
    In a hospital's patient monitoring system, given a list of patient assessments where each assessment contains a patient ID and their readmission risk score, identify the patient ID with the most critical risk score (lowest numerical value). The risk scores are calculated based on various health indicators, where lower scores indicate higher risk requiring immediate medical attention.
    

    
from operator import itemgetter

def index_minimum(test_list):
    """
    In a hospital's patient monitoring system, given a list of patient assessments where each assessment contains a patient ID and their readmission risk score, identify the patient ID with the most critical risk score (lowest numerical value). The risk scores are calculated based on various health indicators, where lower scores indicate higher risk requiring immediate medical attention.
    

    """
from operator import itemgetter

def index_minimum(test_list):
    """
    In a hospital's patient monitoring system, given a list of patient assessments where each assessment contains a patient ID and their readmission risk score, identify the patient ID with the most critical risk score (lowest numerical value). The risk scores are calculated based on various health indicators, where lower scores indicate higher risk requiring immediate medical attention.
    

    """
    res = min(test_list, key=itemgetter(1))[0]
    return res