Actual Patient Population Research Articles

Experience with anxiety and depression treatment studies: implications for designing irritable bowel syndrome clinical trials

This report highlights various considerations regarding the potential effects of concurrent psychiatric conditions and a history of abuse in patient volunteers for clinical trials in irritable bowel syndrome (IBS). Even though many studies have used psychological rating scales to assess personality and psychological traits of patients with IBS, the prevalence of the different psychiatric diagnoses (i.e., categorical assessment) in patients with IBS has only recently been assessed systematically. Recent studies of treatment-seeking patients have indicated that the majority of individuals (50% to 90%) who seek treatment for IBS have a lifetime history or currently have one or more common psychiatric conditions: major depressive disorder, generalized anxiety disorder, panic disorder, social phobia, somatization disorder, and posttraumatic stress disorder. Traditional clinical wisdom is that the presence of a psychiatric disorder increases the likelihood that an IBS patient will seek treatment. However, recent data suggest that IBS and psychiatric disorders are associated regardless of treatment-seeking status. Patients with psychiatric disorders should be included in clinical IBS studies, because this reflects the actual patient population. Extrapolating from the psychiatric literature, inclusion of patients with IBS with mild to moderate anxiety or depression is warranted.

An optimal dual-size vial system for the cost-effective usage of Adenoscan

Background. Adenoscan (Fujisawa USA, Inc., Deerfield, Ill.) has been initially packaged in a 30 ml glass vial for single use only because it contains no preservative. This restricted usage has generated considerable waste and high cost for the patient. Although the new 20 ml vial of Adenoscan provides some reduction in waste, the savings offered by the 20 ml and 30 ml vial system is still not optimal. The purpose of this study was to investigate an optimal dual-size vial system that would provide limited amounts of waste while maintaining its practicality to satisfy different patient populations. Materials and Results. The least waste for each potential combination ( n = 344) of two vials was calculated by assuming that patient weights (30 to 200 kg) follow a normal distribution. The 6 ml and 15 ml vial combination had the least expected waste for lighter patient populations, and the 9 ml and 15 ml vial system had the least expected waste for heavier populations. The calculated wastes for 4207 patients (83 ± 19 kg) undergoing adenosine stress myocardial perfusion studies at the Mayo Clinic were 10.5 ± 9.3 ml (30 ml vial), 5.1 ± 2.9 ml (20 ml and 30 ml vial system), 1.6 ± 1.0 ml (6 ml and 15 ml vial system), and 1.8 ± 1.2 ml (9 ml and 15 ml vial system). Conclusions. In general, both the 6 ml and 15 ml and 9 ml and 15 ml vial systems perform better than either the single 30 ml vial or the 20 ml and 30 ml vial system. Furthermore, the 6 ml and 15 ml vial combination offers the lowest expected waste for the actual patient population that underwent the adenosine stress myocardial perfusion imaging studies at our institution.

Depot antipsychotic drugs. Place in therapy.

The pharmacokinetics of depot antipsychotic medications are such that an intramuscular injection given at intervals of from 1 to 4 weeks will produce adequate plasma concentrations that are sufficient to prevent relapse over the dosage interval. Such medication is useful in patients who do not reliably take their oral medication. The pharmacokinetics and clinical actions of various depot formulations of antipsychotic drugs have been extensively studied. Unfortunately, patients who do not reliably take their oral medications are unlikely to volunteer for controlled studies. This is because the same factors that influence a patient to not cooperate with the physician in taking the medication as prescribed will also interfere with their willingness to volunteer for research protocols. Thus, evidence from blinded controlled trials may not necessarily reflect the actual patient population at risk. We feel that particularly important evidence of efficacy of depot vs oral medication comes from mirror-image studies. In these trials, the number of hospitalisations after initiation of depot medication is compared with that observed when the patient was solely taking oral medication. Studies of this type show that depot medication substantially reduces the rate of relapse. There is considerable evidence about how long depot medications should be used. For many patients, depot medication to prevent relapse in schizophrenia should be used for the life of the patient. As the conventional antipsychotic agents are replaced by a new generation of agents, the need for depot formulations will continue, and the knowledge gained about the current formulations should transfer to future generations of drugs.

Author Response

We would like to thank Ms Michlovitz for her thoughtful and insightful comments. Ms Michlovitz accurately notes that there are some obvious limitations in using a model of delayed-onset muscle soreness (DOMS) to study the effects of salicylate phonophoresis. There is no question that research on the effects of physical agents must ultimately include studies on actual patient populations. We maintain, however, that DOMS is an attractive model for obtaining preliminary information on the effectiveness of salicylate phonophoresis. Ms Michlovitz makes the statement that “models for studies should be analogous to those actually representing clinical populations.” Although DOMS is not identical to other conditions, this model is indeed analogous to conditions that exhibit an inflammatory response leading to musculoskeletal pain and stiffness. The idea that acute inflammation appears to be the mechanism underlying DOMS was reinforced recently by Smith.1

692 QUANTITATIVE COMPUTERIZED ANALYSIS OF HOUSE-STAFF TRAINING

The larger number of Pediatric residents and the consequent relative decrease in patient population have made it more likely that a resident may not care for an adequate number of patients during his training. At the same time, increased departmental specialization may result in a biased selection of patients managed by a resident.We have developed a Fortran IV program for use with the CDC Cyber 171 computer that records the actual patient population for each resident during his general inpatient experience. The information is collected directly from the supervising residents and is verified with hospital admission and occupancy records. Each patient is listed by his primary diagno sis, chart number, age, sex, dates of admission and discharge and month of care. The patients are sorted by diagnosis providing a cumulative record of the number and variety of patients managed by each resident. The age distribution and daily patient load are calculated and charts are retrievable for review. On our service, a PL-1 typically admitted 30 new inpatients a month and had a daily patient load of 8.4.A resident's individual record is compared to the total patient population of the inpatient service as constructed in this program. Deviations in experience from the complete service and obvious deficiencies are identified. Resident elective time is structured to compensate for these variations. The system is adaptable to register OPD, ER and nursery patients for similar analysis. This record of experience can be combined with monthly subjective faculty assessments and results of the ABP In-Training Examination to accomplish a thorough evaluation of each resident.