INTRODUCTION

Breakthrough cancer pain (BTcP) is defined as an acute worsening of pain that appears rapìdly, has a short duration and moderate to high intensity that patients with cancer suffer when they present a stabilized baseline pain, controlled with opioids. BTcP is a frequent problem in cancer patients and is associated with significant morbidity ¹. Data regarding prevalence is inaccurate because a definitive consensus has not been reached as to its definition, but some studies estimate that it may be present between 23% and 93% of cancer patients ². Despite its high prevalence and the major advances made in its treatment, BTcP is still a poorly-known clinical problem, under-researched and frequently treated incorrectly ¹.

In order to alleviate possible lacks in managing BTcP, in 2013 significant representatives of the Sociedad Española de Cuidados Paliativos (Spanish Palliative Care Society - SECPAL), the Sociedad Española del Dolor (Spanish Pain Society - SED), the Sociedad Española de Oncología Médica (Spanish Society of Medical Oncology - SEOM) and the Sociedad Española de Oncología Radioterápica (Spanish Society of Radiotherapeutic Oncology SEOR) published a document of multi-professional recommendations which offered a consensus on the definition of BTcP and gave recommendations to optimize its diagnosis and treatment ¹.

The level of accordance and follow-up with these recommendations in actual clinical practice by the specialist doctors that work in pain units (PU) and in palliative care units (PCU) has not been researched in depth. The objective of this study has been to find out the level of knowledge and of accordance of the professionals involved in managing BTcP with the recommendations of the Scientific Societies (SS). Furthermore, it has evaluated the perception that physicians have of the made of therm in clinical practice. Accordingly, opinions of the professionals were gathered by means of two surveys. By filling out the two questionnaires, each doctor made a self-assessment of clinical habits (self-audit) which evaluated their own patients BTcP, whether the agreed recommendations appear in the guidelines for managing BTcP had been followed.

MATERIAL AND METHODS

An observational analytical study was carried out between April and December 2016. The opinions of professionals were collected at two sequential times, between which there was a personal experience of retrospective self-assessment of prior clinical habits in their clinical practice (self-audit) (Figure 1).

Before starting the field period, the promoter presented the study protocol, together with all working material that the investigators used, to the Ethics Investigation Committee of Santiago-Lugo for evaluation, and its resolution was favorable.

Fig. 1 Esquema del estudio. 

Study instrumentation

The initial questionnaire consisted of an anonymous, confidential way of collecting the personal and subjective perception of professionals related with the level of follow-up (knowledge, acceptance and application) from a list of 12 recommendations of good practices on managing BTcP, selected from the agreed recommendations by the SS ¹ (Table 1). Subsequently, a limited time period was established, where participants were invited to take part in a systematic review of the level of these recommendations' implementation as from data recorded in the CR of their patients. Physicians noted the level of adherence to the recommendations in the CR of cases analyzed. Physicians were offered a reminder (check-list) with a summary of the main recommendations from the expert reference agreement to standardize and optimize rigor in the review of clinical records. Lastly, a final form was distributed to evaluate, as a group, the results of the self-audit anonymously and confidentially. The form recorded opinions on the level of real implementation of the recommendations.

TABLE I SELECTED RECOMMENDATIONS TO EVALUATE BTCP (TAKEN FROM ESCOBAR AND COLS.). 

BTcP: breakthrough cancer pain. IRO: immediate-release opioids. CRO: controlled-release opioids.

The study was carried out in accordance with the ethical requirements of the declaration of Helsinki, Scotland review (October 2000) for medical research involving human subjects. Although the project only gathers professional opinions and trial, it was submitted to approval by an Ethics Committee of Independent Clinical Investigation (Comité Ético de Investigación de Santiago-Lugo) in accordance with the international standards relating to carrying out epidemiological studies laid down in the International Guidelines for Ethical Review of Epidemiological Studies and the recommendations of the Spanish Epidemiology Society (SEE) regarding ethical aspects of epidemiological investigation.

RESULTS

In the study, a total of 202 specialist physicians took part and 905 clinical records of patients with BTcP were reviewed (90.5% of the expected total). A total of 45% of the professionals were women. The median age was 47.9 years old (CI 95%: 46.7-49.05) with a minimum of 33 and a maximum of 67 years old. The professionals worked in the public sector in 83.7%, in the private sector in 2.5% of cases, and 13.9% combined public activity with private. 51,5% of specialists worked in PU (n=104) and 48.5% in CPU (n=98). The distribution of specialties was as follows: 47% anesthetists, 27.7% family doctors, 13.9% of specialists in internal medicine and 11.4% other specialties. Professional experience ranged between 1 and 30 years, with an average of 11.9 years (CI 95%: 10.8-12.9) and a median of 10.5 years. According to the data provided by the professionals themselves, each doctor of the PU attended an average of 8.8 patients with BTcP per week, and each doctor of the CPU attended an average of 15.2 patients with BTcP per week (p <0.01).

