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INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 3, No 3, 2012
© Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0
Research article ISSN 0976 – 4402
Received on October 2012 Published on November 2012 1010
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in
Hospital Wards
B.Pritam
1, B.Mukta
2
1. Consultant, Enviornmental Architect, Associate- Chandrashekhar architects, Mumbai
2. Assistant Professor, Department of Physiology, Topiwala National Medical College,
Mumbai
doi: 10.6088/ijes.2012030133009
ABSTRACT
Patient‟s perceptions are gaining popularity to evaluate the quality of healthcare facilities
delivered. A study was conducted to understand the visual comfort condition of hospital ward
patients with reference to the physical aspects of natural, artificial and ambient light. We
undertook an observational study in which 136 consecutive inpatients of both the genders
were evaluated. POE (Post occupancy evaluation) questionnaire method for visual comfort in
3 multi-specialty hospitals was used for assessment. Post occupancy evaluation allows direct
comparison of the physical parameters with the inputs of the occupant‟s perception. The
gathered data was analyzed using SPSS statistical package to determine the co-relation in
patient‟s visual comfort and light levels. The qualitative findings noted a positive
contribution of patient satisfaction and daylight (72%) as well as ambient daylight levels
(77%). Thus, there is preference for natural day lighting as against artificial lighting and
natural lighting reduces lighting energy demand. Also, there is a positive preference to certain
illumination quality and levels in patients for visual comfort. This study hence provides data
for visual comfort which is the main and yet understudied determinant of lighting
requirements in a ward setup and also suggests economical recommendations to modify
architectural design and maximize use of natural light in wards.
Keywords: Light; Visual comfort; Post- occupancy evaluation; Academic hospitals; India.
1. Introduction
Hospitals today have evolved as advanced centers for healthcare- diagnostics and research,
recovery and preventive health facilities. Hospitals have a large ecological foot print. The
wards in hospitals form the largest component of any hospital setup. There are a number of
factors beyond good medical practices and safe environment that contribute to patient healing.
The term „Healing environment‟ (Geimer-Flanders, 2009) implies creating an environment
physically healthy and psychologically appropriate which would indirectly contribute to
patient‟s well-being. Indoor environment of these wards play a critical role in recovery of the
patients, where in light has the most significant role in modeling this indoor environment.
Adequate daylight and outdoor view in interior spaces enables efficient performance of visual
tasks and reduce errors in work environment. It has long been identified that light reaching
brain cells affects the body‟s circadian cycles which are biological events that repeat
themselves at regular intervals (Golombek and Rosenstein 2010). When UV light interacts
with skin, it triggers the formation of vitamin D. It is now proved that vitamin D is required
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
B.Pritam, B.Mukta
International Journal of Environmental Sciences Volume 3 No.3, 2012 1011
not only for bone growth and remodeling but also for immune function, cell growth,
differentiation and apoptosis (Prentice et al. 2008). The role of low levels of vitamin D in
different types of cancer is being widely investigated (Garland et al. 1989; Krishnan et al.
2003; John et al. 1999; Lappe et al. 2007).
Previous studies have also shown a positive association between abundant daylight levels and
physical and psychological well-being after illness or injury. Aldemir (2001) reported
increased frequency of episodes of organic delirium in intensive care unit without windows.
Sunny rooms have been shown to lower the length of stay of patients. Several studies have
shown co-relation between depressive symptoms of seasonal affective disorder (SAD) and
shorter exposure to daylight (Lewy 1987; Terman et al. 1989; Wirz-Justice 2006). A majority
of studies have examined the effectiveness of natural (Benedetti et al. 2001) and artificial
bright light (Beauchemin and Hays 1996; Rosnethal et al.1984) on reducing depression.
An important subjective determinant of lighting levels is visual comfort. It is defined as
satisfaction of visual system and the absence of glare. However, it also depends on several
factors: interaction between all senses, architectural design, mood, aesthetic preferences to
name a few (Dubois et al. 2007). An adequate lighting condition thus control body‟s
circadian rhythm, affects mood and perception and is critical for patient as well as staff well-
being. The POE (Post Occupancy Evaluation) is a sub-process of BPE (Building Performance
Evaluation) and can be defined as act of evaluating a building with a systematic, research
based approach. The early model started in 1960‟s but was detailed and defined by Preiser
((Preiser and Nasar 2008), along with others (Thomson et al. 2003, Carthey 2006 and Cooper
et al. 1991). The study of post occupancy evaluation of Philip Merrill Environmental Centre
(Heerwagen and Zagreus 2005) was a beginning of understanding into how the human factor
impacts sustainable design practice. The results indicated close to 90% of the occupants were
satisfied with day lighting, the overall amount of light, and access to views. The occupant
survey, developed by the Centre for the Built Environment (CBE) at UC Berkeley (Zagreus
et al. 2004) includes a core section with questions on satisfaction with the workplace
environment, and an additional module with questions on psychosocial experience and
organizational satisfaction. The scores clearly indicate the positive response to most criteria‟s,
except the acoustical quality neutrally rated.
