Biomedical subjects

Stacy R Lindborg

Publications and source records attributed to Stacy R Lindborg.

7 recordsLinked to original sources

PubMed2006

Multiple imputation techniques in small sample clinical trials.

Clinical trials allow researchers to draw conclusions about the effectiveness of a treatment. However, the statistical analysis used to draw these conclusions will inevitably be complicated by the common problem of attrition. Resorting to ad hoc methods such as case deletion or mean imputation can lead to biased results, especially if the amount of missing data is high. Multiple imputation, on the other hand, provides the researcher with an approximate solution that can be generalized to a number of different data sets and statistical problems. Multiple imputation is known to be statistically valid when n is large. However, questions still remain about the validity of multiple imputation for small samples in clinical trials. In this paper we investigate the small-sample performance of several multiple imputation methods, as well as the last observation carried forward method.

Bayes Theorem↗

PubMed2003

Randomized trial of olanzapine versus placebo in the symptomatic acute treatment of the schizophrenic prodrome.

BACKGROUND: The prodromal phase of schizophrenic disorders has been described prospectively. The present study aimed to determine the short-term efficacy and safety of olanzapine treatment of prodromal symptoms compared with placebo. METHODS: This was a double-blind, randomized, parallel-groups, placebo-controlled trial with fixed-flexible dosing conducted at four sites. Sixty patients met prodromal diagnostic criteria, including attenuated psychotic symptoms, as determined by structured interviews. Olanzapine 5-15 mg daily or placebo was prescribed for 8 weeks. RESULTS: In the mixed-effects, repeated-measures analysis, the treatment x time interaction for the change from baseline on the Scale of Prodromal Symptoms total score was statistically significant, and post hoc analyses revealed that the olanzapine-placebo difference reached p<.10 by week 6 and p<.05 at week 8. Ratings of extrapyramidal symptoms remained low in each group and were not significantly different. Olanzapine patients gained 9.9 lb versus.7 lb for placebo patients (p<.001). CONCLUSIONS: This short-term analysis suggests olanzapine is associated with significantly greater symptomatic improvement but significantly greater weight gain than is placebo in prodromal patients. Extrapyramidal symptoms with olanzapine were minimal and similar to those with placebo. Future research over the longer term with more patients will be needed before recommendations can be made regarding routine treatment.

Adolescent↗

PubMed2003

Effects of intramuscular olanzapine vs. haloperidol and placebo on QTc intervals in acutely agitated patients.

Prolongation of the QTc interval has been reported during treatment with oral antipsychotic agents and may be more pronounced during parenteral administration. Pooled QTc interval data from acutely agitated patients across four double-blind trials were compared. Databases included: placebo-controlled [two schizophrenia, one bipolar mania trials (n=565)]; haloperidol-controlled [two schizophrenia trials (n=482)]; geriatric placebo-controlled [1 dementia trial (n=204)]. Patients received 1-3 injections of intramuscular (IM) olanzapine (2.5-10 mg/injection), IM haloperidol (7.5 mg/injection), or IM placebo. At 2 and 24 h after IM olanzapine treatment, the mean QTc interval decreased approximately 3 ms from baseline in the placebo- and haloperidol-controlled databases. When there was a statistically significant difference between IM olanzapine and IM placebo, QTc intervals decreased during treatment with IM olanzapine and increased with IM placebo. The incidences of prolonged (endpoint >/=99th percentile of healthy adults or >/=500 ms) or lengthened (increase >/=60 ms) QTc intervals during treatment with IM olanzapine (<3% placebo- and haloperidol-controlled databases, <12% geriatric placebo-controlled database) were never significantly greater than with comparators. These data suggest that IM olanzapine has a favorable QTc interval profile in acutely agitated patients with schizophrenia, bipolar mania, or dementia.

Antipsychotic Agents↗

PubMed2003

Procedural learning in schizophrenia after 6 months of double-blind treatment with olanzapine, risperidone, and haloperidol.

