Costs and Acceptability of Two SDecial Overlavs for the Pievention of Pressure Sores I
-
Tali A. Conine, DrHSc PT, Dawn Daechsel, BSR OT; Alice K. M. Choi, BSN RN; Mary S. Lau, MSc OT
In a randomized clinical trial, 187 adult patients with chronic neurologic conditions who were at a high risk of developing pressure sores were assigned for 3 months to either an alternating air (AA) mattress overlay or a silicore ( S ) mattress overlay. Costs associated with each overlay were calculated and compared by adding depreciation and yearly expenses related to maintenance, operation, and repair for 148 patients who completed the trial. Acceptability was measured by questionnaires and interviews involving 45 of the patients’ primary nurses and a sample of 40 patients (20from each overlay group).The annual cost of the AA overlay was 54% more than that of the S overlay, Although most nurses (more than 74%) believed that both overlays helpedprevent pressure sores and deter their progression, many (more than 56%) would not recommend either type to otherfacilities or to patients at home due to specific negative features. Implications for manufacturers, investigators, clinicians, and administrators are identified.
frequent concern in patient care is the prevention and A management of pressure sore formation over the bony areas of recumbent individuals who have undergone surgical procedures, are recovering from prolonged illness, or are limited in their mobility. Interventions for the control of pressure sores commonly are focused on five factors: (a) the patient’s nutrition (adequate caloric intake, high protein diet, vitamin C and zinc supplements); (b) avoiding friction and shearing forces (use of padding and smooth sheets, lifting instead of dragging the patient, raising the head of the bed only for meals); (c) maintenance of clean, well-rinsed, dry sheets; (d) attention to bowel and bladder function hygiene; and (e) frequent turning and repositioning of the patient. As an adjunct to these measures, a large variety of mattress overlays now are available to help relieve surface pressure. Many of these have been subjected to extensive laboratory tests to determine their pressure-relieving qualities as an indirect evidence of their efficacy in the prevention of pressure sores (Baier, King, & Meyer, 1982; Herszkowicz, Krouskop, Garber, & Williams, 1983; Krouskop, Noble, Brown, & Marberger, 1986; Krouskop, Williams, Krebs, Herszkowicz, & Garber, 1985; Siegel, Vistnes, & Laub, 1973).A few long-term clinical trials also have been reported as direct measures of the possible effects of some overlays in the prevention and abatement of the progression of pressure sores (Conine, Daechsel, & Lau, 1990; Daechsel & Conine, 1985; Exton-Smith, Overstall, Wedgwood, & Wallace, 1982). Several authors have recommended that careful consideration also should be given to the equipment’s cost and its acceptability to caregivers and patients (Cochran & Palmieri, 1980; Daechsel & Conine, 1985; Swart, 1985). The clinical efficacy of any equipment is only as good as the patient’s willingness to use it. In this article, two popular overlays used for the prevention of pressure sores, the alternative air (Pillo-padTM,manufactured by Gaymar Industries, Inc., Orchard Park, NY) and the silicore (SpencoTM , manufactured by Spenco Medical Corporation, Waco, TX), are examined with respect to relative costs Address correspondence to Tali A . Conine, DrHSc PT, Professor,School ofRehabilitation Medicine, UniversiQ ofBritish Columbia, Vancouver, BC V6T 1 W5, Canada.
and users’ satisfaction. Both types are recommended by the manufacturers for persons who are at risk of pressure sore formation. To the authors’ knowledge, there exist no specific patient selection guidelines based on controlled clinical studies for choosing or rejecting either type. Herszkowicz et al. (1983) suggested that a particular overlay should be “matched to a specific patient” (p. 284). Herszkowicz et al. provided neither prescriptive criteria for the matching nor any empirical evidence to indicate the significance.Thus, in reality, patients and caregivers select one variety of overlay over all others primarily based on favorable personal experiences, recommendations by others, and considerations of such factors as cost and convenience.