This study thereby acknowledged the importance of an evidence-based approach to
architectural design. The study by use of POE (Post Occupancy Evaluation) method aims at
understanding of the actual values as compared to standards. Post Occupancy Evaluation of
lighting in hospital wards allows direct comparison of the physical parameters with the inputs
of the occupant‟s perception.
2. Materials and Method
2.1 Site Description and data collection
This study examines how light affects patient‟s visual comfort in three multispecialty
hospitals in Belgaum, Karnataka, India. The entire data was collected from January 2011 to
May 2011. The sites are identified in one climatic zone as thermal comfort – humidity and
temperature are constant, the visual comfort as prime criteria. The selection of the patients for
interview were based on the variation of ward typologies and further orientation and location
of bed with reference to the source of light. The questionnaire for visual comfort for light was
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1012
based on the assumption that the patient is hospitalized with a non-critical illness, is not an
emergency case, and not an ophthalmic patient. The questionnaire‟s aim was to understand
the patient‟s response to natural, artificial and ambient light at various time of the day. The
questionnaire was drafted and reviewed by two academic professors for accuracy and validity.
A pilot study in 25 patients was conducted to pre-test the content. The patient‟s response was
graded as satisfactory or non-satisfactory.
2.2 Devices and Instruments
The data collected for lux levels by digital lux meter at bed height (600 mm) at minimum
number of locations as per Bureau of Energy Efficiency (BEE) criteria in the ward with “as-
is” condition. The photometer was calibrated and all the recordings were made at different
time of day and night. Further the daylight component is measured by putting all artificial
light in “switch off” mode. The amount of artificial light during the day, along with the type
of fixture and wattage shall be recorded. The artificial lighting during night shall be recorded,
along with the type of fixture and wattage. The artificial light component is assumed as the
differential between the natural light and the total ambient light. The lighting power density
(LPD) was measured as watts per meter square.
2.3 “Ambient lux level” (Average Illuminance) (BEE Code Lighting, 2006)
Determine the minimum no of readings required as per the Table-1 for RI (Room Index).
Room index, RI = L X W
Hm X (L + W)
Where L = Length
W = Width
Hm= Height of the luminaries above the plane of measurement
Table 1: Minimum number of points for illuminance measurements
Figure 1: BEE Diagram for lux level measurement points
Room index Minimum number of measurement points
For + 5% accuracy For + 10% accuracy
RI < 1 8 4
1< RI < 2 18 9
2< RI < 3 32 16
RI > 3 50 25
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1013
Average illuminance, Eav = E1+E2+E3+ .......+En X correction factor
N
E1, E2, E3, - - - - En are the Lux Levels at Points “X” in the room.
Correction Factor as per manufacturer or standard Calibrated instrument Refer BEE Code.
