Participation in the study will be voluntary, and there will be no obligation to participate or "penalty" or consequences for not participating. Patients will receive written and oral information about study participation. An introductory letter that describes the purpose and nature of the study and confidentiality of the data, as well as a written consent, form will be handed out to potential participants. Patients willing to participate need to sign the consent form before receiving the questionnaire. Confidentiality will be maintained through coding of participants and removal of identifiers at an early stage in data analysis. Completed questionnaires and codebooks will be stored separately and according to rules and regulations set by the Ethics Committee and the involved hospital and community nursing services. The completed questionnaires will be stored in locked and fire-safe safes. Digital copies of data will be saved on research-servers at the University College of Southeast-Norway (HSN).

The photographs taken of the patients' ulcers will not contain information that can identify the patients. The study nurse will take the photo so that it only visualizes the wound and lower leg/foot. The photo will be allocated the patients study-identification number, and saved electronically on the research server at the HSN. No hard-copies of the photo will be stored.