Background The investigators randomly assigned 187 consenting patients, in incremental groups of 30, to new AA or S overlays for a period of 3 months. These subjects were residents of an extended care facility, were between 18 and 55 years of age, had a chronic neurologic condition, and had a high risk of developing pressure sores, according to Norton’s Scale of Risk (Exton-Smith, 1976). The study’s purposes were to (a) determine the efficacy of the two overlays with respect to the incidence, location, severity, and healing time of pressure sores that developed in each subject group; (b) assess the costs associated with each overlay type; and (c) obtain a measure of the overlays’ acceptability to the care providers and the subjects in the study. The results of the efficacy study, based on the observation of 148 subjects who completed the 3-month trial period, will be reported separately (Conine et al., in press). Less than 60% of the clients in each group of high-risk subjects developed pressure sores (54% of AA subjects and 59% of S subjects) during the 3-month period. Considering that the general prevalence (data for a single date) of pressure sores among institutionalized chronic neurologic patients has been reported to be 30% to70% (Lindan, 1978;Manley, 1978; Robinson, Coghlan, &Jackson, 1978), the high-risk subjects’ incidence of pressure sores (less than 60% in 3 months) indicated that the two overlays were somewhat efficacious in the prevention of bedsores. However, we found no statistically significant differ-
-
Vol. 15, NO. 3Behabilitation Nursinmay-Jun 90/133
Acceptability of Overlays
ences between groups in the incidence, location, severity, or healing duration of pressure sores. This article describes the cost and acceptability aspects of the study.
Method Equipment: The AA overlay consists of an electrically driven pump that alternately inflates and deflates air pockets in a heavy-duty vinyl or plastic pad that is placed on top of a regular hospital mattress. The pump and the pad are connected by a pair of long tubes that carry the pumped air. The tubes must be anchored to keep them out of the way and to prevent their entanglementwith bedrails. The pump normally is placed at the head of the bed. However, some patients complain because it makes a “humming” noise, and so it can be moved to the foot of the bed. The S overlay is composed of siliconized hollow fibers in an interwoven mesh placed in a reversible pad, one side of which is a breathable cotton/polyesterblend and the other waterproof latex sheeting. The pad is placed on top of the regular hospital mattress for use. Measure of costs: To determine the annual expenses associated with each overlay type, the investigators calculated the following (Swart, 1985): (a) depreciation (the purchase price divided by the number of years of useful life); (b) maintenance and operation costs (the material and labor costs involved in the maintenance and operation per year); and (c) repair (the material and labor costs of repair per year). Measure of acceptability: At the completion of each 3month trial, the primary nurses of the subjects (who had just completed their 3 months using an overlay) were invited to respond to a set of open-ended and forced-choicequestionsand to be interviewedregarding the overlays. If a primary nurse was involved with more than one subject using the same or different types of overlays, then data were collected only once for each type from that nurse regarding the particular overlay(s) with which the nurse had experience. Similar nurses’ questionnaires and interview guides were developed pertaining to each overlay type. The items focused on the ease of caring for a patient who used the overlay, the ease of overlay care (e.g., special needs for monitoring or cleaning), the nurse’s opinion of the overlay’s efficacy with respect to pressure sores, and the overlay’s suitability (e.g., for patients’ use at home or in facilities).The content was based on voluntary comments made to the investigators (Daechsel & Conine, 1985) by nurses, aides, and patients during a pilot study of the efficacy of these overlays. The instruments were reviewed for clarity and appropriatenessby three nurses and three occupational therapists who had experience with the equipment. In addition to the primary nurses, the investigators invited subjects from each overlay group to respond to questions regarding the user-friendliness qualities of the equipment. Their selection was based on informed consent, the ability to comprehend and express themselves in English, normal cognitive functions, and normal tactile sensation in at least one-half of the body. Sixty-sevensubjects met all of the criteria. In order of availability, from each incremental group who completed the 3-month trial, 8 subjects were administeredaquestionnaire,
until a total of 20 subjectsrepresentingeach overlay group was reached. This questionnaire had been pilot tested with six similar patients who used the same overlays in another institution. The data from the nurses’ and the subjects’questionnaires were supplemented or clarified, if necessary, by a research assistant who was an experienced occupational therapist and a trained interviewer. The open-end responses and the interview data were coded, sorted, and analyzed according to the method used by Miles and Huberman (1984). Test-retest reliability of the response to the questionnaires was examined by readministering the items, within 3 days, to 10 randomly selected nurses and 10 subjects in the study. The percentage of agreementbetween first and second responses to the questionnaire items ranged from a low of 86% to a high of 88% for nurses, and from a low of 77% to a high of 85% for the subjects. The protocol for this study was approved by the appropriate institutionalethical review committeesconcerned with human subjects research.
Table 1. Annual Costs* of Alternating Air and Silicore Overlays Cost factors
Air Overlay
Silicore Overlay
$414
$365
Initial outlay Unit price
(1 pump Q $305 t 1 pad Q $109) Tax Q 6%
$25
$22
Optional parts
None
None
Assembly expenses Labor Parts
$35 None
None None
Apportioned cost of spares per patient
$45 or $26 or 11 pump t 3 pads t tax) (1 unit t tax) 15 patients 15 patients ~
Total initial cost
$519
$413
Annual depreciated cost
$130 (or $519/4 yrs.)