Total available lumens on the measurement plane = Average illuminance X (L X W)
3. Findings for visual comfort
Graph 1: Patients preferring natural light viz a viz artificial light
The Y- axis is the no of patients,
X axis 0- no say=12%, 1- artificial light= 15%, 2- natural light = 72.5%
Graph 2: Patients experiencing Glare
The Y- axis is the no of patients,
X axis 0- NA = 5%, 1- No = 60%, 2- Yes = 35%
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1014
Graph 3: Patients age and satisfaction (Artificial lighting ambient)
The X- axis the age, Y – axis 1- dissatisfied, 2- satisfied
Graph 4: Lighting Power Density and Lux levels
w/sq.m
lux
The Y- axis- LPD, X – axis- L=lux levels
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1015
Table 2: Ambient Lux levels measured at 0800hrs, patient satisfaction
LUX
Patients Total
NOT
SATISFACTORY SATISFACTORY
< 50
Count 2 4 6
% within
ALL8H 33.30% 66.70% 100.00%
51-150
Count 19 38 57
% within
ALL8H 33.30% 66.70% 100.00%
151-300
Count 4 38 42
% within
ALL8H 9.50% 90.50% 100.00%
301-500
Count 2 25 27
% within
ALL8H 7.40% 92.60% 100.00%
> 500
Count 3 1 4
% within
ALL8H 75.00% 25.00% 100.00%
Total
Count 30 106 136
% within
ALL8H 22.10% 77.90% 100.00%
Pearson Chi-Square value= 18.388 P= 0.001 (significant)
Table 3: Ambient Lux levels measured at 1200hrs, patient satisfaction
Lux
Patients Total
NOT
SATISFACTORY SATISFACTORY
> 50
Count 3 3 6
% within
ALL12H 50.00% 50.00% 100.00%
51-150
Count 13 14 27
% within
ALL12H 48.10% 51.90% 100.00%
151-300
Count 3 77 80
% within
ALL12H 3.80% 96.30% 100.00%
301-500
Count 3 20 23
% within
ALL12H 13.00% 87.00% 100.00%
Total
Count 22 114 136
% within
ALL12H 16.20% 83.80% 100.00%
Pearson Chi-Square value= 34.693(a) P= 0.00 (highly significant)
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1016
Table 4: Ambient Lux levels measured at 1600hrs, patient satisfaction
Lux
Patients Total
NOT
SATISFACTORY SATISFACTORY
51-150
Count 10 69 79
% within
ALL16H 12.70% 87.30% 100.00%
151-300
Count 8 16 24
% within
ALL16H 33.30% 66.70% 100.00%
301-500
Count 8 8 16
% within
ALL16H 50.00% 50.00% 100.00%
> 500
Count 7 9 16
% within
ALL16H 43.80% 56.30% 100.00%
Total
Count 33 102 135
% within
ALL16H 24.40% 75.60% 100.00%
Pearson Chi-Square value= 15.855(a) P= 0.001 (significant)
Table 5: Ambient Lux levels measured at 2000hrs, patient satisfaction
Lux
Patients Total
NOT
SATISFACTORY SATISFACTORY
>50
Count 16 65 81
% within
ALL20H 19.80% 80.20% 100.00%
51-150
Count 2 46 48
% within
ALL20H 4.20% 95.80% 100.00%
151-300
Count 5 0 5
% within
ALL20H 100.00% 0.00% 100.00%
Total
Count 23 111 134
% within
ALL20H 17.20% 82.80% 100.00%
Pearson Chi-Square value= 30.215(a) P= 0.00 (highly significant)
There is a significant variation in illumination levels within the same ward. There is a
variation in the day light distribution across the ward largely due to size of ward, orientation,
window type, shading type and different elevation of the wards. Out of the 136 patients one
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1017
respondent was discharged prior to 1600 hrs and another prior to 2000 hrs and hence were
unable to complete the questionnaire.
3.1 Patient satisfaction and daylight/ artificial light
High percentages (72%) of patients prefer daylight (Graph 1). Dissatisfaction of daylight is
mainly due to glare (35% patients experienced glare) (Graph 2). Undesirable glare was found
from artificial lighting in pediatric ward due to fixture mounting at low level and fixture
design.
3.2 Patient satisfaction and ambient light
High number of patients (77%) are satisfied with the ambient daylight levels, expect for some
cases especially during 0800 hrs and 1600hr (Tables 2-5). Though there is an indication of
satisfactory ambient lighting, the in-charge feedback was that there should be better
illumination levels at day and night. Good number of patients (80%) is satisfied with the
ambient artificial lighting, though cases of inadequacy are indicated due to location of fixture,
maintenance, and canopies. Higher percentage of patient satisfaction was found at ambient
day illumination range of 150 to 300 lux as compared to the recommended range of 50 to 150
lux. For night ambient illumination significant number of patient‟s preference was about 50
lux (range 30 to 100 lux) as compared to the recommended range of 30 to 50 lux at bedside
(NBC, 2005).The average patient being aged 40 years and age group ranging from 22 to 75
years, (pediatric ward not considered) there seem to be no clear indication as age related
demand for lighting (Graph 3).
3.3 Lighting Power Density and lux levels
It is observed that the LPD is not largely affected by natural light as the need for power
during natural lighting hours is almost nil. Introduction of proper natural light helped reduce
lighting power requirement during day. The LPD in all the case studies range from minimum
1.46w/sq.m. to maximum 5.62 w/sq.m. for illumination range of 16 lux to 247 lux. The
average at an output of ambient 54 lux at 2.67 w/sq.m. is observed (Graph 4). This is far
below the recommended LPD of 7.5w/sq.m in lux range of 50 to 150 lux for ambient light
(ECBC, 2009).
