Trial Outcomes & Findings for Population Based Lighting Study on Older Adults (NCT NCT05676086)

NCT ID: NCT05676086

Last Updated: 2026-05-26

Results Overview

Pittsburgh Sleep Quality Index (PSQI) ranges from 0 (better) to 21 (worse). A score \<= 5 is associated with good sleep quality, while a score \> 5 is associated with poor sleep quality. A higher PSQI score indicates poorer sleep quality, therefore the hypothesis to be tested is that a participant's sleep quality will improve (i.e. PSQI score will decrease) at the end of the light intervention period compared to baseline. Hence, a negative PSQI difference between baseline and follow-up indicates an improvement in sleep quality.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

191 participants

Primary outcome timeframe

from baseline to the end of the light intervention period - 16 weeks

Results posted on

2026-05-26

Participant Flow

Participant milestones

Participant milestones
Measure
Indoor Light Intervention
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Overall Study
STARTED
98
93
Overall Study
COMPLETED
84
85
Overall Study
NOT COMPLETED
14
8

Reasons for withdrawal

Reasons for withdrawal
Measure
Indoor Light Intervention
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Overall Study
Lost to Follow-up
14
8

Baseline Characteristics

2 participants had missing data

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Total
n=191 Participants
Total of all reporting groups
Age, Continuous
73 Years
n=98 Participants
73 Years
n=93 Participants
73 Years
n=191 Participants
Sex: Female, Male
Female
69 Participants
n=96 Participants • 2 participants had missing data
65 Participants
n=93 Participants • 2 participants had missing data
134 Participants
n=189 Participants • 2 participants had missing data
Sex: Female, Male
Male
27 Participants
n=96 Participants • 2 participants had missing data
28 Participants
n=93 Participants • 2 participants had missing data
55 Participants
n=189 Participants • 2 participants had missing data
Race and Ethnicity Not Collected
0 Participants
Race and Ethnicity were not collected from any participant.
Region of Enrollment
Netherlands
9 Participants
n=98 Participants
5 Participants
n=93 Participants
14 Participants
n=191 Participants
Region of Enrollment
Italy
33 Participants
n=98 Participants
33 Participants
n=93 Participants
66 Participants
n=191 Participants
Region of Enrollment
Estonia
56 Participants
n=98 Participants
55 Participants
n=93 Participants
111 Participants
n=191 Participants
Impact of electric light on sleep quality as measured with the Pittsburgh Sleep Quality Index (PSQI)
5 Score on a scale
n=98 Participants
6 Score on a scale
n=93 Participants
5 Score on a scale
n=191 Participants
EuroQol 5D
0.91 Score on a scale
n=98 Participants
0.91 Score on a scale
n=93 Participants
0.91 Score on a scale
n=191 Participants
Dim Light Melatonin Onset (DLMO)
21.67 Clock time (hours)
n=98 Participants
21.44 Clock time (hours)
n=93 Participants
21.61 Clock time (hours)
n=191 Participants
Circadian rest-activity measures - Interdaily stability (IS)
0.50 Normalized index
n=98 Participants
0.52 Normalized index
n=93 Participants
0.50 Normalized index
n=191 Participants
Circadian rest-activity measures - Relative amplitude (RA)
0.64 Normalized index
n=98 Participants
0.63 Normalized index
n=93 Participants
0.64 Normalized index
n=191 Participants
Circadian rest-activity measures - Intradaily variability (IV)
0.52 Normalized index
n=98 Participants
0.55 Normalized index
n=93 Participants
0.53 Normalized index
n=191 Participants

PRIMARY outcome

Timeframe: from baseline to the end of the light intervention period - 16 weeks

Pittsburgh Sleep Quality Index (PSQI) ranges from 0 (better) to 21 (worse). A score \<= 5 is associated with good sleep quality, while a score \> 5 is associated with poor sleep quality. A higher PSQI score indicates poorer sleep quality, therefore the hypothesis to be tested is that a participant's sleep quality will improve (i.e. PSQI score will decrease) at the end of the light intervention period compared to baseline. Hence, a negative PSQI difference between baseline and follow-up indicates an improvement in sleep quality.

Outcome measures

Outcome measures
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home indoor light intervention: Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only no indoor light: Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Change in Pittsburgh Sleep Quality Index (PSQI)
0 Score change
Interval -1.0 to 2.0
0 Score change
Interval -2.0 to 1.0

SECONDARY outcome

Timeframe: from baseline to the end of the light intervention period - 16 weeks

Change in mental and physical health as measured by Euroqol 5D difference between the baseline and the end of the light intervention period. The Euroqol 5D measures the perceived quality of life and ranges from - 0.57 (worst perceived quality of life) to 1 (best health state). A positive difference from baseline to the end of the follow-up period indicates an improvement in the quality of life.

