Diagnostic Performance of Self-Assessment for Constipation in Patients With Long-Term Opioid Treatment

Constipation is a prevalent comorbidity affecting ∼50% of patients with long- term opioid therapy. In clinical routine different diagnostic instruments are in use to identify patients under risk. The aim of this study was to assess the diagnostic performance of an 11-item Likert scale for constipation used as a self-assessment in opioid-treated patients. This trial was conducted as a retrospective cohort study in Berlin, Germany. Patients with long-term opioid therapy treated in 2 university-affiliated outpatient pain facilities at the Charité hospital were included from January 2013 to August 2013. Constipation was rated in a self-assessment using a numeric rating scale from 0 to 10 (Con- NRS) and compared with results from a structured assessment based on ROME-III criteria. Altogether, 171 patients were included. Incidence of constipation was 49% of patients. The receiver-operating characteristic of Con-NRS achieved an area under the curve of 0.814 (AUC 95% confidence interval 0.748–0.880, P < 0.001). Con-NRS ≥ 1 achieved sensitivity and specificity of 79.7% and 77.2%, respectively. The positive predictive value and the negative predictive value were 70.3% and 81.6%, respectively. Overall diagnostic performance of a concise 11-item Likert scale for constipation was moderate. Although patients with long-term opioid therapy are familiar with numeric rating scales, a significant number of patients with constipation were not identified. The instrument may be additionally useful to facilitate individualized therapeutic decision making and to control therapeutic success when measured repetitively

Retrospective cohort study of opioid-induced constipation and laxative use in chronic pain patients

Einleitung: Die Verordnung von Opioiden hat in den letzten Jahren stark zugenommen. Dies führt ebenfalls zu einer Zunahme von Obstipationen, die eine häufige unerwünschte Arzneimittelwirkung von Opioiden darstellen. Die Intention der vorliegenden Studie war es, die Obstipationsprävalenz bei einer Studienpopulation mit ambulanter Opioidtherpapie festzustellen und mögliche Risikofaktoren zu bewerten. Methoden: Es wurde eine retrospektive Kohortenstudie an zwei Schmerzambulanzen der Charité Universitätsmedizin Berlin durchgeführt, bei der alle chronischen Schmerzpatienten, die seit mindestens 4 Wochen im Zeitraum Januar 2013 bis August 2013 ambulant mit oralen oder transdermalen Opioiden behandelt wurden, eingeschlossen wurden. Die Rom-III-Kriterien dienten zur Definition von Obstipation. Ergebnisse: 171 aus 1166 untersuchten Patienten wurden insgesamt eingeschlossen. Die Dosis des täglich verabreichten oralen Morphinäquivalentes betrug im Median 90 mg, die Behandlungsdauer lag im Median bei 5 Jahren. Zu den am häufigsten angegebenen Schmerzursachen zählten Rücken-, muskuloskelettale und neuropathische Schmerzen. Die Obstipationsprävalenz betrug insgesamt 49%, wobei 35% durch regelmäßige Laxanseinnahme beschwerdefrei waren und 14% unter dem klinischen Bild einer Obstipation litten. 51% des Patientenkollektivs waren auch ohne Laxansgebrauch zum Studienzeitpunkt symptomfrei. Das Obstipationsrisiko stieg signifikant mit steigendem Patientenalter (OR 1,036, p=0,009) und steigender Dosis an oralem Morphinäquivalent (OR 1,007, p=0,004). Die Faktoren Geschlecht, Applikationsart, Dauer der Opioidtherapie und untersuchte Koanalgetika hatten keinen signifikanten Einfluss auf das Risiko. Diskussion: Obwohl Obstipationen weiterhin eine bedeutende Rolle bei den Opioid- induzierten Nebenwirkungen spielen, war dennoch etwa die Hälfte der untersuchten Stichprobe zum Studienzeitpunkt nicht davon betroffen. Daher sollte für jeden Patienten ein eigener bedarfsadaptierter Therapieplan entworfen werden, der auch die Bedürfnisse und Wünsche des Patienten im Sinne einer partizipativen Entscheidungsfindung berücksichtigt.Introduction: The number of opioid prescriptions has strongly increased within the last years. This leads to an increase in constipations which represent a common side effect of opioids. The goal of this study was to determine the prevalence of constipation in a study population of outpatient opioid therapy and the evaluation of possible risk factors. Methods: A retrospective cohort study was carried out at two outpatient pain clinics of the Charité University Berlin. All patients were included who were treated for chronic pain with oral or transdermal opioids for at least 4 weeks within the time period of January until August 2013. Rome III criteria were applied to define constipation. Results: 171 out of 1166 screened patients were included in the trial. The median of daily morphine equivalent dose was 90 mg. The median of the duration of opioid therapy was 5 years. The most frequently named reasons for chronic pain therapy were back pain, as well as musculoscelettal and neuropathic pain. The overall prevalence of constipation was 49%, whereas 35% could manage their symptoms by using laxatives and 14% showed clinical symptoms of constipation. 51% of patients were free of symptoms even without laxative use at the time of data collection. The risk of constipation rose significantly with increasing patient age (OR 1.036, p=0.009) and increasing daily morphine equivalent dose (OR 1.007, p=0.004). Gender, route of administration, duration of opioid therapy and investigated co-analgesics had no significant influence. Discussion: Even though constipation plays still an important role among opioid induced side effects, half of the investigated population was not affected by constipation at time of data collection. Therefore, an individualized medication plan should be designed for each patient that takes into account the requirements and wishes of the patient in terms of participative decision making