Table 5Strengths and Limitations of Non-Randomized Studies Using the Downs and Black Checklist15

StrengthsLimitations
Isbister et al. 201719
  • The objective of the study, main outcomes to be measured, characteristics of the included patients, and main findings were clearly described
  • Estimates of random variability were provided for continuous outcomes
  • Study patients were representative of patients admitted to a single hospital for clonidine overdose or poisoning
  • All analyses were pre-specified in the methods section
  • Main outcome measures were valid and reliable
  • Estimates of random variability in dichotomous outcomes were not provided
  • Actual P values were not reported for all linear regression analyses
  • Unclear whether linear regression analysis was appropriate for associations with dose
  • Linear regression analysis did not adjust for confounders
Detweiler et al. 201617
  • The objective of the study, main outcome to be measured, characteristics of the included patients, and main findings were clearly described
  • Study patients were representative of veterans and active duty soldiers prescribed medication for PTSD combat nightmares ata single centre
  • Estimates of random variability were not provided for the main outcome
  • Adverse events were not reported
  • Retrospective chart review without a control group or statistical analyses
  • Some patients underwent more than one medication trial; trials were not independent of one another
  • Treatment compliance was not reported
  • Treatment response was not assessed using a valid and reliable instrument
Mannelli et al. 201318
  • The main outcomes to be measured, characteristics of included patients, and interventions of interest were clearly described
  • Adverse events were assessed (no list provided)
  • The post-hoc nature of the analysis was clearly stated
  • Follow-up period was the same for all patients
  • Statistical tests used to assess the main outcomes were appropriate
  • Main outcome measures used were valid and reliable
  • Patients were recruited from the same population and were in different intervention groups
  • The hypotheses of the study and main finding were not clearly described
  • A list of principal confounders was not provided
  • Effect sizes and simple outcome data were not reported
  • Estimates of random variability were not provided for the main outcomes
  • Numbers and characteristics of patients lost to follow-up was not described for each group
  • Actual P values were not reported
  • Study patients were not representative of patients in the original study as they represented only one centre
  • The staff and facility are not representative of treatment for smoking cessation alone (but may be representative of treatment for opioid addiction)
  • There was not adequatead justment for confounding in the analyses
  • It is unclear whether the study had sufficient power to detect differences between treatment groups

PTSD = post-traumatic stress disorder.

From: Clonidine for the Treatment of Psychiatric Conditions and Symptoms: A Review of Clinical Effectiveness, Safety, and Guidelines

Cover of Clonidine for the Treatment of Psychiatric Conditions and Symptoms: A Review of Clinical Effectiveness, Safety, and Guidelines
Clonidine for the Treatment of Psychiatric Conditions and Symptoms: A Review of Clinical Effectiveness, Safety, and Guidelines [Internet].
Chiu S, Campbell K.
Copyright © 2018 Canadian Agency for Drugs and Technologies in Health.

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