Determinants of change in the intention to use benzodiazepines

OBJECTIVE

To examine attitudes and beliefs associated with changes in the intention to use benzodiazepines during the six-month period after first benzodiazepine use.

DESIGN

Population-based 6-month follow-up with 3 measurement points (baseline, 2 weeks after inclusion, 6 months after inclusion).

SETTING

Starting or initial benzodiazepine users were included during a period of 4 months from November 1994 in the only pharmacy of a Dutch community of 13,500 people.

MEASURES

Variables proposed by the Model of Planned Behaviour and the Health Belief Model. Drug exposure data from automated pharmacy records.

RESULTS

At baseline, the intention to use benzodiazepines was primarily predicted by the perceived norm of the general practitioner regarding benzodiazepine use, and by the participants' own attitudes. After fourteen days, the determinants of change in the intention to use benzodiazepines were the initially perceived norm of the general practitioner and the change in the severity of participants' illnesses. After six months, the change in the severity of the illness and the perceived health benefits of benzodiazepines at the time of inclusion were the main determinants of the change in the intention to use benzodiazepines between the second and third measurement point. The intention to use benzodiazepines showed a decrease during follow-up. The three intention measures were significant predictors of actual benzodiazepine use during the year following baseline assessment.

CONCLUSION

The study sheds light on interesting determinants of decrease or increase in the intention to use during the six-month period after first benzodiazepine use.

Characteristics of current benzodiazepine users as indicators of differences in physical and mental health

The relationship between characteristics of benzodiazepine exposure and health-status was examined in order to investigate risk profiles of benzodiazepine users. In the only pharmacy of a Dutch community of 13,500 inhabitants, all current benzodiazepine users that presented with a benzodiazepine prescription in November 1994 were invited to participate. On the basis of the RAND-36 questionnaire, summary scores for both physical and mental health were calculated, the Physical Component Summary (PCS) and the Mental Component Summary (MCS). After dichotomization with a cut-off point indicating seriously impaired health and after the combination of the PCS and MCS, four different categories of health status could be identified. We used logistic regression to study the relation between these four different groups with respect to benzodiazepine exposure. In total a group of 360 current benzodiazepine users was studied. Results showed that almost one-third of the participants had no significant impaired health; this group was further classified as reference group. We classified three other groups: one with physical problems (31%), one with mental problems (18%), and one with a combination of the two (22%). Multivariate analysis showed differences in risk factors for an impaired health status. The group with impaired physical health was associated with self-reported indication for muscle relaxation, hypnotic use, and a high CDS (Chronic Disease Score). The group with impaired mental health was associated with more frequent consulting of a mental health care specialist and with a low sense of self-efficacy. The group with both impaired physical as well as mental health was associated with a higher incidence of widowhood, a lower sense of self-efficacy, a high CDS, using benzodiazepines more than prescribed, and reporting depression as reason for their benzodiazepine use. In particular, two groups need critical examination: a group of apparently healthy users with long-term benzodiazepine use; and a frail group with impaired physical and mental health and using a higher dose than prescribed. Patient counseling and management of these four groups can be tailored to the specific needs of each group.

Bacterial and viral removal efficiency, heat and moisture exchange properties of four filtration devices

Four devices used for filtration of microorganisms and/or for heating and moistening the ventilated air during mechanical ventilation were evaluated. This evaluation included measurement of bacterial and viral removal efficiency, heat and moisture exchange properties, dead space and air flow resistance. The devices included: Pall BB50T and DAR Sterivent (filtration devices); DAR Hygrobac and Gibeck Humid-vent [heat and moisture exchangers (HMEs)]. The two devices which are primarily conceived as filters, had the highest bacterial and viral removal efficiency (titre reduction of 10(5)-10(6) for bacteria and of 10(4)-10(5) for viruses), while removal efficiencies of the HME devices were lower: titre reduction of 10(4) for bacteria and 10(1)-10(3) for viruses. As expected, heat and moisture output of HMEs was better than that of filters. In mechanical ventilation, dead space and air flow resistance are important properties of devices, which might disturb efficient ventilation. There were only minor differences in dead space and air flow resistance. Resistance to airflow in the HMEs was increased by nebulization of medication (mesna) unlike that of the filters.

Airborne gram-negative bacteria and endotoxin in sick building syndrome. A study in Dutch governmental office buildings

METHODS

During a survey of building-related symptoms among 1355 employees working in 19 governmental office buildings in the Netherlands, we measured physical and chemical factors, airborne microorganisms, and endotoxin. Mechanically ventilated buildings were grouped as "healthy" or "sick" based on symptom prevalence (mean symptom prevalence < 15% or > or = 15%). We compared physical, chemical, and microbiological characteristics between mechanically ventilated and naturally ventilated buildings.

RESULTS

Gram-negative rods were found in higher numbers in the "sick" buildings. The concentration of airborne endotoxin was six to seven times higher in the "sick" buildings than in the "healthy" buildings (254 vs 46 ng/m3); it was 35 ng/m3 in naturally ventilated buildings. No differences in physical characteristics of the buildings were found. Volatile organic compounds and carbon dioxide were present at higher concentrations in naturally ventilated buildings.

CONCLUSION

Airborne microbial contamination, in particular with gram-negative rods and perhaps with endotoxin, may have a role in the causation of sick building syndrome.

Influence of long-term ethanol treatment on rat liver biotransformation enzymes

The influence of rats' long-term ethanol consumption on liver enzymes that could be involved in the biotransformation of benzo(a)pyrene [B(a)P] has been studied. Male and female Wistar rats received an increasing amount of ethanol in their drinking water up to 15% (w/v) in three weeks. The ethanol content was kept at a concentration of 15% for another three weeks. One group of rats also received B(a)P in the last week of the ethanol treatment. Livers were isolated, and microsomal and cytosolic fractions were prepared. In every enzyme measurement sex differences were observed. Long-term ethanol consumption induced P450, especially aniline 4-hydroxylase (P4502E1). However, testosterone 6 beta-hydroxylase (P4503A2 and P4502C13) in males and testosterone 12 beta-hydroxylase in females were decreased. The phase 2 enzymes glutathione S-transferase (subunit 1) and epoxide hydrolase were also decreased in their activity. Our results support the hypothesis that the effect of long-term ethanol consumption on B(a)P biotransformation as found in in vivo and in vitro studies, consisting of lowered formation of phenolic and diolic metabolites, is the result of a decrease of constitutive P450 isoenzymes.