An interventional study of indoor light intervention and no indoor light in Lightning Strategies on Health, Circadian Rhythms Photoentrainment and Photoentrainment and Sleep, sponsored by Azienda Usl di Bologna. Completed at 1 site in Italy. Open to participants aged 65 Years and older. Per ClinicalTrials.gov, last updated 2026-05-26.
Sponsored by Azienda Usl di Bologna · Not applicable, Interventional, and Health services research
The ENLIGHTENme project aims at collecting evidence about the impact of outdoor and indoor lighting on human health and wellbeing through the development and testing of innovative solutions and policies that will also counteract health inequalities in European cities. In particular, through an open-online Urban Lighting and Health Atlas, ENLIGHTENme will collect and systematize existing data and good practices on urban lighting and will perform an accurate analysis on the correlations among health, wellbeing, lighting and socio-economic factors in three pilot cities: Bologna (Italy), Amsterdam (The Netherlands), and Tartu (Estonia).
The ENLIGHTENme project aims at collecting evidence about the impact of outdoor and indoor lighting on human health and wellbeing through the development and testing of innovative solutions and policies that will also counteract health inequalities in European cities. In particular, through an open-online Urban Lighting and Health Atlas, ENLIGHTENme will collect and systematize existing data and good practices on urban lighting and will perform an accurate analysis on the correlations among health, wellbeing, lighting and socio-economic factors in three pilot cities: Bologna (Italy), Amsterdam (The Netherlands), and Tartu (Estonia).
In this context, the ENLIGHTENme project will also include an interventional, multicenter, prospective, randomized, controlled, unblinded trial involving one target district, selected based on its artificial light characteristics, in the urban areas of each of one of the three pilot cities. Within each target district, a random sample of individuals aged 65 years or older (intervention group) will be exposed to modifications in domestic indoor lighting and compared with a control group, living in the same target district, unexposed to domestic electric light modifications. At the same time, in a specific area of the target district, outdoor lighting will be modified by the local municipal authority. The hypothesis to be tested in this study is that light interventions may improve individual physical and mental health by affecting circadian entrainment, sleep pattern, and mood. Thus, the study is aimed at providing evidence whether the planned change in electric light exposure at both urban public outdoor and domestic indoor lighting levels may impact on physical and mental health by improving photo-entrainment of circadian rhythms to the light-dark cycle
Azienda Usl di Bologna is the lead sponsor of 40 studies on the registry; 12 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Persons allocated to the indoor light intervention arm will be given a lamp to be placed at home
Behavioral: indoor light intervention
Persons allocated to the control group will receive no indoor light supplementation and will undergo assessment procedures only
Behavioral: no indoor light
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.
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)
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.
Time frame: from baseline to the end of the light intervention period - 16 weeks
Change in Mental and Physical Health (Euroqol 5D)
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.
Time frame: from baseline to the end of the light intervention period - 16 weeks
Change in Circadian Rest-activity Measures - Interdaily Stability (IS)
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.
Time frame: from baseline to the end of the light intervention period - 16 weeks
Change in Circadian Rest-activity Measures - Intradaily Variability (IV)
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.
Time frame: from baseline to the end of the light intervention period - 16 weeks
Change in Circadian Rest-activity Measures - Relative Amplitude (RA)
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.
Time frame: from baseline to the end of the light intervention period - 16 weeks
| Milestone | Indoor Light Intervention | Control Group |
|---|---|---|
| Started | 98 | 93 |
| Completed | 84 | 85 |
| Not completed | 14 | 8 |
| Withdrew: Lost to follow-up | 14 | 8 |
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.
| Score change | Indoor Light Intervention | Control Group |
|---|---|---|
| Change in Pittsburgh Sleep Quality Index (PSQI) | 0 (-1 to 2) | 0 (-2 to 1) |
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.
| Score change | Indoor Light Intervention | Control Group |
|---|---|---|
| Change in Mental and Physical Health (Euroqol 5D) | 0.00 (0.00 to 0.06) | 0.00 (-0.05 to 0.04) |
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.
| Normalized Index | Indoor Light Intervention | Control Group |
|---|---|---|
| Change in Circadian Rest-activity Measures - Interdaily Stability (IS) | -0.01 (-0.05 to 0.04) | -0.01 (-0.05 to 0.03) |
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.
| Normalized Index | Indoor Light Intervention | Control Group |
|---|---|---|
| Change in Circadian Rest-activity Measures - Intradaily Variability (IV) | -0.01 (-0.05 to 0.03) | -0.02 (-0.06 to 0.01) |
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.
| Normalized Index | Indoor Light Intervention | Control Group |
|---|---|---|
| Change in Circadian Rest-activity Measures - Relative Amplitude (RA) | -0.01 (-0.05 to 0.03) | 0.01 (-0.03 to 0.03) |
Collected over 16 weeks. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Indoor Light Intervention | 0/98 (0%) | 0/98 (0%) | 0/98 (0%) |
| Control Group | 0/93 (0%) | 0/93 (0%) | 0/93 (0%) |
| Age, Continuous(Years) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Median | 73 (68 to 77) | 73 (68 to 77) | 73 (68 to 77) |
| Sex: Female, Male(Participants) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Female | 69 | 65 | 134 |
| Male | 27 | 28 | 55 |
| Race and Ethnicity Not Collected(Participants) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Count of participants | — | — | 0 |
| Region of Enrollment(Participants) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Netherlands | 9 | 5 | 14 |
| Italy | 33 | 33 | 66 |
| Estonia | 56 | 55 | 111 |
| Impact of electric light on sleep quality as measured with the Pittsburgh Sleep Quality Index (PSQI)(Score on a scale) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Median | 5 (3 to 7) | 6 (4 to 8) | 5 (3 to 7.25) |
| EuroQol 5D(Score on a scale) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Median | 0.91 (0.82 to 0.95) | 0.91 (0.82 to 0.96) | 0.91 (0.82 to 0.95) |
| Dim Light Melatonin Onset (DLMO)(Clock time (hours)) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Median | 21.67 (20.48 to 22.79) | 21.44 (20.12 to 22.71) | 21.61 (20.42 to 22.81) |
| Circadian rest-activity measures - Interdaily stability (IS)(Normalized index) | Indoor Light Intervention | Control Group | Total |
|---|---|---|---|
| Median | 0.50 (0.42 to 0.56) | 0.52 (0.43 to 0.58) | 0.50 (0.42 to 0.57) |
2 further baseline measures are reported on the registry.
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Azienda Usl di Bologna