Breakthrough PainAdministration, BuccalFentanylAnalgesics, OpioidPainLabor PainPain MeasurementAnalgesicsPain ManagementPharmaceutical PreparationsDrug Dosage CalculationsDrug MonitoringChronic PainAnalgesia, EpiduralPain, PostoperativeTreatment OutcomePain, IntractablePrescription Drug MisuseDouble-Blind MethodDose-Response Relationship, DrugNeoplasmsChronic DiseaseArthralgiaMedication ErrorsMedication AdherenceNeuralgiaPalliative CareQuestionnairesProspective StudiesAnti-Inflammatory Agents, Non-SteroidalPain ThresholdRetrospective StudiesRadionuclide GeneratorsTime FactorsLow Back PainBack PainSeverity of Illness IndexQuality of LifePatient SatisfactionFollow-Up StudiesAbdominal PainNeck PainMedication SystemsComorbidityMedication ReconciliationMedication Systems, HospitalCohort StudiesPelvic PainPain PerceptionGene DosageFacial Pain