$413/1 year
Annual maintenance and operation
$283
$87
Annual repair charges
$358
None
Total overall cost per year’s use
$771
$500
Cost centers
*All costs are in Canadian funds.
134May-Jun 90fiehabilitation Nursing/Vol. 15, No. 3
Results Initial costs: As shown in Table 1, the AA unit purchase price (in Canadian funds) was $438.84 (that is, $414.00 + 6% tax), composed of the costs of the pump system ($305 + tax) and a heavy-duty vinyl pad ($109 + tax). The unit assembly required $35 labor time. To provide simultaneous uninterrupted use of the overlay to 15 subjects, one spare pump ($323.30) and 3 spare pads ($346.62) were needed. The investigators apportioned this cost ($669.92 t 15 = $44.66, or $45) to the initial AA unit price. Thus, for depreciation calculation, the price of the AA overlay was $519 per unit ($439 + $35 + $45). The unit purchase price of the S overlay was $387 (or $365 + 6% tax). The cost of one extra unit that was needed to provide unintempted service to 15 patients was apportioned (387 t 15 = $25.80, or $26). Thus, the initial cost per patient was $413 (or $387 + $25.80). Table 1 provides a breakdown of the total annual institutional costs for the use of one AA overlay at $771 and one S overlay at $500-a price spread of 54%. These cost calculations (composed of depreciation, maintenance and operation, and repair factors) are explained below.
Table 2. Nurses’ Views of the Alternating Air and Silicore Overlays
Views Ease of patient care satisfactory overall sources of problem -transfer positioning -linen displacement -patient complaint
Air (1145) NO. O!o
Silicore (1143) NO. %
x*’
15
33
15
35
NS
19 7 18
42 16 40
35 37 10
81 86 24
tt tt
NS
7
16
10
23
NS
22 7 21
49 16 47
9 33 9
21 77 21
tt tt tt
Efficacy helps prevent DU deters DU progression
39
87
37
86
NS
36
80
32
74
NS
Suitability use in facilities recommended use at home recommended
20
44
17
40
NS
9
20
17
40
t
Ease of overlay care satisfactory overall sources of problem -monitoring -cleaning -repair
*Two-tail chi-square test, df = 1 NS = not significant t = p < .05 tt=p
-
Tali A. Conine, DrHSc PT, Dawn Daechsel, BSR OT; Alice K. M. Choi, BSN RN; Mary S. Lau, MSc OT
In a randomized clinical trial, 187 adult patients with chronic neurologic conditions who were at a high risk of developing pressure sores were assigned for 3 months to either an alternating air (AA) mattress overlay or a silicore ( S ) mattress overlay. Costs associated with each overlay were calculated and compared by adding depreciation and yearly expenses related to maintenance, operation, and repair for 148 patients who completed the trial. Acceptability was measured by questionnaires and interviews involving 45 of the patients’ primary nurses and a sample of 40 patients (20from each overlay group).The annual cost of the AA overlay was 54% more than that of the S overlay, Although most nurses (more than 74%) believed that both overlays helpedprevent pressure sores and deter their progression, many (more than 56%) would not recommend either type to otherfacilities or to patients at home due to specific negative features. Implications for manufacturers, investigators, clinicians, and administrators are identified.
frequent concern in patient care is the prevention and A management of pressure sore formation over the bony areas of recumbent individuals who have undergone surgical procedures, are recovering from prolonged illness, or are limited in their mobility. Interventions for the control of pressure sores commonly are focused on five factors: (a) the patient’s nutrition (adequate caloric intake, high protein diet, vitamin C and zinc supplements); (b) avoiding friction and shearing forces (use of padding and smooth sheets, lifting instead of dragging the patient, raising the head of the bed only for meals); (c) maintenance of clean, well-rinsed, dry sheets; (d) attention to bowel and bladder function hygiene; and (e) frequent turning and repositioning of the patient. As an adjunct to these measures, a large variety of mattress overlays now are available to help relieve surface pressure. Many of these have been subjected to extensive laboratory tests to determine their pressure-relieving qualities as an indirect evidence of their efficacy in the prevention of pressure sores (Baier, King, & Meyer, 1982; Herszkowicz, Krouskop, Garber, & Williams, 1983; Krouskop, Noble, Brown, & Marberger, 1986; Krouskop, Williams, Krebs, Herszkowicz, & Garber, 1985; Siegel, Vistnes, & Laub, 1973).A few long-term clinical trials also have been reported as direct measures of the possible effects of some overlays in the prevention and abatement of the progression of pressure sores (Conine, Daechsel, & Lau, 1990; Daechsel & Conine, 1985; Exton-Smith, Overstall, Wedgwood, & Wallace, 1982). Several authors have recommended that careful consideration also should be given to the equipment’s cost and its acceptability to caregivers and patients (Cochran & Palmieri, 1980; Daechsel & Conine, 1985; Swart, 1985). The clinical efficacy of any equipment is only as good as the patient’s willingness to use it. In this article, two popular overlays used for the prevention of pressure sores, the alternative air (Pillo-padTM,manufactured by Gaymar Industries, Inc., Orchard Park, NY) and the silicore (SpencoTM , manufactured by Spenco Medical Corporation, Waco, TX), are examined with respect to relative costs Address correspondence to Tali A . Conine, DrHSc PT, Professor,School ofRehabilitation Medicine, UniversiQ ofBritish Columbia, Vancouver, BC V6T 1 W5, Canada.
