This study was designed to provide an objective measure of the quality of sleep and its predictive factors for hospitalized adult patients at our institution. Our results show that these inpatients have significant impairment in all sleep scales, and a quality of sleep that is inferior to non-institutionalized healthy adults and almost as impaired as insomniacs. Although predictors varied across scales, bedtime sedative use was consistently associated (either positively or negatively, depending on the agent) with sleep outcomes. Sixty percent of our patients received a prescription for a bedtime hypnotic. Thus, it would appear that despite widespread sedative drug use in the hospital, patients still experience sleep impairment. Zopiclone was found to be beneficial for sleep disturbance, but detrimental for sleep effectiveness and supplementation relative to other sedative drugs including benzodiazepines.
Previous investigations have revealed that the most common factors affecting sleep in hospitalized patients include the effects of illness, environmental sleep disruption, additional medication, anxiety, and depression [3, 6, 7]. Insomnia in the hospitalized patient leads to increased fatigue, irritability and aggressiveness as well as decreased pain tolerance.  We found that sleep disturbance was explained by the number of chronic diseases, presence of pain, bedtime sedative use and an interaction term between pain and number of chronic diseases. Of interest, we had expected that as the number of chronic diseases increased, the sleep disturbance score would also increase. However, we found the opposite and are unable to explain this observation. This is further complicated by the interaction term that found that chronic diseases with pain are associated with a decrease in sleep disturbance. Potentially, this could be confounded by the use of narcotic agents (i.e. narcotics would be expected to alleviate pain and may induce sleep) within the hospital. Further investigation into these results is warranted. For the sleep supplementation scale, increasing age was associated with less supplementation. This may be because older people generally require less sleep. For sleep effectiveness, length of hospitalization resulted in lower scores. Thus, for patients with prolonged duration of hospital stay, special attention should be paid to their sleep patterns. Pain was associated with a better sleep effectiveness score (opposite to its impact on sleep disturbance). Again, this result could be confounded by the use of narcotic agents in the hospital.
Tranmer et al  recently assessed the sleep experience of medical and surgical patients during their stay in a Canadian teaching hospital using the Verran and Snyder – Halpern sleep scale. When scores for the 54 medical patients in this study were adjusted for visual analogue scale differences, it is apparent that our study patients generally had reported more sleep disturbance, greater sleep effectiveness and similar sleep supplementation needs. This was likely related to differences in the patient populations (e.g. patients in this recent study tended to be younger, predominantly male and from a limited selection of diagnostic groups) as well as differences in the physical environments between the two study settings. Similar to Tranmer et al, we found an association between sleep quality and a number of internal and external factors. In both studies, patients with longer hospital stays tended to report better sleep, likely reflecting an increased familiarity with the new surroundings. Older patients and those with pain had a poorer quality of sleep.
According to our analysis, approximately one-third of patients used a hypnotic prior to admission and continued therapy during hospitalization for the treatment of insomnia. This observation was not surprising considering the prevalence of insomnia (~25%) in the general population . Sixty percent of patients received a prescription for a hypnotic while in hospital and about one-half of these appear to have been hypnotic-naïve patients. This finding is consistent with observations published in a 2002 report by Ramesh and Roberts . These investigators assessed inpatient and discharge prescribing of benzodiazepines used for sleep induction in two Indian medical wards over a 3-month period and found that 57% of those patients prescribed benzodiazepines in hospital were not taking a benzodiazepine at home prior to admission. Approximately one in three inpatients in our study received a benzodiazepine during admission and this finding is also similar to that reported in 2001 by Elliott et al . Accordingly, it appears that hypnotic agents continue to be widely used in our hospitalized medical patient population and benzodiazepines remains the most commonly prescribed hypnotic drug class for this purpose.
There are several limitations associated with this study. Foremost, we screened 295 patients in order to recruit 100 participants. As such, it is possible, by applying our inclusion/exclusion criteria, that we selected people with less serious sleep deficits. This could potentially bias our results and affect the generalizability of our findings. However, we believe that this is a conservative bias in that we still found a significant proportion and degree of sleep deficits in our sample. While most patients were enrolled within a few days of hospitalization, enrollment was delayed for others and this may have influenced their quality of sleep scores. No attempt was made to directly assess this potential relationship. We relied on patient recollection of sedating drug use prior to admission. Hypnotic use prior to hospitalization was confirmed by a PharmaNetR review; however, over-the-counter and herbal hypnotic agents purchased without a prescription are not captured by this database. For the purposes of quality of sleep comparisons with non-hospitalized patients, we relied on quality of sleep scores reported for a younger, predominantly female sample group.  Accordingly, it is not possible to conclude with any certainty that institutionalization alone accounted for a different in sleep quality between these two groups. Finally, this study involved patients in the general medicine and family practice areas of this hospital only; thus, we cannot extrapolate our results to the general hospital population.
The results of this study reveal that quality of sleep is a problem that affects hospitalized adult medical service patients and a relatively high percentage of these patients are being prescribed a hypnotic prior to and during hospitalization.