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A Review of the article "Effectiveness of Electronic Sensor Bed/Chair Alarm by Lippincott Williams & Wilkins"

Falling of patients from beds is an occurrence that is very common in subacute wards especially among patients with cognitive impairments and may lead to serious injuries. There are over 60% of falls in subacute wards and various strategies have been implemented so as to prevent the falls as well as reduce the injuries that are as a result of the falls. Strategies such as bed exit alarms have been implemented to ensure that there is surveillance of patients who leave their beds by the staff. Bed rails have also been used in the past; however, they have been linked to both direct and indirect injury and hence not commonly used. This paper will focus on the background of patients in subacute wards, the various strategies used to curb the problem, sensor bed/ chair alarm, methods used to ascertain feasibility, acceptability and effectiveness of electronic sensor beds and chairs as well as the recommendations.

Bed alarms may be attached on directly on a patient or attached next to the bed. They are designed in such a way that they alert the staff when a patient tries to leave the bed or when a patient has successfully left the bed. There are various types of bed alarms that commonly used in hospitals; floor sensor mats, garment clip devices, bedside infrared-beam detectors and those triggered by pressure change. Pressure alarms are commonly used; however, they are vulnerable to various setbacks such as insufficient pressure due to low weight of a patient may trigger a false alarm when the patient is not leaving or trying to leave the bed. Floor sensor mats are also faced with a huge setback since they are only triggered when a patient applies pressure on the mats. This means that by the time the alarm goes off, the patient is already out of the bed and hence not effective in preventing a fall and the subsequent injury.

Most of the recent studies on bed- exit alarms as an intervention for reducing falls in acute wards have had conflicting findings. In a 12 month study to evaluate the effectiveness of pressure sensors in reducing the risk of falls that involved 362 patients of an acute hip fracture, it found a huge reduction in the chances of falling. The study however did not report the demographic of patients nor the characteristics of fall risk of the intervention phase. Two more recent RCTs were carried out to evaluate the effectiveness of bed exit alarms. One involved 1839 patients in 5 geriatric wards in public hospitals in UK. The primary outcome of the study was the number of bedside falls while the secondary outcome was the number of injurious falls, health related quality of life, fear of falling and daily living activities. The study reported that there were no big differences in the rate of falling between the control arm and the intervention arm as well as the secondary outcome measures. This study however had certain limitations since the criteria of patients receiving the intervention was not reported as well as the length of the intervention period. This means that the study was not sufficient to detect any change in the rate of the falls.

A second study involved 27,672 patients and used a cluster RCT showed that an 18 month intervention led to the increase of use of bed exit alarm sensors in an urban community hospital. Unexpected closures of some units made it difficult to obtain a significant change in the rates of falls. It is believed that the differences may have risen due to targeting patients with acute fractures or those in the high fall risk group. Other factors such as the acceptability of the alarm system as well as the accuracy of the alarm may have had a great impact in the reduction of falls. The recent studies evaluated the acceptability of the systems by the staff. For instance, in the cluster RCT, the system was accepted by staff, however, the study did not report on the qualitative analysis of the perceptions of the system by the staff. The longitudinal study reported that the system was received well by both patients and staff, however it did not report on their satisfaction about the system. The longitudinal study also reported on the accuracy of the alarm but did not report on the method of analysis or assessment. These two studies had high external validity since there was no recognition of significant terms such as the method of sampling or the accuracy of the alarm systems.

The studies showed no significant change in the falls of patients after the use of the bed sensors since the studies were carried out in acute hospitals where the falls are very low. Had the studies been conducted in a subacute setting where the falls are very high, the use of the bed sensors would have reported a significant reduction on the number of falls. Previous studies have not analyzed the effectiveness of bed-exit alarms on reducing falls especially among the cognitive impaired patients. This means that there exists very little information on the acceptability as well as effectiveness of the bed alarms. This gave rise to the need to evaluate the effectiveness of the electronic sensor alarms in reducing the falls as well as the subsequent injuries cognitive impaired patients in a subacute ward and the acceptability of the systems by the staff. The research questions of this study were; is the sensor bed/ chair alarm feasible? Is it acceptable by the staff? How effective the alarm is in reducing falls of cognitive impaired patients in subacute wards? This study was carried out in a subacute ward where other fall interventions had been applied such as sensor mat but had never been exposed to electronic sensor bed or chair alarms.

The methods of the study comprised two parts; part one is the impact of electronic sensor bed or chair alarm on falls and the related injuries and part two is the electronic sensor alarm feasibility and acceptability by the staff. In the first part method, the method of sampling involved patients that had been admitted for over six months in the subacute ward. The patients to be included had also to have cognitive impairment, high fall risk and required frequent toileting. Patients who were unable to walk were excluded. The data collection for this method involved monitoring of the behavior of the participating patients in regard to the sensor alarms. On the part two method, it invited all the permanent subacute ward nurses to provide feedback using a survey that was anonymous. The method of selecting the nurses to participate involved only those nurses that were permanently employed and worked in the subacute ward. The survey comprised of seven items including ease of operation, usefulness, overall satisfaction in regard to the sensor system as well as three open ended questions. The data collection of this method comprised the anonymous feedback of the participating nurses. This study had a higher internal validity since it recognized and reported the criteria of sampling and selection as well as the accuracy and acceptability of the alarm system based on the nurses feedback.

This method was very reliable since it documented and reported all the relevant details of the study such as the research questions, the process of selecting the participants as well as the methods of collecting data. The results for the part one showed that there was no big difference between the rate of falls in the pre intervention period and the post intervention period. According to the IRR comparisons, there were 1.92 times falls during the pre intervention period and 1.27 falls in the post intervention period. Most of the falls, that is over 98 % resulted in no injury or just minor injury. On part two, results on the accuracy showed that 54.2% gave true positives where the alarm was activated as the patient was leaving the bed or the chair. 42.8% were false positives where the alarm was activated but the patient was not found exiting. 3.0% were false negatives where the alarm failed to activate when the patient was exiting. On nurses’ feedback, 91.7% though that system was very helpful on monitoring of patients exiting their beds or chairs while 91.6 were satisfied with the system.

The analysis of the data collected in this study showed that the overall staffs were convinced that the electronic sensor bed and chair alarm system was effective in providing a means to prevent falls or rapid response in case of a fall. Rapid response in cases of falls helped the nurses to treat any injuries swiftly. The nurse also described certain setbacks of the system. The sensor mat was too narrow resulting to false alarms particularly when not placed in the right position. Another problem was that sensor alarm went through the nurse call system and hence making it difficult to differentiate between a call bell and a sensor alarm. Nurses also cited the need for education on how to use the system on new or casual workers.

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In conclusion, this study provided evidence on the effectiveness and acceptability of electronic sensor bed and chair alarm system as an intervention to help prevent falls cognitive impaired patients in the subacute setting. This evidence is very crucial since cognitive impaired patients are at a very high risk of bed and chair falls as well as the subsequent injuries. However, to further enhance the effectiveness of this system, I would recommend continuous education and training of staff on the use of the system particularly the new and the casual staff. I would also recommend a wireless alarm system so as to eradicate the difficulties associated with the cord system. It is also very important to distinguish the sensor alarm system from the call bell so as to make it easier for the staff to respond swiftly.

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