. 2018 Nov 12;13(11):e0206508. doi: 10.1371/journal.pone.0206508

Table 1. Formulae to estimate each component of the cost.

Health Care cost	TC_hc = HC_in + HC_out $H C_{i n (o u t)} = \sum_{j = 1}^{10} N_{d e m - i n (o u t) - j} \times M C_{d e m - i n (o u t) - j} \times 12$
Long-Term Care (LTC) cost¹^,²	$T C_{l t c} = \sum_{s = 1}^{2} \sum_{m = 1}^{12} \sum_{i = 1}^{7} N_{s - m - i} \times R_{d e m - s - m - i} \times C_{l t c - s - m - i} \times R R_{d e m - s}$
Informal care cost*¹	$T C_{i c c} = \sum_{i = 1}^{7} N_{l t c - i} \times R_{d e m - o u t - i} \times (T_{i c - a d l - i} \times U C_{a d l} + \times T_{i c - i a d l - i} \times U C_{i a d l}) \times 52$

Abbreviation

TChc = total healthcare cost, HCin = inpatient cost, HCout = outpatient cost, Ndem-in(out)-j = the monthly number of the inpatients (outpatients) with dementia at sex and age band of j

MCdem-in(out)-j = monthly mean cost of inpatient (outpatient) at sex and age band of j

TCltc = total LTC cost of dementia, Ns-m-i = the number of the people with care needed level i at month of m receiving LTC services of s

Rdem-s-m-i = the rate of the people with dementia among all users with care needed level i at month of m receiving LTC services of s

Cltc-s-m-i = the average cost of LTC service of s with care needed level i of those without dementia at month of m

RRdem-s = the relative ratio of the average cost of LTC service of s for those with dementia against that of those without dementia

TCicc = total informal care cost, Nltc-i = the number of people with care needed level i using home care services

Rdem-out-i = rate of the people with dementia among all users of home care services with care needed level i

Tic-adl-i = informal care time for ADL of the people with dementia with care needed level i using home care services (hours/ week)

UCadl = unit cost of informal care for ADL (JPY/hour)

Tic-iadl-i = informal care time for IADL of the people with dementia with care needed level i using home care services (hours/ week)

UCiadl = unit cost of informal care for IADL (JPY/hour)

*1 Care needed level ranging from 1 to 7 represents from support needed level 1 to nursing care level 5

*2 Home care services in LTC schema include three different services (i.e. home-based service, home-based support, and small-scale local service)