4. Discussion:
The study explores visual comfort in hospitalized patients. Previous studies have explored the
effect of physical environment in ICU patients and staff (Chaudhary 2009, Shepley et al.
2012, Tsai et al. 2007). However there is a paucity of data with reference to light comfort
levels in hospitalized patients. The study indicated that there is a positive preference to
certain illumination quality and levels in patients for visual comfort. Though there is also a
notable variation to in the indications provided by this sample size, which could imply that
enhanced sample size and parameters could be considered in future for such study. This study
also reinstates the fact that day light is more preferred as compared to artificial light,
indicating its importance in the circadian cycle. This is in accordance with a previous study
by Roche et al. 2000 which illustrated that occupants preferred zones located near windows
for most activities. Also is the established fact that proper consideration of day light in any
indoor environment can stimulate positive response from the occupants; which could be
inferred as that the artificial light must preferably simulate a natural light spectrum cycle.
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
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International Journal of Environmental Sciences Volume 3 No.3, 2012 1018
The above also highlights the importance of proper colour rendition and proper distributions
of light, by implementing design parameters that help attain uniformity in illumination,
brightness and prevent glare. The present study has some significant revelations; indicating
the preference for higher range of illuminations as compared to the recommended. The
concept of proper implementation of optimal ambient light and further providing task light is
upheld.
5. Conclusion
The study indicates through inference the validity of the hypothesis; “there is a positive
preference to certain light quality and illumination levels in patients for visual comfort.” It is
also important for patients to experience the changing character of daylight. Further as India
lacks a significant user response based studies in this field, there is a lot of scope and need to
generate larger database to draw affirmative conditions of patients response and guidelines
for lighting in wards with the Indian context.
Recommendations (Architectural Design)
Day Lighting
Achieve adequate and uniform distribution of daylight through design; orientation,
window size, location & glazing type, light shelves, room index, dual source, etc.
Achieve deeper penetration of natural light through design of window, ventilators,
skylight, light shelves, courtyards, light wells, light tunnels, etc.
Prevent glare by providing shading, secondary buffers on inside or outside windows
(corridors), operable screens, etc.
Artificial lighting
Achieve uniform illumination, brightness and proper colour rendition; layout and
distribution, fixture selection, controls, etc.
Prevent glare by appropriate lighting layout and distribution, fixture selection, etc.
Achieve appropriate ambient lighting: lighting distribution, provide task lights.
Enhance indoor light and environment with well maintained indoor spaces, indoor
finishes with adequate co-efficient of reflection, well maintained windows and
glazing.
6. References
1. Aldemir M, Ozen S, Kara I, Sir A & Baç B., (2001), Predisposing factors for
delirium in the surgical intensive care unit. Critical Care, 5, pp 265-270.
2. Beauchemin K & Hays P., (1996), Sunny hospital rooms expedite recovery from
severe and refractory depressions. Journal of Affective Disorders, 40 (1-2) pp 49-51.
3. Benedetti F, Colombo C, Barbin B, Campori E & Smeraldi E., (2001), Morning
sunlight reduces length of hospitalization in bipolar depression. Journal of Affective
Disorders, 62 (3) pp 221-223.
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
B.Pritam, B.Mukta
International Journal of Environmental Sciences Volume 3 No.3, 2012 1019
4. Bureau of energy efficiency, under ministry of power, Government of India, (2006),
BEE Code Lighting. available at: www.energymanagertraining.com, accessed during
15 June 2012.
5. Carthey J., (2006), Post occupancy evaluation: development of a standardized
methodology for Australian health projects. The International Journal of Construction
Management, pp 57-74.
6. Chaudhary H., (2009), The Effect of Environmental Design on Reducing Nursing
Errors and Increasing Efficiency in Acute Care Settings. Environment and
Behavior,41 pp 755-786.
7. Cooper B A, Ahrentzen S & Hasselkus B R., (1991), Post-occupancy evaluation: an
environment-behaviour technique for assessing the built environment. Canadian
Journal of Occupational Therapy, 58 (4) pp 181-188.
8. Dubois C, Demers C & Potvin A., (2007), The Influence Of Daylighting On
Occupants: Comfort And Diversity Of Luminous Ambiences In Architecture. In
Proceedings of the Solar Conference, 2, pp. 720. American Solar Energy Society;
American Institute of Architects.
9. ECBC, (2009), Energy Conservation and Building Code. available at: a.org/.../energy-
conservation-and-building-code-ecbc-user-guide, accessed during 16 June 2012.
