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Zolpidem use and risk of fracture in elderly insomnia patients.

Kang DY, Park S, Rhee CW, Kim YJ, Choi NK, Lee J, Park BJ - J Prev Med Public Health (2012)

Bottom Line: Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the case-crossover design.Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis.Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup.

View Article: PubMed Central - PubMed

Affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, Korea.

ABSTRACT

Objectives: To evaluate the risk of fractures related with zolpidem in elderly insomnia patients.

Methods: Health claims data on the entire South Korean elderly population from January 2005 to June 2006 were extracted from the Health Insurance Review and Assessment Service database. We applied a case-crossover design. Cases were defined as insomnia patients who had a fracture diagnosis. We set the hazard period of 1 day length prior to the fracture date and four control periods of the same length at 5, 10, 15, and 20 weeks prior to the fracture date. Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the case-crossover design. Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis. The odds ratios and their 95% confidence intervals (CIs) were estimated for the risk of fracture related to zolpidem.

Results: One thousand five hundred and eight cases of fracture were detected in insomnia patients during the study period. In our data, the use of zolpidem increased the risk of fracture significantly (adjusted odds ratio [aOR], 1.72; 95% CI, 1.37 to 2.16). However, the association between benzodiazepine hypnotics and the risk of fracture was not statistically significant (aOR, 1.00; 95% CI, 0.83 to 1.21). Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup.

Conclusions: Zolpidem could increase the risk of fracture in elderly insomnia patients. Therefore zolpidem should be prescribed carefully and the elderly should be provided with sufficient patient education.

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Related in: MedlinePlus

Control of study period. 1Subjects should have more than one hypnotic prescription and no stroke history within this 180 days.
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Figure 3: Control of study period. 1Subjects should have more than one hypnotic prescription and no stroke history within this 180 days.

Mentions: For the purpose of analysis, it was imperative that we confirmed the drug exposure information up to 141 days prior to the day the patient had a fracture, and we only targeted the cases that occurred in a specific year (from July 1, 2005 to June 30, 2006). We excluded patients from analysis targets who experienced a fracture before July 1, 2005, because we could not secure enough drug exposure information during the control period. In order to obtain information on the drugs that a patient took in a particular month, the data on fees charged in the previous month was required. So we ensured that the earliest control period of the patient did not earlier than in February of 2005. For example, if there is a patient who was prescribed a medicine called 'A' for 30 days on December 31, 2004, with only the charge data of January of 2005, it could appear as if the patient was not exposed to 'A' even though he or she was exposed until January 30, 2005. In particular, if the prescribed period was long, this problem could become worse, but in the case of the sleeping pill, which was the target of our research, every prescription period was less than 30 days, so we did not include in our research period the month that did not cover the hospital statement data up to 30 days and so forth. Therefore, in January of 2005, without establishing the control period and by collecting only the drug prescription data, we obtained the necessary data for a control period of February, 2005 (Figure 3).


Zolpidem use and risk of fracture in elderly insomnia patients.

Kang DY, Park S, Rhee CW, Kim YJ, Choi NK, Lee J, Park BJ - J Prev Med Public Health (2012)

Control of study period. 1Subjects should have more than one hypnotic prescription and no stroke history within this 180 days.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3412984&req=5

Figure 3: Control of study period. 1Subjects should have more than one hypnotic prescription and no stroke history within this 180 days.
Mentions: For the purpose of analysis, it was imperative that we confirmed the drug exposure information up to 141 days prior to the day the patient had a fracture, and we only targeted the cases that occurred in a specific year (from July 1, 2005 to June 30, 2006). We excluded patients from analysis targets who experienced a fracture before July 1, 2005, because we could not secure enough drug exposure information during the control period. In order to obtain information on the drugs that a patient took in a particular month, the data on fees charged in the previous month was required. So we ensured that the earliest control period of the patient did not earlier than in February of 2005. For example, if there is a patient who was prescribed a medicine called 'A' for 30 days on December 31, 2004, with only the charge data of January of 2005, it could appear as if the patient was not exposed to 'A' even though he or she was exposed until January 30, 2005. In particular, if the prescribed period was long, this problem could become worse, but in the case of the sleeping pill, which was the target of our research, every prescription period was less than 30 days, so we did not include in our research period the month that did not cover the hospital statement data up to 30 days and so forth. Therefore, in January of 2005, without establishing the control period and by collecting only the drug prescription data, we obtained the necessary data for a control period of February, 2005 (Figure 3).

Bottom Line: Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the case-crossover design.Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis.Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup.

View Article: PubMed Central - PubMed

Affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, Korea.

ABSTRACT

Objectives: To evaluate the risk of fractures related with zolpidem in elderly insomnia patients.

Methods: Health claims data on the entire South Korean elderly population from January 2005 to June 2006 were extracted from the Health Insurance Review and Assessment Service database. We applied a case-crossover design. Cases were defined as insomnia patients who had a fracture diagnosis. We set the hazard period of 1 day length prior to the fracture date and four control periods of the same length at 5, 10, 15, and 20 weeks prior to the fracture date. Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the case-crossover design. Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis. The odds ratios and their 95% confidence intervals (CIs) were estimated for the risk of fracture related to zolpidem.

Results: One thousand five hundred and eight cases of fracture were detected in insomnia patients during the study period. In our data, the use of zolpidem increased the risk of fracture significantly (adjusted odds ratio [aOR], 1.72; 95% CI, 1.37 to 2.16). However, the association between benzodiazepine hypnotics and the risk of fracture was not statistically significant (aOR, 1.00; 95% CI, 0.83 to 1.21). Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup.

Conclusions: Zolpidem could increase the risk of fracture in elderly insomnia patients. Therefore zolpidem should be prescribed carefully and the elderly should be provided with sufficient patient education.

Show MeSH
Related in: MedlinePlus