One firm, two workforces: within-firm differences in care-staff experience between adult day services and dementia group homes in Japan

Background For-profit ownership is repeatedly associated with thinner staffing in long-term care, but comparisons are made within one service, although many providers operate several. How the experience composition of staff differs between service lines of the same firm has not been examined. Methods We used a census of 24,567 adult day services and 14,236 dementia group homes from Japan’s Long-Term Care Service Information Disclosure System. Shares of full-time care staff with at least three and ten years’ occupational experience were modelled by fractional logit with prefecture fixed effects and firm-clustered standard errors. In firms operating both services, firm fixed-effects models compared the two lines with Holm correction, weighting establishments equally and, separately, firms equally, and also excluding the largest chains. Results In day services, for-profit establishments had lower shares of staff with at least three years’ experience (odds ratio 0.718, 95% CI 0.675–0.765) and at least ten years (0.617, 0.572–0.665) than social welfare establishments; the ten-year gap was smaller in group homes. Within 2,346 firms operating both services, the group home’s share with at least ten years exceeded the day service’s by 2.81% points (95% CI 1.46–4.16) weighting establishments equally and 2.61 (1.19–4.04) weighting firms equally; for at least three years, 2.72 and 1.60 (median firm-level difference zero). Among social welfare corporations the difference held under both weightings and after excluding the largest chains. Among for-profit firms the three-year difference depended on the largest chains (0.08 points weighting firms equally) and the ten-year difference, 2.62 (0.17–5.08), was not significant after Holm correction ( p = 0.073). The full-time share was 9.87 points higher and turnover 1.90 points higher in group homes. Conclusions Within the same firm, the share of experienced care staff is modestly higher in the dementia group home than in the adult day service. The finding is descriptive: heavier regulation of group homes is one explanation, but the services also differ in work, users, capacity and working conditions, and staff movement is unobserved. Higher group-home turnover weighs against, without excluding, a retention explanation. Service-by-service evaluation does not compare a firm’s service lines, although public establishment-level data allow it.