10. Garland C, Garland F, Shaw E, Comstock G, Helsing K & Gorham E., (1989), Serum
25-hydroxyvitamin D and colon cancer: eight-year prospective study. The Lancet, 334
(8673) pp 1176–1178.
11. Geimer-Flanders J., (2009), Creating a healing environment: Rationale and research
overview. Cleveland Clinic Journal of Medicine, 76 (2) pp S64-S69.
12. Golombek D & Rosenstein R., (2010), Physiology of Circadian Entrainment.
Physiological Reviews, 90, pp 1063-1102.
13. Heerwagen J & Zagreus L., (2005), The human factors of sustainable building
design:post occupation evaluation of the Philip Merrill environmental center,
Annapolis, MD. available at: http:// www.wbdg.org/pdfs/human_factors_cbf.pdf,
accessed during 14 may 2012.
14. John E, Schwartz G, Dreon D & Koo J., (1999), Vitamin D and breast cancer risk:
the NHANES I epidemiologic follow-up study, 1971–1975 to 1992. National Health
and Nutrition Examination Survey. Cancer Epidemiology, Biomarkers & Prevention,
8 (5) pp 399–406.
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
B.Pritam, B.Mukta
International Journal of Environmental Sciences Volume 3 No.3, 2012 1020
15. Krishnan A V, Peehl D M & Feldman D., (2003), Inhibition of prostate cancer
growth by vitamin D: Regulation of target gene expression. Journal of Cellular
Biochemistry, 88 (2) pp 363–371.
16. Lappe J, Travers-Gustafson D, Davies K, Recker, R & Heaney R., (2007), Vitamin D
and calcium supplementation reduces cancer risk: results of a randomized trial. The
American Journal of Clinical Nutrition, 85 (6) pp 1586-1591.
17. Lewy A., (1987), Treating chronobiologic sleep and mood disorders with bright light.
Psychiatric Annals, 17 (10) pp 664-669.
18. National Building Code of India, (2005), Bureau of Indian standards, Part 8 Building
Services Section 1, Lighting and Ventilation pp. 770.
19. Preiser W & Nasar J., (2008), Assessing building performance: Its evolution from
post-occupancy evaluation. Archnet-IJAR: International Journal of Architectural
Research, 2 (1) pp 84-89.
20. Prentice A, Goldberg G & Schoenmakers I., (2008), Vitamin D across the lifecycle:
physiology and biomarkers. American Journal of Clinical Nutrition, 88 (2) pp 500S-
506S.
21. Roche L, Dewey E & Littlefair P., (2000), Occupant reactions to daylight in
offices.Lighting Research and Technology, 32(3) pp 119-126.
22. Rosenthal N E, Sack DA, Gillin J C, Lewy A J, Goodwin F K, Davenport Y, Mueller
P S, Newsome D A & Wehr T A., (1984), Seasonal affective disorder. A description
of the syndrome and preliminary findings with light therapy. Archives of General
Psychiatry, 41 (1) pp 72-80.
23. Shepley M, Gerbi R, Watson A, Imgrund S & Zadeh R., (2012), The impact of
daylight and views on ICU patients and staff. Health environment research and design
journal, 5 (2) pp 46-60.
24. Terman M, Terman J, Quitkin F, Mc Grath P, Stewart J & Rafferty B., (1989), Light
therapy for seasonal affective disorder: A review of efficacy.
Neuropsychopharmacology, 2(1) pp 1-22.
25. Thomson H, Petticrew M & Douglas M., (2003), Health impact assessment of
housing improvements: incorporating research evidence. Journal of epidemiology and
community health, 57 pp 11-16.
26. Tsai C, Wang M, Liao W, Lu J, Sun P, Lin B & Breen G., (2007), Hospital outpatient
perceptions of the physical environment of waiting areas: the role of patient
A Post-occupancy Evaluation of Patient’s Perception of Visual Comfort in Hospital Wards
B.Pritam, B.Mukta
International Journal of Environmental Sciences Volume 3 No.3, 2012 1021
characteristics on atmospherics in one academic medical center. BMC health services
research, 7(1) pp 198.
27. Wirz-Justice A., (2006), Biological rhythm disturbances in mood disorders.
International Clinical Psychopharmacology, 21(1) pp S11–S15.
28. Zagreus L, Charlie H & Edward A., (2004), A web-based POE tool for measuring
indoor environmental quality. available at http://escholarship.org/uc/item/56s462z4
accessed during 12 May 2012.