Differential diagnosis of MCI with Lewy bodies and MCI due to Alzheimer's disease by visual assessment of occipital hypoperfusion on SPECT images

PURPOSE

Predicting progression of mild cognitive impairment (MCI) to Alzheimer's disease (AD) or dementia with Lewy bodies (DLB) is important. We evaluated morphological and functional differences between MCI with Lewy bodies (MCI-LB) and MCI due to AD (MCI-AD), and a method for differentiating between these conditions using brain MRI and brain perfusion SPECT.

METHODS

A continuous series of 101 subjects, who had visited our memory clinic and met the definition of MCI, were enrolled retrospectively. They were consisted of 60 MCI-LB and 41 MCI-AD subjects. Relative cerebral blood flow (rCBF) on SPECT images and relative brain atrophy on MRI images were evaluated. We performed voxel-based analysis and visually inspected brain perfusion SPECT images for regional brain atrophy, occipital hypoperfusion and the cingulate island sign (CIS), for differential diagnosis of MCI-LB and MCI-AD.

RESULTS

MRI showed no significant differences in regional atrophy between the MCI-LB and MCI-AD groups. In MCI-LB subjects, occipital rCBF was significantly decreased compared with MCI-AD subjects (p < 0.01, family wise error [FWE]-corrected). Visual inspection of occipital hypoperfusion had sensitivity, specificity, and accuracy values of 100%, 73.2% and 89.1%, respectively, for differentiating MCI-LB and MCI-AD. Occipital hypoperfusion was offered higher diagnostic utility than the CIS.

CONCLUSIONS

The occipital lobe was the region with significantly decreased rCBF in MCI-LB compared with MCI-AD subjects. Occipital hypoperfusion on brain perfusion SPECT may be a more useful imaging biomarker than the CIS for visually differentiating MCI-LB and MCI-AD.

O-080 Impact of age-limit policy change for assisted reproductive technology (ART) subsidy in Japan

Study question

What was the impact on treatment age in Japan after a subsidy policy change that set age limits for assisted reproductive technology (ART) treatment?

Summary answer

The national policy introducing age limits in the subsidy may have promoted ART treatment among younger women.

What is known already

Japan has provided partial subsidies for ART treatment since 2004. To promote treatment at a younger age, the government introduced a subsidy policy in 2016 that set age limits: up to six treatment cycles for women younger than 40 years of age; and up to three cycles for women between 40 and 42 years old. However, two out of 47 prefectures continued to provide subsidies to women aged 43 and older.

Study design, size, duration

We conducted a time series analysis of the utilisation of ART before and after the introduction of age limits, using data from the Japanese national ART registry from 2012 to 2016.

Participants/materials, setting, methods

We described the number of fresh and frozen treatment cycles, comparing the number between 45 prefectures that followed the national policy change (hereafter, prefectures with age limits) and two prefectures that did not (hereafter, prefectures without age limits). Ordinary least squares regression models were used to assess the impact of the policy change by prefecture on the number of ART cycles by women of different ages.

Main results and the role of chance

The overall number of fresh and frozen ART cycles continuously increased in all age groups from 2012 to 2016. Meanwhile, the number of fresh ART cycles among women aged ≤ 36 and 37-39 years in 2016 increased from the previous year by + 4.0% and +1.8% in prefectures with age limits, whereas it decreased in prefectures without age limits: -3.1% and -2.3%, respectively. The number of fresh ART cycles among women aged 40-42 and 43-45 years in prefectures with age limits in 2016 changed by + 1.5% and -0.1%, respectively, whereas it increased considerably in prefectures without age limits by + 9.6% and +65.4%, respectively. Similar changes were shown for the frozen cycles. After controlling for underlying time trends and prefectural characteristics, the policy change significantly increased the number of fresh and frozen ART treatment cycles among women aged ≤ 36 years and decreased the treatment cycles of women aged 40-42 years.

Limitations, reasons for caution

We evaluated the change observed in the year of the policy change and could not assess longer-term trends. Additionally, unobserved factors might have contributed to the change in treatment numbers.

Wider implications of the findings

The introduction of a policy to set an age limit for the partial ART subsidy resulted in a significant increase in treatment even among age groups younger than the boundary groups. The policy change might have conveyed educational messages regarding the benefits of early treatment.

Trial registration number

not applicable

P–721 Probability of receiving assisted reproductive technology treatment through out-of-pocket payment and household income: A discrete choice experiment in Japan

Study question

What is the probability that patients will receive assisted reproductive technology (ART) treatment based on their out-of-pocket payment and income class?

Summary answer

Higher-income patients opted for ART even at a higher cost, whereas an out-of-pocket payment was the most influential determinant in all income groups.

What is known already

Economic disparities affect access to ART treatment in many countries. At the time of this survey, Japan provided partial reimbursement for ART treatment exclusively for those in low- or middle-income classes due to limited governmental budgets. However, the optimal financial support by income class is unknown.

Study design, size, duration

We conducted a discrete choice experiment (DCE) in Japan in January 2020 including 824 women with fertility problems who were recruited via an online social research panel.

Participants/materials, setting, methods

Participants included women aged 25–44 years undergoing fertility diagnosis or treatment. They completed a DCE questionnaire including 16 hypothetical scenarios, created by orthogonal design, to measure six relevant ART attributes (pregnancy rate, risk of adverse effects, number of visits to outpatient clinics, consultation hours, kindness of staff, and out-of-pocket expense) and their relation to treatment choice. We used mixed-effect logistic regression models to estimate the probability of receiving ART treatment for each attribute.

Main results and the role of chance

Of the 1,247 eligible women recruited, 824 completed the survey (66% participation rate). All six attributes significantly influenced treatment preference, with participants valuing out-of-pocket payment the most, followed by pregnancy rates and kindness of staff. The odds ratios of each attribute to receiving ART treatment were 0.58 (95% confidence interval [CI]: 0.57 − 0.59) for out-of-pocket payments per additional 100,000 Japanese yen (JPY; i.e., 800 euros), 1.47 (95% CI: 1.43 − 1.53) for pregnancy rates per additional 5%, and 4.16 (95% CI: 3.73 − 4.64) for kindness of staff, after adjusting for clinical and socioeconomic factors. Significant interactions occurred between high household income (≥8 million JPY) and high out-of-pocket payment (≥500,000 JPY). However, the mean predicted probability of the highest-income patients (i.e., ≥10 million JPY) to receive ART treatment at the average cost without public funding (i.e., 400,000 JPY) was 47% (interquartile range: 18%−76%), whereas that of middle-income patients (i.e., 6–8 million JPY) to receive ART at the average subsidized cost (i.e., 100,000 JPY) was 60% (interquartile range: 33%–88%).

Limitations, reasons for caution

Other attributes not included in our DCE scenarios might be relevant in real-life settings. Choices made in a DCE would not wholly match the actual treatment choices.

Wider implications of the findings: The present DCE suggested that out-of-pocket payment was the primary determinant in patients’ ART decisions. High-income patients were more likely to receive ART treatment even at a high cost, but their ineligibility for government financial support due to their high income might discourage them from receiving treatment.

Trial registration number

NA