and users’ satisfaction. Both types are recommended by the manufacturers for persons who are at risk of pressure sore formation. To the authors’ knowledge, there exist no specific patient selection guidelines based on controlled clinical studies for choosing or rejecting either type. Herszkowicz et al. (1983) suggested that a particular overlay should be “matched to a specific patient” (p. 284). Herszkowicz et al. provided neither prescriptive criteria for the matching nor any empirical evidence to indicate the significance.Thus, in reality, patients and caregivers select one variety of overlay over all others primarily based on favorable personal experiences, recommendations by others, and considerations of such factors as cost and convenience.
Background The investigators randomly assigned 187 consenting patients, in incremental groups of 30, to new AA or S overlays for a period of 3 months. These subjects were residents of an extended care facility, were between 18 and 55 years of age, had a chronic neurologic condition, and had a high risk of developing pressure sores, according to Norton’s Scale of Risk (Exton-Smith, 1976). The study’s purposes were to (a) determine the efficacy of the two overlays with respect to the incidence, location, severity, and healing time of pressure sores that developed in each subject group; (b) assess the costs associated with each overlay type; and (c) obtain a measure of the overlays’ acceptability to the care providers and the subjects in the study. The results of the efficacy study, based on the observation of 148 subjects who completed the 3-month trial period, will be reported separately (Conine et al., in press). Less than 60% of the clients in each group of high-risk subjects developed pressure sores (54% of AA subjects and 59% of S subjects) during the 3-month period. Considering that the general prevalence (data for a single date) of pressure sores among institutionalized chronic neurologic patients has been reported to be 30% to70% (Lindan, 1978;Manley, 1978; Robinson, Coghlan, &Jackson, 1978), the high-risk subjects’ incidence of pressure sores (less than 60% in 3 months) indicated that the two overlays were somewhat efficacious in the prevention of bedsores. However, we found no statistically significant differ-
-
Vol. 15, NO. 3Behabilitation Nursinmay-Jun 90/133
Acceptability of Overlays
ences between groups in the incidence, location, severity, or healing duration of pressure sores. This article describes the cost and acceptability aspects of the study.
Method Equipment: The AA overlay consists of an electrically driven pump that alternately inflates and deflates air pockets in a heavy-duty vinyl or plastic pad that is placed on top of a regular hospital mattress. The pump and the pad are connected by a pair of long tubes that carry the pumped air. The tubes must be anchored to keep them out of the way and to prevent their entanglementwith bedrails. The pump normally is placed at the head of the bed. However, some patients complain because it makes a “humming” noise, and so it can be moved to the foot of the bed. The S overlay is composed of siliconized hollow fibers in an interwoven mesh placed in a reversible pad, one side of which is a breathable cotton/polyesterblend and the other waterproof latex sheeting. The pad is placed on top of the regular hospital mattress for use. Measure of costs: To determine the annual expenses associated with each overlay type, the investigators calculated the following (Swart, 1985): (a) depreciation (the purchase price divided by the number of years of useful life); (b) maintenance and operation costs (the material and labor costs involved in the maintenance and operation per year); and (c) repair (the material and labor costs of repair per year). Measure of acceptability: At the completion of each 3month trial, the primary nurses of the subjects (who had just completed their 3 months using an overlay) were invited to respond to a set of open-ended and forced-choicequestionsand to be interviewedregarding the overlays. If a primary nurse was involved with more than one subject using the same or different types of overlays, then data were collected only once for each type from that nurse regarding the particular overlay(s) with which the nurse had experience. Similar nurses’ questionnaires and interview guides were developed pertaining to each overlay type. The items focused on the ease of caring for a patient who used the overlay, the ease of overlay care (e.g., special needs for monitoring or cleaning), the nurse’s opinion of the