the reference answer GPT ᴼ ᴾ ᴱ ᴺ ᴬ ᴵ < br / > according to the error information you provide, It can be preliminarily determined that the program cannot run because a value(-1.6) of a variable(ages_score1m) is not observed. This may be due to missing data or typing errors.

Here are some possible solutions:

- Check the data for missing values or unreasonable values. You can use the describe command or summarize command of STATA to view basic information about the data, including the maximum value, minimum value, average value, and standard deviation of variables. If you find that a variable has abnormal values, you can try to remove these outliers or use other methods to fill them.
- Check whether the input command is correct. RCS analysis requires setting several parameters, such as cutoff values, reference groups, and so on. If you enter a command incorrectly, the program may not run correctly. Refer to the official STATA documentation or other tutorials to check that the commands are correct.
- If the problem persists, try other methods of analysis, such as linear regression, logistic regression, and so on. These methods can also be used to explore the relationships between variables and may provide more useful information.

Hopefully these solutions will help you solve the problem. If you are still in doubt, please provide more details so that you can better understand the problem.