RATIONALE: First generation antipsychotics induce extrapyramidal motor symptoms (EPS), presumably through dopamine D(2) receptor blockade at the dorsal striatum. This may also produce impairment of cognitive processes, such as procedural learning, that are dependent on this region. Haloperidol and, to a lesser extent, risperidone, are active in the dorsal striatum and may induce EPS and impairment of procedural learning. In contrast, the prototypical second-generation antipsychotic, clozapine, is less active in the dorsal striatum and does not induce EPS or impair procedural learning. Olanzapine is pharmacologically similar to clozapine and has a low incidence of EPS induction. OBJECTIVES: To assess the hypothesis that olanzapine would not have a deleterious effect on procedural learning. METHODS: Thirty-nine subjects with early phase schizophrenia were randomly assigned to double blind treatment with haloperidol, risperidone, or olanzapine. They were administered the Tower of Toronto test at an unmedicated baseline and again following 6 weeks and 6 months of treatment. RESULTS: Procedural learning, defined as the improvement observed between two blocks of five trials of the Tower of Toronto, was preserved after 6 weeks of all three treatments but showed a substantial decline after 6 months of treatment with haloperidol or risperidone. CONCLUSIONS: These data are consistent with the differential activity of the three medications in dorsal striatum structures and suggest that the advantages of olanzapine over haloperidol and risperidone in relation to extrapyramidal syndromes may also generalize to procedural learning. The results also suggest that the procedural learning disadvantages of haloperidol and risperidone accrue slowly but are apparent after 6 months of treatment.

Adolescent↗

PubMed2003

A comparison of the efficacy and safety of olanzapine versus haloperidol during transition from intramuscular to oral therapy.

BACKGROUND: Acutely agitated patients with schizophrenia who receive intramuscular (IM) medications typically are switched to oral (PO) antipsychotic maintenance therapy. OBJECTIVE: The goal of this study was to assess the efficacy and safety of olanzapine versus those of haloperidol during transition from IM to PO therapy. We used additional data from a previously reported trial to test the hypothesis that the reduction in agitation achieved by IM olanzapine 10 mg or IM haloperidol 7.5 mg would be maintained following transition to 4 days of PO olanzapine or PO haloperidol (5-20 mg/d for both). We also hypothesized that olanzapine would maintain its more favorable extrapyramidal symptom (EPS) safety profile. METHODS: This was a multinational (hospitals in 13 countries), double-blind, randomized, controlled trial. Acutely agitated inpatients with schizophrenia were treated with 1 to 3 IM injections to olanzapine 10 mg or haloperidol 7.5 mg over 24 hours and were entered into a 4-day PO treatment period with the same medication (5-20 mg/d for both). The primary efficacy measurement was reduction in agitation, as measured by the Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) score. Adverse events and scores on EPS rating scales were assessed. RESULTS: A total of 311 patients (204 men, 107 women; mean [SD] age, 38.2 [11.6] years) were enrolled (131, 126, and 54 patients in the olanzapine, haloperidol, and placebo groups, respectively). In all, 93.1% (122/131) of olanzapine-treated patients and 92.1% (116/126) of haloperidol-treated patients completed the IM period and entered the PO period; 85.5% (112/131) of olanzapine-treated patients and 84.1% (106/126) of haloperidol-treated patients completed the PO period. IM olanzapine and IM haloperidol effectively reduced agitation over 24 hours (mean [SD] PANSS-EC change, -7.1 [4.81 vs -6.7 [4.3], respectively). Reductions in agitation were sustained throughout the PO period with both study drugs (mean [SD] change from PO period baseline, -0.6 [4.8] vs -1.3 [4.4], respectively). During PO treatment, haloperidol-treated patients spontaneously reported significantly more acute dystonia than olanzapine-treated patients (4.3%[5/116] vs 0% [0/122], respectively; P = 0.026) and akathisia (5.2% [6/116] vs 0% [0/122], respectively; P = 0.013). Significantly more haloperidol-treated patients than olanzapine-treated patients met categorical criteria for treatment-emergent akathisia (18.5% [17/92] vs 6.5% [7/107], respectively; P = 0.015). CONCLUSIONS: In the acutely agitated patients with schizophrenia in this study, both IM olanzapine 10 mg and IM haloperidol 7.5 mg effectively reduced agitation over 24 hours. This alleviation of agitation was sustained following transition from IM therapy to 4 days of PO treatment (5-20 mg/d for both). During the 4 days of PO treatment, olanzapine-treated patients did not spontaneously report any incidences of acute dystonia, and olanzapine had a superior EPS safety profile to that of haloperidol. The combination of IM and PO olanzapine may help improve the treatment of acutely agitated patients with schizophrenia.