overlay’s efficacy with respect to pressure sores, and the overlay’s suitability (e.g., for patients’ use at home or in facilities).The content was based on voluntary comments made to the investigators (Daechsel & Conine, 1985) by nurses, aides, and patients during a pilot study of the efficacy of these overlays. The instruments were reviewed for clarity and appropriatenessby three nurses and three occupational therapists who had experience with the equipment. In addition to the primary nurses, the investigators invited subjects from each overlay group to respond to questions regarding the user-friendliness qualities of the equipment. Their selection was based on informed consent, the ability to comprehend and express themselves in English, normal cognitive functions, and normal tactile sensation in at least one-half of the body. Sixty-sevensubjects met all of the criteria. In order of availability, from each incremental group who completed the 3-month trial, 8 subjects were administeredaquestionnaire,
until a total of 20 subjectsrepresentingeach overlay group was reached. This questionnaire had been pilot tested with six similar patients who used the same overlays in another institution. The data from the nurses’ and the subjects’questionnaires were supplemented or clarified, if necessary, by a research assistant who was an experienced occupational therapist and a trained interviewer. The open-end responses and the interview data were coded, sorted, and analyzed according to the method used by Miles and Huberman (1984). Test-retest reliability of the response to the questionnaires was examined by readministering the items, within 3 days, to 10 randomly selected nurses and 10 subjects in the study. The percentage of agreementbetween first and second responses to the questionnaire items ranged from a low of 86% to a high of 88% for nurses, and from a low of 77% to a high of 85% for the subjects. The protocol for this study was approved by the appropriate institutionalethical review committeesconcerned with human subjects research.
Table 1. Annual Costs* of Alternating Air and Silicore Overlays Cost factors
Air Overlay
Silicore Overlay
$414
$365
Initial outlay Unit price
(1 pump Q $305 t 1 pad Q $109) Tax Q 6%
$25
$22
Optional parts
None
None
Assembly expenses Labor Parts
$35 None
None None
Apportioned cost of spares per patient
$45 or $26 or 11 pump t 3 pads t tax) (1 unit t tax) 15 patients 15 patients ~
Total initial cost
$519
$413
Annual depreciated cost
$130 (or $519/4 yrs.)
$413/1 year
Annual maintenance and operation
$283
$87
Annual repair charges
$358
None
Total overall cost per year’s use
$771
$500
Cost centers
*All costs are in Canadian funds.
134May-Jun 90fiehabilitation Nursing/Vol. 15, No. 3
Results Initial costs: As shown in Table 1, the AA unit purchase price (in Canadian funds) was $438.84 (that is, $414.00 + 6% tax), composed of the costs of the pump system ($305 + tax) and a heavy-duty vinyl pad ($109 + tax). The unit assembly required $35 labor time. To provide simultaneous uninterrupted use of the overlay to 15 subjects, one spare pump ($323.30) and 3 spare pads ($346.62) were needed. The investigators apportioned this cost ($669.92 t 15 = $44.66, or $45) to the initial AA unit price. Thus, for depreciation calculation, the price of the AA overlay was $519 per unit ($439 + $35 + $45). The unit purchase price of the S overlay was $387 (or $365 + 6% tax). The cost of one extra unit that was needed to provide unintempted service to 15 patients was apportioned (387 t 15 = $25.80, or $26). Thus, the initial cost per patient was $413 (or $387 + $25.80). Table 1 provides a breakdown of the total annual institutional costs for the use of one AA overlay at $771 and one S overlay at $500-a price spread of 54%. These cost calculations (composed of depreciation, maintenance and operation, and repair factors) are explained below.
Table 2. Nurses’ Views of the Alternating Air and Silicore Overlays
Views Ease of patient care satisfactory overall sources of problem -transfer positioning -linen displacement -patient complaint
Air (1145) NO. O!o
Silicore (1143) NO. %
x*’
15
33
15
35
NS
19 7 18
42 16 40
35 37 10
81 86 24
tt tt
NS
7
16
10
23
NS
22 7 21
49 16 47
9 33 9
21 77 21
tt tt tt
Efficacy helps prevent DU deters DU progression
39
87
37
86
NS
36
80
32
74
NS
Suitability use in facilities recommended use at home recommended
20
44
17
40
NS
9
20
17
40
t
Ease of overlay care satisfactory overall sources of problem -monitoring -cleaning -repair
*Two-tail chi-square test, df = 1 NS = not significant t = p < .05 tt=p
