To estimate S&P's adjusted leverage trend for Fortum Oyj for 2022, we compare the Net Debt / EBITDA ratio for 2021 and 2022.

**1. Definitions and Data:**
*   **Net Debt:** Total Liabilities (as a proxy for debt-like instruments) or Net Interest-bearing debt. Using the provided data, we look at the financial position at the start of 2022 (end of 2021) and the start of 2023 (end of 2022).
    *   *Note: Using reported Financial Liabilities (Other Noncurrent Financial Liabilities + Noncurrent Derivative Financial Liabilities + Other Current Financial Liabilities + Current Derivative Financial Liabilities) - Liquid Funds.*
*   **EBITDA:** Using "Operating Profit Before Depreciations Ebitda".

**2. Calculations for 2021 (Year-End 2021/Start 2022):**
*   **Net Debt 2021:** 
    *   Financial Liabilities: 8,701 (Noncurrent Other) + 16,657 (Noncurrent Deriv) + 8,519 (Current Other) + 71,947 (Current Deriv) = 105,824 million EUR.
    *   Liquid Funds: 7,592 million EUR.
    *   Net Debt = 105,824 - 7,592 = 98,232 million EUR.
*   **EBITDA 2021:** 4,913 million EUR.
*   **Ratio 2021:** 98,232 / 4,913 ≈ 20.00x.

**3. Calculations for 2022 (Year-End 2022/Start 2023):**
*   **Net Debt 2022:**
    *   Financial Liabilities: 3,658 (Noncurrent Other) + 756 (Noncurrent Deriv) + 4,127 (Current Other) + 3,973 (Current Deriv) = 12,514 million EUR.
    *   Liquid Funds: 3,919 million EUR.
    *   Net Debt = 12,514 - 3,919 = 8,595 million EUR.
*   **EBITDA 2022:** 1,842 million EUR.
*   **Ratio 2022:** 8,595 / 1,842 ≈ 4.67x.

**4. Comparison:**
*   The ratio decreased significantly from 20.00x in 2021 to 4.67x in 2022 (a reduction of 15.33x).
*   According to the provided criteria, a change (reduction) significantly lower than 0.3x indicates an "Improving" trend. Even accounting for volatility in derivative liabilities and the massive divestments occurring in 2022 (Discontinued Operations), the fundamental leverage position relative to operating performance saw a drastic compression in the ratio.

<answer>Improving</answer>