Administration, Oral↗

PubMed2003

Calming versus sedative effects of intramuscular olanzapine in agitated patients.

Distinct calming rather than nonspecific sedation is desirable for the treatment of acute agitation. In 3 double-blind studies, acutely agitated patients with schizophrenia (N = 311), bipolar mania (N = 201), or dementia (N = 206) were treated with intramuscular (1-3 injections/24 hrs) olanzapine (2.5-10.0 mg), haloperidol (7.5 mg), lorazepam (2.0 mg), or placebo. The Agitation-Calmness Evaluation Scale (ACES; Eli Lilly and Co.) and treatment-emergent adverse events assessed sedation. Across all studies, 1 patient (lorazepam-treated, bipolar) became unarousable. There were no significant between-group differences in ACES scores of deep sleep or unarousable at any time across. Excluding asleep patients, agitation remained significantly more reduced with olanzapine than placebo (P <.05). The incidences of adverse events indicative of sedation were not significantly different with olanzapine versus comparators. For the treatment of acute agitation associated with schizophrenia, bipolar mania, or dementia, intramuscular olanzapine-treated patients experienced no more sedation than haloperidol- or lorazepam-treated patients and experienced distinct calming rather than nonspecific sedation.

Adult↗

PubMed2003

Intramuscular olanzapine and intramuscular haloperidol in acute schizophrenia: antipsychotic efficacy and extrapyramidal safety during the first 24 hours of treatment.

OBJECTIVE: To determine the antipsychotic efficacy and extrapyramidal safety of intramuscular (i.m.) olanzapine and i.m. haloperidol during the first 24 hours of treatment of acute schizophrenia. METHOD: Patients (n = 311) with acute schizophrenia were randomly allocated (2:2:1) to receive i.m. olanzapine (10.0 mg, n = 131), i.m. haloperidol (7.5 mg, n = 126), or i.m. placebo (n = 54). RESULTS: After the first injection, i.m. olanzapine was comparable to i.m. haloperidol and superior to i.m. placebo for reducing mean change scores from baseline on the Brief Psychiatric Rating Scale (BRPS) Positive at 2 hours (-2.9 olanzapine, -2.7 haloperidol, and -1.5 placebo) and 24 hours (-2.8 olanzapine, -3.2 haloperidol, and -1.3 placebo); the BPRS Total at 2 hours (-14.2 olanzapine,-13.1 haloperidol, and -7.1 placebo) and 24 hours (-12.8 olanzapine, -12.9 haloperidol, and -6.2 placebo); and the Clinical Global Impressions (CGI) scale at 24 hours (-0.5 olanzapine, -0.5 haloperidol, and -0.1 placebo). Patients treated with i.m. olanzapine had significantly fewer incidences of treatment-emergent parkinsonism (4.3% olanzapine vs 13.3% haloperidol, P = 0.036), but not akathisia (1.1% olanzapine vs 6.5% haloperidol, P = 0.065), than did patients treated with i.m. haloperidol; they also required significantly less anticholinergic treatment (4.6% olanzapine vs 20.6% haloperidol, P < 0.001). Mean extrapyramidal symptoms (EPS) safety scores improved significantly from baseline during i.m. olanzapine treatment, compared with a general worsening during i.m. haloperidol treatment (Simpson-Angus Scale total score mean change: -0.61 olanzapine vs 0.70 haloperidol; P < 0.001; Barnes Akathisia Scale global score mean change: -0.27 olanzapine vs 0.01 haloperidol; P < 0.05). CONCLUSION: I.m. olanzapine was comparable to i.m. haloperidol for reducing the symptoms of acute schizophrenia during the first 24 hours of treatment, the efficacy of both being evident within 2 hours after the first injection. In general, more EPS were observed during treatment with i.m. haloperidol than with i.m. olanzapine.

Acute Disease↗