A total of 86.6% (n=175) of the professionals were aware of the consensus document "Recommendations for the diagnosis and treatment of BTcP" ¹ and, of these, 55% (n=97) had read it in full. The level of understanding of each of the recommendations was greater than 90% in all cases, ranging between 90.6% for recommendation 2 (differential diagnosis) and 100% for recommendation 3 (specific treatment for BTcP) (Figure 2).

Fig. 2 Specialists' level of understanding of the recommendations. 

The level of specialists' compliance with the recommendations was very high for all of them (Figure 3). Recommendation 6, regarding prior use of opioids for baseline pain, was the recommendation that found least acceptance (56.4% of full and 35.6% partial compliance), followed by recommendation 2 regarding the differential diagnosis of BTcP and use of Davies' algorithm (72.3% with full compliance and 26.7% with partial compliance) and recommendation 10 regarding patient follow-up (78.7% with full compliance and 18.3% with partial compliance).

Fig. 3 Specialists' level of accordance with the recommendations about the management of BTcP (mean, 95% CI). 

Prior to the review of clinical records, all physicians considered that they "almost always" implemented each of the guideline recommendations (between 75% and 100% of times) or "normally" (between 50% and 75% of times), though with significant differences among items (Figure 4). The recommendations least frequently implemented were recommendation 10 (patient follow-up), where 59.4% of physicians reported "almost always" implementing it, and recommendations 5 (prevention of side effects) and 6 (prior use of opioids for baseline pain), where 66.3% and 66,8% of participants recorded that they "almost always" implemented them.

Fig. 4 Level of implementation of recommendations for BTcP management perceived by the specialists before the evaluation of the clinical records (self-audit). 

We analyzed whether the work place (PCU or PU) could influence the physicians' opinions. There were significant differences in the perception of implementing the recommendations in articles 10 (patient follow-up), 5 (prevention of side effects from the treatment) and 11 (health education of the patient/family on the pain and its management). For the three recommendations, the professionals who worked in PU reported they implemented them with lesser frequency than those who worked in CPU (p=0.001 in the three mentioned items) (Figure 5).

Fig. 5 Perceived level of implementation of recommendations based on the workplace before the self-assessment of clinical records (self-audit). 

The patients reviewed in the study during the evaluation of the CR by the physicians themselves (self-audit) had a mean of 3.1 (CI 95% = 2.9-3,2.) and a median of 3 episodes of BTcP per day (range 1-6). A total of 69% (627) of cases were patients with tumor origin. The intensity of the episode was classified as "moderate" in 22.5% of cases, "high" for 53% and "unbearable" for 22.5% of cases. The mean time taken to reach a peak of maximum pain was within 5.5 minutes, the median was 4 minutes, with a range between 0 seconds and 44 minutes. Regarding the physiopathology of the pain, 33% of cases had nociceptive origin, 16% were of neuropathic origin and 51% of mixed origin.

After the review of CR, the recommendations with a lesser level of implementation in actual practice were recommendation 5 regarding the prevention of side effects of the treatment, on average, in 15% of cases, and recommendation 10 regarding patient follow-up, with 18.5% of cases where its implementation was not recorded (Figure 6).

Fig. 6 Frequency of non-implementation of recommendations by the specialists after self-assessment of the clinical records (self-audit). 

DISCUSSION

BTcP is a very common problem among cancer patients ¹. European studies estimate that between 23% and 93% of cancer patients could be suffering it ². In Spain, in 2002, this type of pain was found in 41% of cancer patients attended in palliative care units ³a transitory exacerbation of pain superimposed on a background of persistent, usually adequately controlled pain, has been reported to occur in 50% to 75% of cancer patients. However, a 23% prevalence of BTP was recently reported in a study of Spanish patients with advanced cancers, showing probably a low detection rate of this clinical problem. The purpose of the present study was to determine the prevalence of BTP among oncology patients managed by palliative care teams in Catalonia, Spain, and to characterize the frequency, intensity, and treatment of BTP episodes. Sixty-two teams studied 397 patients on a predetermined index day. BTP was reported by 163 (41%. In a more recent study, a prevalence of 90% cancer patients was described ⁴. Emotional and sleep alterations, together with a limitation of higher functions, such as ability of concentration and thought, lead to a deterioration in quality of life and functional capacity of patients with BTcP. Additionally, they prevent the normal implementation of daily and working activities and interfere with personal relationships ^5,6,7,8.