Outcome measures

Outcome measures
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home indoor light intervention: Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only no indoor light: Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Change in Mental and Physical Health (Euroqol 5D)
0.00 Score change
Interval 0.0 to 0.06
0.00 Score change
Interval -0.05 to 0.04

SECONDARY outcome

Timeframe: from baseline to the end of the light intervention period - 16 weeks

Change in Interdaily Stability (IS), as derived from wrist actigraph, between the baseline and the end of the light intervention period. Interdaily Stability (IS) is an index that estimates the stability of the 24-hour rest-activity rhythm across days, quantifying how consistent individual's daily pattern is over time. It ranges from 0 (absence of a stable rhythm) to 1 (perfectly stable rhythm). The hypothesis to be tested is that a participant's IS will increase at the end of the light intervention period compared to baseline; hence, a positive difference between baseline and follow-up indicates an improved rest-activity rhythm.

Outcome measures

Outcome measures
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home indoor light intervention: Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only no indoor light: Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Change in Circadian Rest-activity Measures - Interdaily Stability (IS)
-0.01 Normalized Index
Interval -0.05 to 0.04
-0.01 Normalized Index
Interval -0.05 to 0.03

SECONDARY outcome

Timeframe: from baseline to the end of the light intervention period - 16 weeks

Change in Intradaily Variability (IV), as derived from wrist actigraphy, between the baseline and the end of the light intervention period. Intradaily Variability (IV) is an index that reflects fragmentation of the 24-hour rest-activity rhythm within a day, based on the frequency of transitions between rest and activity. It ranges from 0 to 1, with higher values indicating more fragmented rhythms. The hypothesis to be tested is that a participant's IV will decrease at the end of the light intervention period compared to baseline; hence, a negative difference between baseline and follow-up indicates an improved rest-activity rhythm.

Outcome measures

Outcome measures
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home indoor light intervention: Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only no indoor light: Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Change in Circadian Rest-activity Measures - Intradaily Variability (IV)
-0.01 Normalized Index
Interval -0.05 to 0.03
-0.02 Normalized Index
Interval -0.06 to 0.01

SECONDARY outcome

Timeframe: from baseline to the end of the light intervention period - 16 weeks

Change in Relative amplitude (RA), as derived from wrist actigraphy, between the baseline and the end of the light intervention period. Relative Amplitude (RA) measures the strength of the 24-hour rhythm: (M10-L5)/(M10+L5). M10 is the mean activity during the 10 most active consecutive hours, and L5 during the 5 least active hours. RA ranges from 0 to 1 and reflects the normalized difference between the most active and least active periods of the day: higher values indicate a well-defined rhythm, lower values a weaker or disrupted rhythm. The hypothesis to be tested is that a participant's RA will increase at the end of the light intervention period compared to baseline; hence, a positive difference between baseline and follow-up indicates an improved rest-activity rhythm.

Outcome measures

Outcome measures
Measure
Indoor Light Intervention
n=98 Participants
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home indoor light intervention: Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home with specific instructions to install it in a room where they spend most of their time, in order to supplement the existing indoor lighting. Thus, all people of the intervention arm will be equipped with the LUMIE Halo lamp. Utilizing both warm-white and cool-white LEDs, Lumie Halo delivers 10,000 lux at 20 cm at maximum brightness in "Day" Mode. The touch slider allows the user to adjust the brightness while mixing the color temperature of the light.
Control Group
n=93 Participants
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only no indoor light: Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only. Exposure to the outdoor intervention will be taken into account in the analysis in three ways, (1) by locating the distance between people's home and the modified outdoor light, (2) by a question about the awareness of the change in outdoor light, timing, and duration of exposure and what they think of it, and (3) by recording the amount of light exposure over the 24 hours during two weeks at baseline and after the 1-year light interventions
Change in Circadian Rest-activity Measures - Relative Amplitude (RA)
-0.01 Normalized Index
Interval -0.05 to 0.03
0.01 Normalized Index
Interval -0.03 to 0.03

Adverse Events

Indoor Light Intervention

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Control Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Francesco Nonino, MD

Azienda USL di Bologna - IRCCS Istituto delle Scienze Neurologiche di Bologna

Phone: +390516225295

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place