Evaluación de la efectividad clínica y social de una unidad de dolor crónico

Resum

We present an observational, longitudinal and retrospective study to evaluate the clinical and social effectiveness of a Chronic Pain Unit. Despite the development of pain units in recent decades and the high cost of multidisciplinary treatment programs, pain units are not always effective. In order to know their effectiveness and efficiency, there should be long-term follow-ups. The existing studies are heterogeneous with variable quality, and offer limited evidence of their benefit in the medium or long term. To provide new data that clarify the scope of effectiveness in the treatment of chronic pain, the results obtained in a Chronic Pain Unit with a reference population of 290.000 inhabitants in the Balearic Islands Community treated during an 8-year period will be analyzed. Goals The purpose of the study is to verify and quantify the clinical effectiveness of a chronic pain unit as well as to establish optimal treatments for different types of pain. We will describe the demographic and clinical characteristics of patients at the first visit, and it will be compared with the clinical situation at their last visit to the pain unit. The response of the different types of chronic pain to the established treatments will be analyzed, thus establishing the relationship between the degree of pain remission and the different types of therapies. All of the above could clarify which areas of improvement of the pain unit lead to changes in clinical practice, from protocolizing the most effective treatments in each type of pain to improving the database for future studies. Methods and materials After obtaining informed consent from the patients visited at the Pain Clinic and approval by the ethics committee of our institution, a comparative analysis of analgesic effectiveness (pre and post-treatment) was undertaken. Those patients visited in the Chronic Pain Unit from January 1st, 2.006 to December 31st, 2.013, and whose computerized pain medical histories were complete in all study variables and in all reports studied, were included in the study. The data collection of both the first visit and the last visit was carried out using the forms "Pain Unit Report" and "Successive Pain Unit Report". The first analyzed data were the demographic and socio-labor data, and the duration of the pain. The ratio follow-up visits/first visit was recorded in the whole population as well as in each group. The variables compared were: VAS (Visual Analogue Scale) Intensity, VAS alleviation, VAS Mood, VAS Sleep, Verbal descriptors (no pain, slight, moderate, severe, unbearable), the employment situation, the main diagnosis and the treatment obtained from our medical pain record. The patients were divided into 6 groups: Headache, Low-Back Pain, Musculoeskeletal pain, Neuropathic (including sympathetic), Cancer, and Visceral pains. They were classified into three groups according to the treatment undertaken: "Only pharmacological", "Invasive", or "Other" (acupuncture, transcutaneous electrical nerve stimulation - TENS, and psychological strategies). The descriptive analysis of the distribution of the different types of pain according to age and sex groups was carried out, as well as the number of successive visits in relation to the first visits. The analysis of quantitative (VAS for pain, relief, mood, and quality of sleep) and qualitative (verbal descriptor) variables in the total population and in each of the diagnostic groups both in the first and in the last visit was performed. The discrete quantitative variables were grouped as ordinal qualitative variables defined as mild pain (VAS from 0 to 3), moderate pain (VAS from 4 to 6), and intense pain (VAS from 7 to 10). To establish the degree of remission of pain, the transition from severe pain to moderate pain ("partial remission"), or to mild pain ("complete remission"), or non-modification ("no remission") was analyzed. The bivariate analysis of the changes in the values of VAS and verbal descriptors was carried out according to the types of treatments established, to analyze both the overall effectiveness of the three types of therapy, and the effectiveness in the most prevalent diagnostic groups. Pre-post differences in each group and in total population were assessed using Wilcoxon-signed-Rank test for non-parametric data, while Pain relief rates in each group (%) were assessed using X2 – test. The tools used were a database in Excel 2013 format created with the information obtained from the computerized medical record, and the SPSS16.0 computer program (SPSS Inc®, Chicago, IL, USA) for the calculations and data analysis. Results During the analyzed period, 5,893 patients were visited in the Chronic Pain Unit for the first time. From this initial sample, 2,261 patients were selected according to the inclusion criteria. The mean duration of pain was 5.43 years with a standard deviation of 0.2 years. The mean age was 61 ± 15 years, and pain was more prevalent in women (64%) than in men (36%). In relation to the social and labor situation, 27% of the patients were active population, 25% were retired, and 13% had definitive or transitory incapacity for work. Headache (Group 1) represented 1.99% (n = 45), Low-Back Pain (Group 2) represented 58.55% (n = 1.324), Musculoeskeletal pain (Group 3) represented 26.05% (n = 589), Neuropathic (including sympathetic) pain (Group 4) was 11.18 % (n = 253), Cancer pain (Group 5) was 0.97% (n = 22), and Visceral pains (Group 6) was 1.23% (n = 28). In both sexes, Group 2 was the prevalent one. In the group studied, 23,459 successive visits were made during the period analyzed, which means that for each first visit there were 3.98 successive visits per patient. The patients of Group 1, Group 2, and Group 3 were those with the highest successive / first relationship (5.58, 4.37, and 4.46 respectively), while the patients of Group 5 are those with the lowest successive / first relationship presented (1.92). The treatments used were "Pharmacological only" in 37% of cases, "Invasive" in 38% of cases, and "Other" in 25% of cases. A statistically significant overall improvement (p<0,001) was observed in all the patients in all the variables studied between the first and the last visit analyzed. When assessing each diagnostic group, there were no statistically significant improvements in sleep, relief and mood variables in the Group 1, and in sleep variables in the Group 5. Only a significant improvement in relief variable in the Group 6 was obtained. There were no significant differences between the therapeutic options established in the first visit, although the "Invasive" option was the most common in the category "intense pain", while the option "Only pharmacological" was the most common in the category "mild pain" and “moderate pain ". With all the therapeutic options, the VAS values improved significantly between the first and last visit (p<0,001). When analyzing the degree of remission according to the applied therapy, it was observed that the percentage with "total remission" of the VAS was statistically lower (p<0,001) for the group "Other" in comparison with the other two treatment options. Patients with severe pain were the most prevalent (76%), and when studying their response to treatment, a global "non-remission" rate of 40% was found. This result was justified at the expense of the lack of remission in Group 3 and Group 6. In the comparative analysis of therapeutic efficacy in the most prevalent types of pain, statistically significant differences (p<0,001) were obtained in Group 2 and Group 3. In both groups, a higher rate of "total remission" was obtained with the option "Only pharmacological" or "Invasive" versus "Other" (p<0,001). No differences were observed for any of the options for Group 4. Conclusions By evaluating the results of this study, we can affirm that the systematic self-evaluation of clinical practice in each center should be a priority. It is the way that allows us to know the population to which we give assistance, our effectiveness, and the measures we can take to improve it. The Pain Unit analyzed has had a positive overall clinical impact on the treated population. The patient with severe pain has been predominant, for which the pharmacological and invasive therapies are the most effective. However, intense pain that does not get adequate relief continues to exceed our expectations as pain therapists. It is considered a priority to improve the database, updating the classification of the chronic pain tables according to the "ICD-11", differentiating the different families of drugs, notifying the changes in the social and labor situation during the follow-up, and adding a quality scale of life related to health during the first visit and during the follow-up.