The diagnosis of causes that give rise to BTcP and the evaluation of characteristics of its appearance in daily practice is, often, deficient and as a consequence its treatment may be sometimes inadequate ^2,4,9,10. However, the diagnosis and the evaluation of BTcP are not complex if there exists a high rate of suspicion and precise case history to make a correct differential diagnosis ^11,12,13,14. Furthermore, therapeutic possibilities have improved in recent years with the appearance of fentanyl administered through mucous surfaces, which are adjusted accurately to the requirements to immediately relieve the syndrome ¹⁵. Nevertheless, there is evidence that a large number of BTcP episodes are not detected correctly or are inappropriate and insufficient with non-selective drugs, nor recommended according to the available scientific knowledge¹. Additionally, some physicians and patients may have unjustified fear regarding the use of opioids in this context, which may lead to insufficient treatment ¹⁶. This situation has major repercussions on patients' quality of life and healthcare costs ¹⁷.

Our study shows that the professionals dedicated to attending to patients with BTcP know the recommendations for its proper management and that the level of compliance with them is very high. The questionnaires were answered by physicians, mostly from public health system, with an average of 12 years experience and a large number of patients with BTcP in their consultations, which may explain the high level of understanding and follow-up of the recommendations and, furthermore, strengthens the role of these guidelines drawn up by the SS involved in managing BTcP.

Nevertheless, it is important to point out the two recommendations that achieved a lesser degree of compliance a priori, before carrying out the evaluation of the CR or self-audit. These two recommendations with lesser compliance were recommendation 6 regarding the prior use of opioids for baseline pain which only obtained full compliance of 56%, and recommendation 2 regarding differential diagnosis of BTcP and use of Davies' algorithm, which obtained 72.3% of full compliance.

Furthermore, the general perception of specialists is that most recommendations are always implemented or almost always, but we should mention three recommendations that are perceived to be implemented with lesser frequency. These recommendations are 10 about the patient's follow-up (only 59.4% of physicians stated they almost always implement it), recommendation 5 regarding the prevention of side effects of the treatment (66.3% almost always implement it), and again, recommendation 6 regarding the prior use of opioids for baseline pain (only 66.8% almost always implement it).

Considering both recommendations with lower level of accordance and those recommendations perceived as the lesser implemented, recommendation 6 is highlighted. This recommendation, regarding the prior use of opioids for baseline pain, is one that reaches lower level of accordance and it is perceived as the lesser implemented.

In future editions of the guidelines for managing BTcP, it would be interesting to redraft the less accepted or less implemented recommendations, referring to differential diagnosis, baseline treatment of pain or side effects, and the follow-up of BTcP, to obtain the maximum consensus of specialists. There have also been differences in application of the recommendations among specialists that work in PU and in CPU, which could be an aspect to bear in mind in the future to adapt the recommendations to the field of professionals' performance.

After the self-audit of CR, the lesser implemented recommendations in actual clinical practice were 5 regarding the prevention of side effects of the treatment, and 10 regarding patient follow-up. In both cases, the attendance deficit described coincides with physicians' prior perception. However, regarding recommendation 6 on the use of opioids to control baseline pain, the analysis of actual practice revealed a significantly lower non-compliance (only 7% of cases) than expected, in accordance with professionals' prior self-audit (33.7% of physicians stated they had not implemented it systematically).

This work has certain limitations, characteristic of surveys and forms carried out electronically, among which we highlight the difficulty to clarify or nuance the individual opinions of participants ^18,19"uri":["http://www.mendeley.com/documents/?uuid=39a3d5d8-93a4-464c-ac76-fefdeddff2c5"],"itemData":{"DOI":"10.1046/j.1365-2923.2002.01312.x","ISBN":"0308-0110 (Print. Additionally, the opinions provided by the participants may not necessarily reflect the majority opinion of professionals of the whole territory that can include physicians with less work experience or a smaller number of patients with BTcP.

In short, most PU and CPU professionals understand, support and imlpement the recommendations of the SS on managing BTcP. They also have a realistic, accurate perception of the quality of their work, as well as of the aspects to be improved in their daily practice as regards the recommendations based on scientific evidence. In future updates to the guidelines for managing BTcP, the lesser accepted or implemented recommendations could be re-drafted or refined, in order to achieve broader compliance among professionals in different working environments. The diffusion and implementation of the recommendations may improve the clinical results of managing BTcP, rationalizing clinical decisions and reducing the unjustified variability of habits by means of a correct diagnosis, follow-up and treatment of BTcP.