## 2 Materials and Methods
### Measures and Materials  
The Mini-Mental State Examination (MMSE) is an instrument used for the screening of cognitive impairment in the elderly and includes 11 questions. The test evaluates the cognitive functions: attention and orientation, memory, registration, calculation, language and praxis. A low score on the MMSE corresponds to low cognitive functioning [41]. The MMSE was only taken at baseline to map the severity of the dementia. The Katz-Index of Independence in Activities of Daily Living (Katz-ADL) was developed to study the results of treatment and prognosis in the elderly and chronically ill [42]. Grades of the index summarise overall performance in six domains: bathing, dressing, toilet visits, transferring, continence and feeding. Each domain has four answer options, from complete independence to complete dependence. The Katz-ADL is a useful survey instrument to study a prognosis and the effects of treatments and serves as an objective guide in clinical practices, teaching devices and to gain more knowledge about the ageing process [42]. The Katz is a one-dimensional instrument that can be used to retrospectively \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Participant One** & **Participant Two** & **Participant Three** \\ \hline Gender & Male & Female & Female \\ Age & 66 & 67 & 84 \\ Diagnosis & Alzheimer’s disease & Vascular dementia & Alzheimer’s disease + \\ Education & Primary technical school & Middle school & Parkinson’s disease \\ Former work & Truck driver & Interpreter & Domestic help \\ Marital & Married, living with his wife & Widow, living with her & Married, living with her husband \\ status/living situation & & & \\  & & & \\ Medication & Assaantin & Mylan & Quetapine \\ Reminyl & Acetylsalicylicaur & Omeprazol & Omeprazol \\  & & & \\ Amount of lux in the & & & \\ living room & 86 lux in the living room; & 110 lux in the living room; & 121 lux in the living room; & 410 lux near the window \\ (”normal lighting”) & 190 lux near the window & & \\ Informal caregiver & Wife & Daughter & Husband \\ Mini-Mental State & & & \\ Examination (MMSE) & 19/30 (moderate) & 19/30 (moderate) & 20/30 (moderate) \\ Scores (impairment) & & & \\  & Dressing (including & & \\ preparations for dressing) & & & \\ Eating (including & & & \\ preparations for eating) & & & \\ Starting activities & & & \\ Perform activities & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Participant characters at baseline. assess ADL by informants, with construct validity and reliability, despite the presence of cognitive decline [43]. The Katz-ADL has a good internal consistency (Cronbach's alphas: 0.84-0.94) for elderly and strong associations with related outcomes: rank correlations 0.64 for long-term limitations in mobility and \(-\)0.60 for physical functioning [44]. The Lawton IADL is an instrument to assess independent living skills [45]. These skills are considered more complex than the basic activities of daily living as measured by the Katz-ADL. This instrument is most useful for identifying how a person is functioning at the present time and for identifying improvement or deterioration over time. This assessment instrument is widely used both in research and clinical practice [46]. The Lawton IADL has eight questions with four to six answer options. The domains are meal preparation, using a phone, shopping, housekeeping, financial management, medication management, laundry and transport. The validity and reliability were described as good (inter-rater reliability: \(r\) = 0.85 and test-retest reliability: \(r\) = 0.93-0.96 [46]. Positive Perception Programme (PPP) is an online survey consisting of two parts and is used to subjectively measure the received light during the day (part one) and daily ADL outcomes, such as dressing, washing, preparing food and medication intake (part two).