United Kingdom National Health Service Patient Identifiers

Introduction

The function clean_gb_nhs() cleans a column containing United Kingdom National Health Service patient identifier (NHS) strings, and standardizes them in a given format. The function validate_gb_nhs() validates either a single NHS strings, a column of NHS strings or a DataFrame of NHS strings, returning True if the value is valid, and False otherwise.

NHS strings can be converted to the following formats via the output_format parameter:

• compact: only number strings without any seperators or whitespace, like “9434765870”

• standard: NHS strings with proper whitespace in the proper places, like “943 476 5870”

Invalid parsing is handled with the errors parameter:

• coerce (default): invalid parsing will be set to NaN

• ignore: invalid parsing will return the input

• raise: invalid parsing will raise an exception

The following sections demonstrate the functionality of clean_gb_nhs() and validate_gb_nhs().

An example dataset containing NHS strings

import pandas as pd
import numpy as np
df = pd.DataFrame(
    {
        "nhs": [
            "9434765870",
            "9434765871",
            "51824753556",
            "51 824 753 556",
            "hello",
            np.nan,
            "NULL"
        ],
        "address": [
            "123 Pine Ave.",
            "main st",
            "1234 west main heights 57033",
            "apt 1 789 s maple rd manhattan",
            "robie house, 789 north main street",
            "(staples center) 1111 S Figueroa St, Los Angeles",
            "hello",
        ]
    }
)
df

	nhs	address
0	9434765870	123 Pine Ave.
1	9434765871	main st
2	51824753556	1234 west main heights 57033
3	51 824 753 556	apt 1 789 s maple rd manhattan
4	hello	robie house, 789 north main street
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles
6	NULL	hello

1. Default clean_gb_nhs

By default, clean_gb_nhs will clean nhs strings and output them in the standard format with proper separators.

from dataprep.clean import clean_gb_nhs
clean_gb_nhs(df, column = "nhs")

	nhs	address	nhs_clean
0	9434765870	123 Pine Ave.	943 476 5870
1	9434765871	main st	NaN
2	51824753556	1234 west main heights 57033	NaN
3	51 824 753 556	apt 1 789 s maple rd manhattan	NaN
4	hello	robie house, 789 north main street	NaN
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles	NaN
6	NULL	hello	NaN

2. Output formats

This section demonstrates the output parameter.

standard (default)

clean_gb_nhs(df, column = "nhs", output_format="standard")

	nhs	address	nhs_clean
0	9434765870	123 Pine Ave.	943 476 5870
1	9434765871	main st	NaN
2	51824753556	1234 west main heights 57033	NaN
3	51 824 753 556	apt 1 789 s maple rd manhattan	NaN
4	hello	robie house, 789 north main street	NaN
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles	NaN
6	NULL	hello	NaN

compact

clean_gb_nhs(df, column = "nhs", output_format="compact")

	nhs	address	nhs_clean
0	9434765870	123 Pine Ave.	9434765870
1	9434765871	main st	NaN
2	51824753556	1234 west main heights 57033	NaN
3	51 824 753 556	apt 1 789 s maple rd manhattan	NaN
4	hello	robie house, 789 north main street	NaN
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles	NaN
6	NULL	hello	NaN

3. inplace parameter

This deletes the given column from the returned DataFrame. A new column containing cleaned NHS strings is added with a title in the format "{original title}_clean".

clean_gb_nhs(df, column="nhs", inplace=True)

	nhs_clean	address
0	943 476 5870	123 Pine Ave.
1	NaN	main st
2	NaN	1234 west main heights 57033
3	NaN	apt 1 789 s maple rd manhattan
4	NaN	robie house, 789 north main street
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles
6	NaN	hello

4. errors parameter

coerce (default)

clean_gb_nhs(df, "nhs", errors="coerce")

	nhs	address	nhs_clean
0	9434765870	123 Pine Ave.	943 476 5870
1	9434765871	main st	NaN
2	51824753556	1234 west main heights 57033	NaN
3	51 824 753 556	apt 1 789 s maple rd manhattan	NaN
4	hello	robie house, 789 north main street	NaN
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles	NaN
6	NULL	hello	NaN

ignore

clean_gb_nhs(df, "nhs", errors="ignore")

	nhs	address	nhs_clean
0	9434765870	123 Pine Ave.	943 476 5870
1	9434765871	main st	9434765871
2	51824753556	1234 west main heights 57033	51824753556
3	51 824 753 556	apt 1 789 s maple rd manhattan	51 824 753 556
4	hello	robie house, 789 north main street	hello
5	NaN	(staples center) 1111 S Figueroa St, Los Angeles	NaN
6	NULL	hello	NaN

4. validate_gb_nhs()

validate_gb_nhs() returns True when the input is a valid NHS. Otherwise it returns False.

The input of validate_gb_nhs() can be a string, a Pandas DataSeries, a Dask DataSeries, a Pandas DataFrame and a dask DataFrame.

When the input is a string, a Pandas DataSeries or a Dask DataSeries, user doesn’t need to specify a column name to be validated.

When the input is a Pandas DataFrame or a dask DataFrame, user can both specify or not specify a column name to be validated. If user specify the column name, validate_gb_nhs() only returns the validation result for the specified column. If user doesn’t specify the column name, validate_gb_nhs() returns the validation result for the whole DataFrame.

from dataprep.clean import validate_gb_nhs
print(validate_gb_nhs("9434765870"))
print(validate_gb_nhs("9434765871"))
print(validate_gb_nhs("51824753556"))
print(validate_gb_nhs("51 824 753 556"))
print(validate_gb_nhs("hello"))
print(validate_gb_nhs(np.nan))
print(validate_gb_nhs("NULL"))

True
False
False
False
False
False
False

Series

validate_gb_nhs(df["nhs"])

0     True
1    False
2    False
3    False
4    False
5    False
6    False
Name: nhs, dtype: bool

DataFrame + Specify Column

validate_gb_nhs(df, column="nhs")

0     True
1    False
2    False
3    False
4    False
5    False
6    False
Name: nhs, dtype: bool

Only DataFrame

validate_gb_nhs(df)

	nhs	address
0	True	False
1	False	False
2	False	False
3	False	False
4	False	False
5	False	False
6	False	False